Co-reporter:Ming Su, Peiyun Chen, Yajuan Dong, Hanwen Sun
Journal of Luminescence 2016 Volume 177() pp:204-208
Publication Date(Web):September 2016
DOI:10.1016/j.jlumin.2016.04.051
Graphene quantum dots (GQDs) with particle size of 4.5±1.0 nm were prepared and characterized by transmission electron microscopy, UV–vis absorption spectroscopy and fluorescence spectroscopy. It was found that KMnO4 could oxidize GQDs to produce a relatively intense chemiluminescence (CL) emission. The mechanism of CL generation was investigated based on absorption spectra and CL emission spectra. CL emission was attributed to the radiative recombination of oxidant-injected holes and thermally excited electrons in the GQDs. On the other hand, both KMnO4 and ∙O2− could react with GQDs to produce GQDs∙+ and GQDs∙−. The electron-transfer annihilation of GQDs∙+ and GQDs∙− could form excited-state GQDs*, which acted as the final emitter in the system. In order to show the analytic potential of GQDs–KMnO4 CL system, it was applied for the determination of hydroquinone based on its diminishing effect. Under the optimized conditions, the proposed CL system exhibits excellent analytic performance for determination of hydroquinone. Calibration curve in the range of 2.49×10−4–9.96×10−7 g mL−1 was linear with the correlation coefficient (r) of 0.9924. The limit of detection was 8.46×10−8 g mL−1, and the relative standard deviation (RSD) was found to be 1.7% for 11 determinations of 4.98×10−6 g mL−1 hydroquinone. The applicability of the method was verified by applying to real tap water, lake water, and waste water samples. The recoveries were in the range of 89.7–97.1% with RSD of 0.9–2.1%. The proposed method has a good linearity, high sensitivity and good repeatability and can be applied for routine determination of hydroquinone in water.
Co-reporter:Shuxuan Liang, Xinfeng Dong, Ming Su and Hanwen Sun
Analytical Methods 2016 vol. 8(Issue 17) pp:3599-3604
Publication Date(Web):01 Apr 2016
DOI:10.1039/C6AY00327C
A novel ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) method was developed for the first time for the determination of herbicide atrazine (ATR) and its principal metabolites namely desisopropylatrazine (DIA), desethylatrazine (DEA) and hydroxyatrazine (HA) in cereals. The limit of detection ranged from 0.06 μg kg−1 (DEA) to 0.25 μg kg−1 (HA). The intra- and inter-day relative standard deviations (RSDs) for the four analytes were 5.5–9.3% and 8.7–17.1% for cereal grain samples, respectively. Recoveries for the four targets at three spiked levels ranged from 71.9 to 106% with RSD of 3.1–8.1% for the cereals. The content of the analytes in cereals was determined as follows: 0.6–3.0 μg kg−1 for ATR and 0.6–1.6 μg kg−1 for DEA, while DIA and HA were not detected. The proposed method can ensure a rapid and highly sensitive analysis of atrazine and its degradation products in cereals, and can provide a direction for proper application of atrazine and a base for evaluating their hazards to food safety.
Co-reporter:Zhe Meng, Zhihong Shi, Shuxuan Liang, Xinfeng Dong, Hui Li, Hanwen Sun
Food Chemistry 2015 Volume 174() pp:597-605
Publication Date(Web):1 May 2015
DOI:10.1016/j.foodchem.2014.11.067
•An UPLC–MS/MS method for multiclass and multiresidue analysis is developed.•Fragmentation pathway of fluoroquinolones, sulphonamides and metabolites was presented.•The quantification limits of the 17 analytes were well below the MRLs.•The method can ensure quantification analysis of bovine milk at low μg kg−1 level.A novel UPLC–MS/MS method for quantification and confirmation of eight fluoroquinolones, five sulphonamides (SAs) and four acetyled metabolites in milk is developed. Their main fragmentation pathways were presented. The limits of quantification were in the range of 0.01–0.29 μg kg−1 for FQs and 0.13–1.68 μg kg−1 for SAs. Mean recoveries ranging from 61% to 115% were achieved at spiked level of 0.5–100 μg kg−1. The intra- and inter-day precisions were in the range of 6.3–10.7% and 9.0–13.4%, respectively. This novel approach has high speed and sensitivity, and can ensure the multiclass and multiresidue analysis of bovine milk at low μg kg−1 level. The content of each analyte residue is much lower than the maximum residue limits. Some residues in milk were confirmed in according to the Commission Decision 657/2002/EC.
Co-reporter:Xingqiang Wu;Shuxuan Liang;Xusheng Ge;Yunkai Lv
Journal of Separation Science 2015 Volume 38( Issue 8) pp:1263-1270
Publication Date(Web):
DOI:10.1002/jssc.201401341
Dummy molecularly imprinted microspheres with danthron as template were synthesized and their performance was evaluated. Accelerated solvent extraction can rapidly and effectively remove template molecules from the microspheres. The microspheres were applied as a specific sorbent for solid-phase extraction of six anthraquinones from slimming tea, showing excellent affinity and high selectivity to danthron and the target analytes. The molecular recognition mechanisms were discussed by the experimental validation with IR spectroscopy. The sample was treated using accelerated solvent extraction followed by dummy molecularly imprinted microspheres solid-phase extraction. Under the optimized ultra high performance liquid chromatographic conditions, the six target analytes can be baseline separated in 8 min, and good linearity was obtained in a range of 0.1–40 μg/mL with the correlation coefficient (r2) of ≥0.9998. The method limit of quantification was in a range of 1–2 mg/kg, it can ensure analysis of anthraquinones at mg/kg level. The intra- and interday precision (RSD, n = 6) for the analysis of the six analytes in a slimming tea was less than 4.5 and 5.4%, respectively. The developed method can be applied for the selective extraction, effective separation, and rapid determination of six anthraquinones in slimming tea.
Co-reporter:Xinfeng Dong, Shuxuan Liang and Hanwen Sun
Analytical Methods 2015 vol. 7(Issue 5) pp:1884-1889
Publication Date(Web):08 Jan 2015
DOI:10.1039/C4AY02536A
A rapid, sensitive and selective method for simultaneous determination of seven anticoagulant rodenticide residues (warfarin, coumatetralyl, diphacinone, chlorophacinone, brodifacoum, bromadiolone, and flocoumafen) in human serum by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) has been developed and validated. Serum sample preparation was carried out rapidly and effectively by one-step protein precipitation and analytes extraction using methanol containing 10% acetone. Chromatographic separation was achieved within 10 min using a BEH C18 column (1.7 μm, 2.1 mm × 100 mm) and gradient elution with the mobile phase of 5 mM ammonium acetate aqueous solution–methanol. Good linearity was achieved over three orders of magnitude with a correlation coefficient (r2) of 0.9924–0.9994. The limits of detection for the seven rodenticides ranged from 0.06 μg L−1 (flocoumafen) to 1.5 μg L−1 (diphacinone). The intra- and inter-day relative standard deviations (RSDs) of the seven analytes at the three spiked levels (1 × LOQ, 5 × LOQ and 10 × LOQ) were in the range of 0.6–10.3% and 5.1–15.1%, respectively. The mean recoveries for the seven analytes at the three spiked levels (1 × LOQ, 5 × LOQ and 10 × LOQ) were in the range of 77.3–98.2% with RSDs of 0.58–11.1%. The proposed method was successfully applied for the analysis of the seven anticoagulant rodenticides in human serum.
Co-reporter:Xingqiang Wu;Xusheng Ge;Shuxuan Liang;Yunkai Lv
Food Analytical Methods 2015 Volume 8( Issue 5) pp:1124-1132
Publication Date(Web):2015 May
DOI:10.1007/s12161-014-9976-6
A novel analytical method is developed for effective separation and rapid simultaneous determination of anthraquinones in Tartary buckwheat by ultra-performance liquid chromatography coupled to a diode array detector (UPLC−DAD). A selective accelerated solvent extraction (SASE) procedure combines an accelerated solvent extraction (ASE) and cleanup in situ. SASE conditions were investigated and optimized in the details. Methanol/acetone (50:50, v/v) was selected as solvent for the extraction, and silica gel was selected as sorbents for clean-up. The SASE procedure simplified further the entire sample preparation chain and achieved satisfactory results in the analyses of anthraquinones compared with traditional extraction methods. The effective separation of six anthraquinones from an extract of Tartary buckwheat on an Acquity BEH C18 (2.1 mm × 50 mm, 1.7 μm) column using gradient elution was achieved within 7 min. Good linearity was achieved, with a correlation coefficient (r2) of ≥0.9998. The limit of detection (LOD) and the limit of quantification (LOQ) were in the range of 0.033–0.067 μg/mL and 0.1–0.2 μg/mL, respectively. Under the optimized conditions, good recovery (98.3–109 %) of the anthraquinones was achieved. The validated method is successfully applied to the quality assurance of the anthraquinones in Tartary buckwheat and its products.
Co-reporter:Xinfeng Dong, Zhihong Shi, Shuxuan Liang and Hanwen Sun
Analytical Methods 2014 vol. 6(Issue 17) pp:6939-6947
Publication Date(Web):08 Jul 2014
DOI:10.1039/C4AY01045K
A simple, rapid and reliable method was developed for multi-class and multi-residue analysis of herbicides in human serum by ultra-performance, liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS). Serum sample preparation was carried out by one-step protein precipitation and analytes extraction using acetonitrile. After centrifugation, an aliquot of 5 μL of supernatant was injected into a C18 column for the separation of 22 kinds of triazine and phenylurea herbicides using gradient program with water–acetonitrile as the mobile phase and the separation of 29 kinds of herbicides using gradient program with 5 mM ammonium acetate aqueous solution containing 0.1% v/v formic acid–acetonitrile as the mobile phase. An excellent linearity of most herbicides was observed from 0.1 μg L−1 up to 10.0 μg L−1. The limits of detection (LODs) in serum ranged from 0.03 to 6.00 μg L−1, and the limits of quantification (LOQs) ranged from 0.10 to 18.0 μg L−1. Intra- and inter-day precisions at three spiked levels were satisfactory for the 51 herbicides with the RSD of 1.02–10.0% and 1.09–12.0%, respectively. Extraction recoveries of 51 herbicides were satisfactory and ranged from 63.6% to 109% at the three spiked levels with RSDs of 1.06% to 12.0%. This UPLC-ESI-MS method is simple, accurate, and useful for multi-class multi-residue determination of herbicides and benefits clinical analysis and diagnosis.
Co-reporter:Hui Li, Na Sun, Jingxuan Zhang, Shuxuan Liang and Hanwen Sun
Analytical Methods 2014 vol. 6(Issue 2) pp:537-547
Publication Date(Web):18 Nov 2013
DOI:10.1039/C3AY41664J
A novel high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method is developed for multiresidue analysis of twenty five synthetic colorants in meat matrices with matrix solid phase dispersion (MSPD). Good linearity was obtained with a correlation coefficient of 0.9935–0.9999. The quantitation limits (LOQs) for 12 acidic colorants were in the range from 0.89 μg kg−1 (acid orange 2) to 50.4 μg kg−1 (ponceau 4R) except for tartrazine, and the LOQs for 13 basic colorants were in the range from 0.52 μg kg−1 (Rhodamine B) to 4.19 μg kg−1 (disperse blue 7); among them the LOQ for 4 triphenylmethane colorants was in the range of 0.77–0.96 μg kg−1 which is better than the minimum required performance limit (MRPL) of 2 μg kg−1 for the sum of malachite green and leucomalachite green. The average recoveries for all analytes at three spiked levels were in the range of 75.4–123% except for Rhodamine B, (120–130%), with a RSD of <11%. The results showed that the content of 8 allowable food colorants and 17 banned synthetic colorants was lower than their LOQ level. This MSPD-HPLC-MS/MS method has the advantages of being rapid, sensitive, accurate, and high-throughput, and can be applied for multiresidue analysis of synthetic colorants in meat products.
Co-reporter:Ning Wang, Yuanyuan Wu, Xingqiang Wu, Shuxuan Liang and Hanwen Sun
Analytical Methods 2014 vol. 6(Issue 14) pp:5133-5139
Publication Date(Web):15 May 2014
DOI:10.1039/C4AY00588K
Anthraquinones (aurantio-obtusin, emodin and rhein) cannot be determined simultaneously using capillary zone electrophoresis because aurantio-obtusin has a low solubility in water. Therefore, a novel nonaqueous capillary electrophoresis (NACE) method with diode-array detection was developed for effective separation and simultaneous determination of the three anthraquinones. A BGE solution of 40 mM NaAc–40 mM NH4Ac–40 mM NaOH in methanol was used for separation of the three anthraquinones. The effects of ultrasonic extraction conditions and the NACE conditions on separation were investigated in detail. Under the optimized conditions, the analytes can be effectively separated in 7 min. The standard curves of the three anthraquinones showed good linearity, with correlation coefficients of r > 0.999. The limit of detection (LOD; signal to noise ratio (S/N) of 3) of aurantio-obtusin, emodin and rhein were 0.25, 0.12 and 0.19 μg mL−1, respectively. Their average intra- and inter-day analytical precisions (relative standard deviation) were less than 2.8% and 4.0%, respectively. The recoveries of the three spiked levels of aurantio-obtusin, emodin and rhein from semen cassiae and cassia seed tea samples were in the range of 86.6–106%. The proposed method provides the speediness, selectivity, sensitivity, linearity and accuracy as well as low reagent consumption necessary for simultaneous analysis of the test anthraquinones. The ultrasonic extraction–NACE method was used for the analysis of aurantio-obtusin, emodin and rhein in semen cassiae and cassia seed tea with satisfactory results, and could be applied for quality control of semen cassiae and cassia seed tea.
Co-reporter:Yun Hao, Xinfeng Dong, Shuxuan Liang and Hanwen Sun
Analytical Methods 2014 vol. 6(Issue 7) pp:2356-2362
Publication Date(Web):23 Jan 2014
DOI:10.1039/C3AY41650J
A sensitive high-performance liquid chromatography (HPLC) method was developed for the determination of four anticoagulant rodenticide residues (warfarin, coumatetralyl, crimidine, and bromadiolone) in foodstuffs and body fluids. The conditions of accelerated solvent extraction (ASE) and HPLC were optimized. Good linearity was achieved with a correlation coefficient (r) of 0.9999. The limits of quantification for the four rodenticides ranged from 2.2 μg kg−1 (crimidine) to 13 μg kg−1 (bromadiolone) for solid samples and from 0.02 μg mL−1 (crimidine) to 0.15 μg mL−1 (bromadiolone) for liquid samples. The intra- and inter-day relative standard deviations (RSDs) of the four analytes at two spiked levels were in the range of 0.3–1.1% and 0.5–1.6%, respectively. The mean recoveries for warfarin, coumatetralyl, crimidine, and bromadiolone at the two spiked levels were in the range of 94–106% with RSDs of 0.3–1.1% for the rice and corn samples, and 87–108% with RSDs of 0.3–0.8% for the whole blood and urine samples. The proposed method has characteristics of high precision, sensitivity and accuracy as well as low consumption of the reagents. The proposed HPLC method was successfully applied for the analysis of the four anticoagulant rodenticides in rice, corn, whole blood, and urine samples.
Co-reporter:Xingqiang Wu;Xusheng Ge;Shuxuan Liang
Food Analytical Methods 2014 Volume 7( Issue 4) pp:774-782
Publication Date(Web):2014 April
DOI:10.1007/s12161-013-9680-y
A highly sensitive ultra-performance liquid chromatographic method with diode-array detection was developed for residue determination of thiophanate methyl (TM), cyromazine (CYR), and their metabolites, carbendazim (MBC) and melamine (MEL). Edible fungi samples were treated using accelerated solvent extraction (ASE) followed by cleanup with solid-phase extraction (SPE). Under optimized conditions, good linearity was achieved with a correlation coefficient (r2) of ≥0.9998. The limit of quantification was 0.36, 0.24, 0.4, and 0.5 μg kg−1 for MEL, CYR, MBC, and TM, respectively. The intra- and interday precisions (in terms of the relative standard deviation (RSD)) of the four analytes were in the range of 2.3–4.5 and 3.1–6.3 %, respectively. The recoveries for TM, MBC, CYR, and MEL in four edible fungi samples at three spiked levels of 0.6, 6, and 20 μg kg−1 for TM and MBC and 0.4, 4, and 20 μg kg−1 for CYR and MEL were in the range of 82–105 % with RSDs below 5.6 %. The proposed method can be used for the routine determination of CYR and MEL in edible fungi with high sensitivity and accuracy as well as low consumption of reagents.
Co-reporter:Hanwen Sun;Liya Xia;Shuzhen Liang;Shigang Shen
Food Analytical Methods 2014 Volume 7( Issue 9) pp:1791-1797
Publication Date(Web):2014 October
DOI:10.1007/s12161-014-9816-8
The determination of the geographical origin of foodstuffs is becoming of increasing interest to consumers and producers since it may be used as a criterion to certify quality and typicality. The correlation of inorganic anion contents in rice and its origin soils was studied in this paper, and the inorganic anion contents were used to identification the rice geographical origin. The contents of F−, Cl−, NO2−, NO3−, and SO42− in rice samples and soil samples from four provinces of China were analyzed by ion chromatography. The result of variance analysis and correlation analysis demonstrated that there is significant difference in the contents for F−, Cl−, NO2−, NO3−, and SO42− in the rice samples from four provinces, and the anions in rice are closely connected with the anions in soil. The predictions of geographic origin made by linear discriminant analysis (LDA) based on anions gave an overall correct classification rate of 100 % and cross-validation rate of 96.9 %. The correct rate of Q-type hierarchical cluster analysis (Q-type CA) was 81.3 %. These results demonstrate the usefulness of multi-anion fingerprints as indicators for authenticating the geographical origin of the four famous brand rices.
Co-reporter:Yanlei Yang;Hui Li;Jingxuan Zhang;Na Sun
Food Analytical Methods 2014 Volume 7( Issue 4) pp:798-805
Publication Date(Web):2014 April
DOI:10.1007/s12161-013-9683-8
A new method was developed for effective separation and simultaneous determination of estrogens, gestagens, and androgens, including estrone, 17β-estradiol, testosterone, progesterone, and estriol, in infant formula. The samples were enzymatically digested with β-glucuronidase/arylsulfatase prior to microwave-assisted extraction. After the extract was cleaned up by gel permeation chromatography the hormones were derivatived with 50 μL BSTFA containing 1 % TMCS. The derivatived hormones were measured with GC–MS/MS using electron impact ionization source in the positive multi-reaction monitoring mode. The calibration curves showed good linearity with correlation coefficient (r) of >0.999. The limit of quantification of five hormones ranged from 0.094 to 0.265 μg kg−1, which is below the minimum required performance limits established by the European Community. The intra- and inter-day precision (as RSD) for six determinations of five analytes at 40 μg kg−1 spiked level was in range of 3.4–5.4 % and 3.5–6.8 %, respectively. The recovery of five analytes was obtained to be 84.5–104 %, with relative standard deviations (RSD, n = 6) of 1.7–5.5 %. This method has been successfully used for the qualitatively and quantitatively determination of estrone, 17β-estradiol, testosterone, progesterone, and estriol in infant formula.
Co-reporter:Hanwen Sun, Ting Wang, Xuyang Liu, Peiyun Chen
Journal of Luminescence 2013 Volume 134() pp:154-159
Publication Date(Web):February 2013
DOI:10.1016/j.jlumin.2012.08.056
A sensitive inhibition chemiluminescence (CL) method for the determination of 6-mercaptopurine (6-MP) is developed. The mechanism of the CL reaction between Ag(III) complex {[Ag(HIO6)2]5−} and luminol in alkaline solution was proposed, along with the inhibition mechanism of 6-MP on the CL emission. The inhibition degree of CL emission was proportional to the logarithm of 6-MP concentration. The effects of the reaction conditions on CL emission and inhibition were examined. Under the optimized conditions, the detection limit (s/n=3) was 3.7×10−10 g ml−1. The recoveries of 6-MP were in the range of 97.7–105% with the RSD of 2.1–3.4% (n=5) for tablet samples, 103–106% with the RSDs of 1.1–2.1% for spiked serum sample, and 97.2–101% with the RSD of 2.0–4.5% for spiked urine sample. The accuracy of this method for the tablet analysis was examined by comparing with the pharmacopoeia method. The proposed method was used for the determination of 6-MP at clinically relevant concentrations in real urine and serum samples with satisfactory results.Highlights► A sensitive inhibition chemiluminescence (CL) method for the determination of 6-MP is developed. ► The inhibition mechanism of 6-MP on the CL emission was proposed. ► The detection limit was 3.7×10−10 g ml−1. ► The accuracy was examined by comparing with the pharmacopoeia method.
Co-reporter:Xianghua Xia and Hanwen Sun
Analytical Methods 2013 vol. 5(Issue 21) pp:6135-6140
Publication Date(Web):09 Sep 2013
DOI:10.1039/C3AY41024B
A curve fitting method based on an exponentially modified Gaussian (EMG) model-genetic algorithm was used in quantitative resolution for overlapped synchronous fluorescence spectra. The method was effective for overcoming mutual interference in the course of the multi-component quantitative analysis. In this work, a novel method is developed for the highly sensitive and simultaneous determination of three isomers of dihydroxybenzene (DHB) by synchronous fluorescence using curve fitting. The method can effectively correct the overlapping interferences of the fluorescence spectra of the three DHB isomers. Under the optimized experimental conditions, the good linear relationship between the fluorescence intensity and the concentration of catechol (o-DHB), resorcinol (m-DHB) and hydroquinone (p-DHB) was obtained in the range of 0.02–10 μg mL−1, 0.01–10 μg mL−1 and 0.01–10 μg mL−1 with a correlation coefficient of 0.9920, 0.9990 and 0.9996, respectively. Their detection limits were 0.005, 0.003, and 0.002 μg mL−1, respectively, and the recoveries were in the range of 84.0–117% with relative standard deviations of 0.3–2.9%. The proposed curve fitting–synchronous fluorescence method was rapid, simple and highly sensitive for the determination of the three DHB isomers in water samples without pre-separation. This method was validated for selectivity, sensitivity, linearity, recovery, accuracy, and precision, and was successfully applied for the monitoring of DHB isomers in environmental water fields.
Co-reporter:Yuanyuan Wu and Hanwen Sun
Analytical Methods 2013 vol. 5(Issue 21) pp:6017-6022
Publication Date(Web):15 Aug 2013
DOI:10.1039/C3AY40956B
The applicability of capillary zone electrophoresis for the simultaneous determination of cefamandole and probenecid in body fluids has been studied using salicylic acid as an internal standard. A 10 mM disodium tetraborate solution (pH 8.0) was used as a running buffer and the UV wavelength was set at 230 nm for monitoring the analytes at a separation voltage of 18 kV. Under the optimized conditions, the analytes can be effectively separated in 6 min. The standard curves of cefamandole and probenecid showed good linearity in the range of 10–200 and 5–110 μg mL−1, respectively, with correlation coefficients r > 0.999. The detection limits (S/N = 3) of cefamandole and probenecid were 2.7 and 1.1 μg mL−1, respectively. Intra- and inter-day analytical precisions (relative standard deviation, RSD) of peak area and migration time for the two medicines were both less than 2%. The recoveries at three spiked levels of cefamandole and probenecid from urine and serum samples were in the range of 96.23–105.1% with RSD values of 0.55–2.36%. The proposed method was tested for clinical application by the simultaneous determination of cefamandole and probenecid in human urine and serum with satisfactory results.
Co-reporter:Hanwen Sun and Haijing Qi
Analytical Methods 2013 vol. 5(Issue 1) pp:267-272
Publication Date(Web):12 Nov 2012
DOI:10.1039/C2AY26101D
Malachite green (MG), crystal violet (CV) and their leuco-metabolites (LMG, LCV) could not be determined simultaneously by capillary zone electrophoresis because of their similar structures, low solubility in water, and easy degradation/de-methylation. A novel capillary electrophoresis (CE) method with UV detection for the effective separation and simultaneous determination of the four compounds was developed for the first time. The use of an acetonitrile–sodium dodecyl sulfate (SDS)–ammonium acetate buffer solution (pH 4.0) achieved the effective separation of the four compounds. The effects of CE conditions on separation were investigated in detail. Accelerated solvent extraction (ASE) with acetonitrile as an extractant in the presence of hydroxylamine hydrochloride and p-toluenesulfonic acid was used to extract the four compounds in aquatic products with high extraction efficiency. Under optimized separation conditions, the four analytes could be baseline separated, and there was no interference in analysis of real samples. Calibration curves have good linearity with a correlation coefficient (r) greater than 0.999. The limit of detection for MG, CV, LMG, and LCV were 0.39, 0.29, 0.08, and 0.10 μg mL−1, respectively. The intra- and inter-day variability (RSD) of peak areas were in the range of 0.3–3.4% and 1.0–4.7%, respectively. Average recoveries were 92.6–107% with RSD of 2.1% for shrimp samples, 95.4–108% with RSD of 2.3% for eel samples, and 89.1–105% with RSD of 3.1% for sardine samples. The proposed ASE–CE method has the advantages of high selectivity, good linearity and precision.
Co-reporter:Hanwen Sun;Haijing Qi;Hui Li
Food Analytical Methods 2013 Volume 6( Issue 4) pp:1049-1055
Publication Date(Web):2013 August
DOI:10.1007/s12161-012-9509-0
A rapid and effective method was developed in the first time for the determination of four sulfonamides (SAs) and their N4-acetylated metabolites in aquatic products using capillary electrophoresis with accelerated solvent extraction (ASE). The eight residues were extracted with acetonitrile at 70 °C under 10.3 MPa pressure and two static cycles with a static time of 5 min. The eight analytes can be baseline separated with 6 min. The standard curves for the determination of eight residues by the capillary electrophoretic method have good linearity (r2 > 0.999). The method limits of quantification (LOQs) for N4-acetylsulfadiazine, sulfadiazine, sulfamerazine, sulfamethoxazole, sulfamethazine, N4-acetylsulfamethazine, N4-acetylsulfamerazine, and N4-acetylsulfamethoxazole in aquatic products were 26.4, 33.0, 33.0, 33.0, 39.6, 370, and 1,076 μg kg−1, respectively. Intra- and inter-day precision (RSD) were 0.4–2.2 % and 1.4–3.5 %, respectively. Their average recoveries with three spiked levels ranged from 83 % to 116 % with the RSDs less than 4 %. The proposed method provides a rapid and simple extraction procedure with high sensitivity and recoveries, and can permit routine detection of the studied SAs residues in aquatic products at the maximum residue level.
Co-reporter:Hanwen Sun;Na Sun;Hui Li;Jingxuan Zhang;Yanlei Yang
Food Analytical Methods 2013 Volume 6( Issue 5) pp:1291-1299
Publication Date(Web):2013 October
DOI:10.1007/s12161-012-9542-z
A novel ultrahigh performance liquid chromatographic method is developed for analysis of 21 synthetic colorants with different acid–base property, solubility, and polarity. The meat samples were extracted by microwave-assisted extraction followed by cleanup with solid-phase extraction. The effective separation of the colorants in meat matrixes was achieved, and no interfering peaks could be detected at the retention time of the analytes. The calibration curves showed good linearity with correlation coefficients of 0.9940–0.9999. The limits of quantification were 0.48–7.19 μg/kg. The average recovery of the 21 analytes from meat samples spiked with 25 and 75 μg kg−1 was 61.29–116.1 % with relative standard deviation (RSD) of <11 %. For blank beef sausage spiked with 50 μg kg−1 for each analyte, the intraday precision (as RSD) for 21 analytes was 1.45–9.21 % for six determinations within a day. This method has the advantages of being rapid, sensitive, accurate, and with high-throughput and can be applied for multiresidue analysis of meat samples, including six allowable azo food colorants, ten banned azo food colorants, four banned triphenylmethanes, and rhodamin B food colorant.
Co-reporter:Hanwen Sun;Juan Wang ;Ting Wang
Luminescence 2013 Volume 28( Issue 4) pp:592-596
Publication Date(Web):
DOI:10.1002/bio.2398
ABSTRACT
A novel chemiluminescence (CL) method was developed for the determination of cefazolin sodium based on the CL reaction between the [Cu(HIO6)2]5-Cu(III) complex and luminol in alkaline solution. Results showed that CL emission of Cu(III) complex–luminol in alkaline medium was significantly different from that in acidic medium. A possible mechanism of the enhanced effect of cefazolin on CL emission of the [Cu(HIO6)2]5-- luminol system was proposed. The effect of the reaction conditions on CL emissions was examined. Under optimized conditions, a good linear relationship was obtained between CL intensity and concentrations of cefazolin sodium in the range of 2.0 x 10-8 to 2.0 x 10-6 g/mL with a correlation coefficient of R2 = 0.9978. The limit of detection was 4.58 x 10-9 g/mL. The proposed method was applied for the determination of cefazolin sodium in real samples with recoveries of 82.0-109% with an RSD of 0.7-2.1%. The proposed method was successfully used for the determination of cefazolin sodium in injectable powder preparations and human urine with satisfactory results. Copyright © 2012 John Wiley & Sons, Ltd.
Co-reporter:Hanwen Sun, Xusheng Ge, Yunkai Lv, Anbang Wang
Journal of Chromatography A 2012 Volume 1237() pp:1-23
Publication Date(Web):11 May 2012
DOI:10.1016/j.chroma.2012.03.003
Accelerated solvent extraction (ASE) has become a popular green extraction technology for different classes of organic contaminants present in numerous kinds of food and feed for food safety. The parameters affecting ASE efficiency and application advancement of ASE in the analysis of organic contaminants, natural toxins compounds as well as bioactive and nutritional compounds in animal origin food, plant origin food and animal feed are reviewed in detail. ASE is a fully automated and reliable extraction technique with many advantages over traditional extraction techniques, so it could be especially useful for routine analyses of pollutants in food and feed.Highlights► Parameters affecting ASE efficiency. ► Multi-residue analysis. ► Organic contaminants, bioactive and nutritional compounds. ► Application of ASE in analysis of animal origin foods, plant origin foods and feeds.
Co-reporter:Hanwen Sun, Yanli Zuo, Haijing Qi and Yunkai Lv
Analytical Methods 2012 vol. 4(Issue 3) pp:670-675
Publication Date(Web):01 Feb 2012
DOI:10.1039/C2AY05700J
A rapid and effective accelerated solvent extraction (ASE)–capillary electrophoretic method was developed for the determination of fluoroquinolone and sulfonamide residues in aquatic products. Seven residues were extracted with acetonitrile at 80 °C under 10.3 MPa pressure in less than 25 min. The standard curves for the determination of seven residues by the capillary electrophoretic method have good linearity (r2 > 0.999). The method limits of quantification (LOQs) were 70–100 μg kg−1. Their average recoveries with three spiked levels ranged from 83% to 106%. Intra- and inter-day precision (RSD) were 2.3–4.9% and 3.1–6.5%, respectively. The method provides a rapid and simple extraction procedure with high recoveries, and has been applied for the determination of 4 fluoroquinolone and 4 sulfonamide residues in aquatic products with satisfactory results.
Co-reporter:Hanwen Sun;Zhansheng Kang;Hui Li;Jingxuan Zhang;Yunkai Lv
Food Analytical Methods 2012 Volume 5( Issue 4) pp:643-650
Publication Date(Web):2012 August
DOI:10.1007/s12161-011-9291-4
A new method for multi-residue determination of five synthetic glucocorticoids (betamethasone, dexamethasone, prednisone, prednisolone, and hydrocortisone) in milk powder is developed. The glucocorticoids in the samples were extracted with tert-butyl methyl ether under ultrasonication incubation, and then cleaned up through gel permeation chromatography. After C18 LC gradient elution separation using acetonitrile with 0.1% formic acid as a mobile phase, the eluents were determined by liquid chromatography–tandem mass spectrometry with multiple reaction monitoring and positive ionization modes. The effective separation for the five glucocorticoids was achieved. The limit of quantification of the method for testing five glucocorticoids in milk powder was in the range from 0.2 to 0.5 μg kg−1, which was lower than the maximum residue limits established by European Union for glucocorticoids in foods. Experiments on spiked samples of milk powder showed that the mean recoveries at addition level of 1.0, 3.0, and 5.0 μg kg−1 were in the range of 71.2% and 103%, and the relative standard deviation ranged from 4.7% to 16.8%. The calibration curves for these drugs between 1.0 and 100 μg l−1 showed good linearity, with correlation coefficient (r) more than 0.999. The real sample test showed that this method is sensitive and accurate. It can be used for qualitative and quantitative determination of studied glucocorticoid residues in milk powder samples.
Co-reporter:H. Sun;L. Wei;Y. Zuo;Y. Wu
Journal of the Iranian Chemical Society 2011 Volume 8( Issue 4) pp:1043-1051
Publication Date(Web):2011 December
DOI:10.1007/BF03246561
Gatifloxacin (GAFX), P-aminomethylbezoic acid (PAMBA), cefazolin (CFZL) and cefminox (CMNX) can be combined and administered perorally or intravenously, and are excreted mainly into the urine. A novel capillary zone electrophoresis (CZE) method was developed, for the first time, for an effective separation and simultaneous determination of the said four drugs in human urine. The electrophoresis conditions were investigated and optimized. A 25 mM borate buffer (pH 9.2) was used and the peak area was determined with UV detection. Under optimal conditions, the four drugs can be separated effectively. Good linearity was achieved with the correlation coefficients (r2) of > 0.999. The limit of detection (LOD) for PAMBA, GAFX, CFZL and CMNX was 5.8, 3.9, 7.8 and 15.0 μg ml−1, respectively. Their average recovery in human urine was 93.2, 98.3, 108 and 92.7%, respectively, with the RSDs ranging from 1.0% to 3.5%. The proposed method is simple, rapid and accurate, and provides the sensitivity and linearity necessary for the selective and simultaneous analysis of the test drugs in human urine at clinically relevant concentrations.
Co-reporter:Hanwen Sun;Xiaoli Liu;Yuanyuan Miao
Food Analytical Methods 2011 Volume 4( Issue 2) pp:251-257
Publication Date(Web):2011 June
DOI:10.1007/s12161-010-9144-6
A new, rapid, and sensitive method was developed for speciation analysis of inorganic arsenic in dietary supplements using slurry sampling hydride generation atomic absorption spectrometry. As(III) content was determined under 1% HCl acidity conditions using both inhibitory effect of 8-hydroxyquinoline (8-HQ) on As(V) and its enhancing effect on As(III). Total inorganic arsenic content was determined under 5% HCl acidity conditions using the enhancing effect of 8-HQ on both As(III) and As(V). The method detection limit (S/N = 3) was 4.0 μg kg-1 for As(III) and 4.5 μg kg-1 for total inorganic arsenic. This method was validated using the Chinese standard method (GB/T 5009.11-2003), in good agreement with total inorganic arsenic content in real samples. The developed method was successfully applied to the speciation analysis of inorganic arsenic in dietary supplements with satisfactory results.
Co-reporter:Lianfeng Ai, Hanwen Sun, Fengchi Wang, Ruichun Chen, Chunhai Guo
Journal of Chromatography B 2011 Volume 879(Issue 20) pp:1757-1763
Publication Date(Web):15 June 2011
DOI:10.1016/j.jchromb.2011.04.021
A new procedure has been described for the extraction of diclazuril (DIZ), toltrazuril (TOZ) and its two main metabolites toltrazuril sulphoxide (TZSO) and toltrazuril sulphone (TZS) from poultry tissues and eggs, using gel permeation chromatography (GPC). The analytes and the deuterated internal standard were extracted from the samples with ethyl acetate. The analytes were measured by LC coupled to an electrospray ionization tandem mass spectrometer operating in the negative ion mode. Excellent linear dynamic range was observed from 1 to 500 μg/L with the correlation coefficients (R2) better than 0.99 for all analytes. The method LOQ of the four analytes in real samples was 1.2 μg/kg for DIZ and TOZ, and 1.8 μg/kg for TZSO and TZS. These values are far lower than the maximum residue limits (MRLs) established by several control authorities. The developed method was accurate with overall recoveries in four matrices.
Co-reporter:Hanwen Sun;Peiyun Chen;Shasha Shi;Liqing Li
Luminescence 2011 Volume 26( Issue 5) pp:356-362
Publication Date(Web):
DOI:10.1002/bio.1238
ABSTRACT
A novel chemiluminescence (CL) method was developed for the determination of 10-hydroxycamptothecin(HCPT) based on the CL reaction between [Ag(HIO6)2]5− and luminol in alkaline solution. CL emission of Ag(III) complex–luminol in alkaline medium was very different from that in acidic medium. A possible mechanism of enhanced CL emission was suggested. The enhanced effect of HCPT on CL emission of the [Ag(HIO6)2]5−–luminol system was found. The enhanced degree of CL emission was proportional to HCPT concentration. The effect of the reaction conditions on CL emission was examined. Under optimal conditions, the limit of detection was 6.5 × 10−9 g mL−1. The proposed method was applied for the determination of HCPT in real samples with the recoveries of 93.2–109% with the RSD of 1.7–3.3%. Copyright © 2010 John Wiley & Sons, Ltd.
Co-reporter:Hanwen Sun;Bo Feng
Food Analytical Methods 2011 Volume 4( Issue 2) pp:240-244
Publication Date(Web):2011 June
DOI:10.1007/s12161-010-9145-5
A new method was established for the speciation of Se by hydride generation-atomic fluorescence spectrometry. Effective separation of organic and inorganic Se in Se-enriched eggs was achieved by precipitating albumen with trichloroacetic acid. The detection limit for Se was 0.07 μg L−1. The proposed method was successfully applied for the determination of organic and inorganic Se as well as total Se in Se-enriched eggs with the recovery of 90.1–112% and the relative standard deviation (n = 5) of 0.6–3.4%. Se in Se-enriched eggs presents mainly in organic forms, the content of which was three to seven times that of inorganic Se.
Co-reporter:Han-Wen SUN, Zhan-Sheng KANG, Hui LI
Chinese Journal of Analytical Chemistry 2010 Volume 38(Issue 9) pp:1272-1276
Publication Date(Web):September 2010
DOI:10.1016/S1872-2040(09)60066-9
A gel permeation chromatography-solid phase extraction-rapid resolution liquid chromatography-tandem mass spectrometry (GPC-SPE-RRLC-MS/MS) method was developed for the determination of 9 steroid hormone residues in beef tissue. The beef samples were enzymatically digested with β-glucuronidase/arylsulfatase, and then extracted with tert-butyl methyl ether under ultrasonication incubation. Cleanup was carried out with GPC followed by a further HLB SPE. After C18 RRLC gradient elution separation with acetonitrile-0.1% aqueous formic acid as a mobile phase, the eluents were qualitatively and quantitatively determined under multireaction monitoring (MRM) scan type with tandem mass analyzer. The limit of quantification (LOQ) was 0.2-0.7 μg kg−1, and the calibration curves showed good linearity with correlation coefficients larger than 0.999. At the spiked levels of 0.2, 1.0 and 4.0 μg kg−1, the average recoveries were in the range of 81.4%-110%, and the relative standard deviations (RSDs) were in the range of 2.17%-9.82% (n = 7). The test results of real sample showed this method is sensitive and accurate. The proposed method was used for the sensitive and accurate determination of 9 steroid hormone residues in high-fat and complex samples.
Co-reporter:Hanwen Sun, Lijing Wei, Yuanyuan Wu, Na Liu
Journal of Chromatography B 2010 Volume 878(Issue 21) pp:1899-1903
Publication Date(Web):1 July 2010
DOI:10.1016/j.jchromb.2010.05.017
A sensitive and selective capillary electrophoresis method is developed, for the first time, for effective separation and simultaneous determination of aminomethylbezoic acid (PAMBA), cefminox sodium (CMNX) and etamsylate (ETM). The electrophoresis conditions were investigated and optimized. A 25 mM phosphate solution (pH 8.5) was used as a buffer and the peak area was determined with UV detection at 216 nm wavelength under 18 kV separation voltage. Under optimal conditions, the three drugs can be separated effectively. Good linearity was achieved in 3.13–150 μg/mL for PAMBA, 6.25–150 μg/mL for CMNX and 3.13–150 μg/mL for ETM, with the correlation coefficients of >0.999. The limit of detection (LOD) for PAMBA, CMNX and ETM was 1.04, 2.08 and 1.04 μg/mL, respectively. Their recoveries in human urine were in the range from 90.2% to 101% with the RSD (n = 5) of 0.7–3.1%. The proposed method is simple, rapid and accurate, and provides the sensitivity and linearity necessary for analysis of the test drugs in human urine at clinically relevant concentrations.
Co-reporter:Hanwen Sun, Peiyun Chen, Fei Wang
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2009 Volume 74(Issue 3) pp:819-824
Publication Date(Web):15 October 2009
DOI:10.1016/j.saa.2009.08.021
A novel chemiluminescence (CL) system for the determination of norfloxacin (NFLX) is developed based on the direct CL reaction of [Ag(HIO6)2]5−–H2SO4–NFLX system. The possible mechanism of CL emission and enhancing effect was discussed by comparing UV, fluorescence and CL spectra. [Ag(HIO6)2]5− in the presence of H2SO4 could produce CL emission at 490 nm, this might be caused by the excited state (O2)2*. The enhancing effect of NFLX may be produced through an intermolecular energy transfer from part of (O2)2* to NFLX molecule and complex of Ag3+ and NFLX. The CL intensity emission intensity was linear in the range 1.34 × 10−8 to 5.44 × 10−6 g mL−1 with correlation coefficient of 0.9982. The detection limit (s/n = 3) was 3.10 × 10−9 g mL−1. The recovery was in the range of 90.0–104% with the RSD of 1.1–2.8%. The proposed flow injection CL method was applied satisfactorily for the determination of NFLX in capsule, human serum and urine.
Co-reporter:Hanwen Sun;Lixin Wang;Na Liu;Fengxia Qiao;Shuxuan Liang
Chromatographia 2009 Volume 70( Issue 11-12) pp:
Publication Date(Web):2009 December
DOI:10.1365/s10337-009-1355-x
Solid-phase extraction (SPE) and reversed-phase liquid chromatography (RP-LC) have been used for simple, sensitive simultaneous analysis of cyromazine and melamine residues in liquid milk and eggs. The conditions used for SPE and LC were investigated and optimized. A combined cation-exchange–reversed-phase cartridge was used for clean-up, and an ODS (C18) column (150 mm × 4.6 mm i.d., 5-μm particles) with 62:38 (v/v) 5 mm sodium lauryl sulfate (pH 3.4)–acetonitrile as mobile phase was used for RP-LC. Under the optimum conditions the method limit of detection (LOD) for both cyromazine and melamine was 6.2 μg kg−1 for liquid milk samples, and 11.5 μg kg−1 for egg samples. Average recovery of cyromazine and melamine from milk samples was 90.3%, RSD 4.6–5.6%, and 99.6%, RSD 3.2–4.7%, respectively. Average recovery of cyromazine and melamine from egg samples was 85.3%, RSD 1.0–4.7%, and 89.6%, RSD 3.1–5.0%, respectively. The method enables detection of melamine and cyromazine at levels as low as 20.7 μg kg−1 in liquid milk and 38.3 μg kg−1 in egg.
Co-reporter:Han-wen Sun, Feng-xia Qiao
Journal of Chromatography A 2008 Volume 1212(1–2) pp:1-9
Publication Date(Web):28 November 2008
DOI:10.1016/j.chroma.2008.09.107
Novel water-compatible molecularly imprinted polymers (MIPs) were synthesized in methanol–water systems with ofloxacin as templates and methacryclic acid as functional monomers. The MIPs were used as a special sorbent for the selective solid-phase extraction (SPE) of nine quinolones from urine samples, showing high affinity to the quinolones in aqueous environment. Its molecular recognition mechanisms were investigated by the molecular simulation and the experimental validation with UV and infrared spectrogram as well as 1H NMR. Binding capability and chromatographic characteristic were also evaluated. By using the water-compatible MIPs as SPE sorbents, the nine quinolones can be selectively extracted and enriched, while all matrices interferences were eliminated simultaneously. Under the optimal conditions of SPE and high performance liquid chromatography (HPLC), the good linearity of the method was obtained in a range of 0.05–30 μg/mL with the correlation coefficient of >0.999 and the relative standard division of 2.0–7.4%. The detection limits (s/n = 3) were in a range of 0.036–0.10 μg/mL. The proposed method was successfully applied for the selective extraction and separation of the studied quinolones in urine samples.
Co-reporter:Hanwen Sun;Pan He
Chromatographia 2008 Volume 68( Issue 11-12) pp:969-975
Publication Date(Web):2008 December
DOI:10.1365/s10337-008-0814-0
The binding of fluoroquinolones to the transport protein, human serum albumin (HSA), under simulated physiological conditions has been studied by capillary electrophoresis–frontal analysis (CE–FA). The binding of these drugs to human plasma was evaluated by using ultrafiltration and capillary electrophoresis. The free drug concentration [D]f at each HSA concentration was determined by the plateau height in the electropherograms and the calibration lines. The binding constants of fluoroquinolones and HSA were estimated using nonlinear regression with origin 7.5 software. The fluoroquinolones were found to show low affinity toward HSA, with binding constants ranging from 1.73 × 102 to 5.40 × 102 M−1. The percentages of protein binding (PB) for fluoroquinolones to HSA were between 8.6 and 22.2%, while the PB percentages for fluoroquinolones to human plasma were between 10.2 and 33.1%. It can be found that the PB percentages for fluoroquinolones to HSA are mostly lower than those for fluoroquinolones to human plasma. It suggests that HSA is the primary protein responsible for the binding of fluoroquinolones in human plasma. The thermodynamic parameters were obtained by CE–FA. The positive ∆H and ∆S values obtained by CE–FA showed that the binding reaction was an endothermic process, and the entropy drive the binding and hydrophobic interaction played major roles in the binding of fluoroquinolones to HSA.
Co-reporter:Hanwen Sun;Wei Zhao;Pan He
Chromatographia 2008 Volume 68( Issue 5-6) pp:425-429
Publication Date(Web):2008 September
DOI:10.1365/s10337-008-0701-8
A simple and sensitive capillary electrophoresis method with solid phase extraction was developed for the determination of sarafloxacin, ciprofloxacin, enrofloxacin and flumequine in milk. Solid-phase extraction with Oasis HLB cartridge column was used for the isolation of four fluoroquinolones in raw milk from a farm and fresh milk sample. Separation conditions of CE, including running buffer, voltage and temperature, were investigated and optimized. Baseline separation was achieved for the four fluoroquinolones under the developed conditions. Correlation coefficients greater than 0.9998 were obtained for all fluoroquinolones with a dynamic range from 1 up to 100 mg L−1. The intra-day precision was less than 5%, and the inter-day precision was less than 6%. The method recoveries of four fluoroquinolones were in the range of 70.9–90.6%. The detection limits for sarafloxacin, ciprofloxacin, enrofloxacin and flumequine was 19.8, 15.2, 13.3 and 15.9 μg kg−1, respectively, which allows positive detection of the fluoroquinolones at the targeted maximum residue levels in milk samples.
Co-reporter:Hanwen Sun;Liqing Li;Ming Su
Chromatographia 2008 Volume 67( Issue 5-6) pp:399-405
Publication Date(Web):2008 March
DOI:10.1365/s10337-008-0518-5
A new method was developed for the simultaneous determination of lidocaine, proline and lomefloxacin in human urine by capillary electrophoresis-electrochemiluminescence detection with Ru(bpy)32+. Conditions of the separation and detection were investigated and optimized. It was proved that 20 mM phosphate buffer at pH 6.7 could achieve the most favorable resolution, and the high sensitivity of detection was obtained by using the detection potential at 1.15 V and 5 mM Ru(bpy)32+–60 mM phosphate buffer at pH 7.6 in the detection reservoir. The detection limits were 0.02 μg mL−1 for lidocaine, 0.03 μg mL−1 for proline and 0.06 μg mL−1 for lomefloxacin. Relative standard deviations of the ECL intensity and the migration time were 3.5 and 1.1% for 6 μg mL−1 lidocaine, 3.2 and 1.0% for 6 μg mL−1 proline and 3.7 and 1.2% for 6 μg mL−1 lomefloxacin, respectively. A baseline separation for lidocaine, proline and lomefloxacin was achieved within 360 s. The developed method was successfully applied to determine the amounts of lidocaine, proline and lomefloxacin in human urine. The recovery and RSD were in the range of 93.3–97.2 and 3.8–4.9%, respectively.
Co-reporter:Hanwen Sun, Fengchi Wang, Lianfeng Ai
Journal of Chromatography A 2007 Volume 1175(Issue 2) pp:227-233
Publication Date(Web):21 December 2007
DOI:10.1016/j.chroma.2007.10.051
A liquid chromatographic–electrospray ionisation-tandem mass spectrometry method (LC–ESI-MS/MS) with solid extraction was developed and validated for the detection and determination of closantel residues in bovine tissues and milk. An acetonitrile–acetone mixture (80:20, v/v) was used for one-stage extraction of closantel residues in bovine tissues and milk samples, and the extract was cleaned by solid phase extraction with Oasis MAX cartridges. The mass spectrometer was operated in multiple reactions monitoring mode with negative electrospray interface. The limits of detection in different matrices were in the range of 0.008–0.009 μg/kg. The overall recoveries for bovine muscle, liver, kidney and milk samples spiked at four levels including MRL were in the range of 76.0–94.3%. The overall relative standard deviations were in the range of 3.57–8.61%. The linearity is satisfactory with a correlation coefficient (r2) of 0.9913–0.9987 at both concentration ranges of 0.02–100 μg/kg and 200–5000 μg/kg. The method is capable of identifying closantel residues at ≥0.02 μg/kg levels and was applied in the determination of closantel residues in animal origin foods.
Co-reporter:Xusheng Ge, Xingqiang Wu, Shuxuan Liang, Ming Su, Hanwen Sun
Journal of Food and Drug Analysis (July 2016) Volume 24(Issue 3) pp:579-585
Publication Date(Web):1 July 2016
DOI:10.1016/j.jfda.2016.01.003
An effective sample preparation procedure using an accelerated solvent extraction (ASE) procedure, followed by cleaning with melamine molecularly imprinted polymers solid-phase extraction (MISPE) was developed. A novel and highly sensitive ASE–MISPE–ultra-performance liquid chromatography (UPLC) method was developed for effective separation and simultaneous determination of dicyandiamide (DCD), cyromazine (CYR), and melamine (MEL) in complex animal tissue foods. Under optimized conditions, good linearity was achieved with a correlation coefficient (r) of 0.9999 in the range of at least two orders of magnitude. The limit of quantification of the method was 1.7 μg/kg, 5.0 μg/kg, and 3.2 μg/kg for DCD, MEL, and CYR, which was three orders of magnitude smaller than the maximum residue limits (MRLs). The intra- and inter-day precisions (in terms of the relative standard deviation, RSD) of the three analytes were in the range of 1.7–3.1% and 3.1–6.3%, respectively. The average recoveries of analytes from blank chicken, beef, mutton, pork, and pig liver samples spiked with the three levels varied from 91.2% to 107% with RSD of 1.7–8.3% for DCD, 89.0–104% with RSD of 2.1–6.1% for CYR, and 94.8–105% with RSD of 1.1–6.6% for MEL. The proposed method has the characteristics of speed, sensitivity, and accuracy, and can be used for the routine determination of DCD, CYR, and MEL at the μg/kg level in complex animal tissue foods.Download full-size image
Co-reporter:Yaqian Zhang, Xiang Li, Xiaomao Liu, Jinjie Zhang, ... Hanwen Sun
Journal of Dairy Science (December 2015) Volume 98(Issue 12) pp:8433-8444
Publication Date(Web):1 December 2015
DOI:10.3168/jds.2015-9826
A simple and rapid multi-class multi-residue analytical method was developed for the screening and quantification of veterinary drugs in milk by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). A total of 90 veterinary drugs investigated belonged to almost 20 classes including lincomycins, macrolides, sulfonamides, quinolones, tetracyclines, β-agonists, β-lactams, sedatives, β-receptor antagonists, sex hormones, glucocorticoids, nitroimidazoles, benzimidazoles, nitrofurans, and some others. A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure was developed for the sample preparation without the solid-phase extraction step. The linearity, sensitivity, accuracy, repeatability, and reproducibility of the method were fully validated. The response of the detector was linear for each target compound in a wide concentration range with a correlation coefficient (R2) of 0.9973 to 0.9999 (among them R2 > 0.999 for 73 of 90 analytes). The range of the limit of quantification for these compounds in the milk ranged from 0.10 to 17.30 μg/kg. The repeatability and reproducibility were in the range of 2.11 to 9.62% and 2.76 to 13.9%, respectively. The average recoveries ranged from 72.62 to 122.2% with the RSD (n = 6) of 1.30 to 9.61% at 3 concentration levels. For the screening method, the data of the precursor and product ions of the target analytes were simultaneously acquired under the all ions MS/MS mode in a single run. An accurate mass database for the confirmation and identification of the target compounds was established. The applicability of the screening method was verified by applying to real milk samples. The proposed analytical method allows the identification and confirmation of the target veterinary drugs at trace levels employing quick analysis time. Certain veterinary drugs were detected in some cases.
Co-reporter:
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 21) pp:
Publication Date(Web):
DOI:10.1039/C3AY40956B
The applicability of capillary zone electrophoresis for the simultaneous determination of cefamandole and probenecid in body fluids has been studied using salicylic acid as an internal standard. A 10 mM disodium tetraborate solution (pH 8.0) was used as a running buffer and the UV wavelength was set at 230 nm for monitoring the analytes at a separation voltage of 18 kV. Under the optimized conditions, the analytes can be effectively separated in 6 min. The standard curves of cefamandole and probenecid showed good linearity in the range of 10–200 and 5–110 μg mL−1, respectively, with correlation coefficients r > 0.999. The detection limits (S/N = 3) of cefamandole and probenecid were 2.7 and 1.1 μg mL−1, respectively. Intra- and inter-day analytical precisions (relative standard deviation, RSD) of peak area and migration time for the two medicines were both less than 2%. The recoveries at three spiked levels of cefamandole and probenecid from urine and serum samples were in the range of 96.23–105.1% with RSD values of 0.55–2.36%. The proposed method was tested for clinical application by the simultaneous determination of cefamandole and probenecid in human urine and serum with satisfactory results.
Co-reporter:
Analytical Methods (2009-Present) 2014 - vol. 6(Issue 2) pp:NaN547-547
Publication Date(Web):2013/11/18
DOI:10.1039/C3AY41664J
A novel high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method is developed for multiresidue analysis of twenty five synthetic colorants in meat matrices with matrix solid phase dispersion (MSPD). Good linearity was obtained with a correlation coefficient of 0.9935–0.9999. The quantitation limits (LOQs) for 12 acidic colorants were in the range from 0.89 μg kg−1 (acid orange 2) to 50.4 μg kg−1 (ponceau 4R) except for tartrazine, and the LOQs for 13 basic colorants were in the range from 0.52 μg kg−1 (Rhodamine B) to 4.19 μg kg−1 (disperse blue 7); among them the LOQ for 4 triphenylmethane colorants was in the range of 0.77–0.96 μg kg−1 which is better than the minimum required performance limit (MRPL) of 2 μg kg−1 for the sum of malachite green and leucomalachite green. The average recoveries for all analytes at three spiked levels were in the range of 75.4–123% except for Rhodamine B, (120–130%), with a RSD of <11%. The results showed that the content of 8 allowable food colorants and 17 banned synthetic colorants was lower than their LOQ level. This MSPD-HPLC-MS/MS method has the advantages of being rapid, sensitive, accurate, and high-throughput, and can be applied for multiresidue analysis of synthetic colorants in meat products.
Co-reporter:
Analytical Methods (2009-Present) 2014 - vol. 6(Issue 17) pp:
Publication Date(Web):
DOI:10.1039/C4AY01045K
A simple, rapid and reliable method was developed for multi-class and multi-residue analysis of herbicides in human serum by ultra-performance, liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS). Serum sample preparation was carried out by one-step protein precipitation and analytes extraction using acetonitrile. After centrifugation, an aliquot of 5 μL of supernatant was injected into a C18 column for the separation of 22 kinds of triazine and phenylurea herbicides using gradient program with water–acetonitrile as the mobile phase and the separation of 29 kinds of herbicides using gradient program with 5 mM ammonium acetate aqueous solution containing 0.1% v/v formic acid–acetonitrile as the mobile phase. An excellent linearity of most herbicides was observed from 0.1 μg L−1 up to 10.0 μg L−1. The limits of detection (LODs) in serum ranged from 0.03 to 6.00 μg L−1, and the limits of quantification (LOQs) ranged from 0.10 to 18.0 μg L−1. Intra- and inter-day precisions at three spiked levels were satisfactory for the 51 herbicides with the RSD of 1.02–10.0% and 1.09–12.0%, respectively. Extraction recoveries of 51 herbicides were satisfactory and ranged from 63.6% to 109% at the three spiked levels with RSDs of 1.06% to 12.0%. This UPLC-ESI-MS method is simple, accurate, and useful for multi-class multi-residue determination of herbicides and benefits clinical analysis and diagnosis.
Co-reporter:
Analytical Methods (2009-Present) 2014 - vol. 6(Issue 14) pp:
Publication Date(Web):
DOI:10.1039/C4AY00588K
Anthraquinones (aurantio-obtusin, emodin and rhein) cannot be determined simultaneously using capillary zone electrophoresis because aurantio-obtusin has a low solubility in water. Therefore, a novel nonaqueous capillary electrophoresis (NACE) method with diode-array detection was developed for effective separation and simultaneous determination of the three anthraquinones. A BGE solution of 40 mM NaAc–40 mM NH4Ac–40 mM NaOH in methanol was used for separation of the three anthraquinones. The effects of ultrasonic extraction conditions and the NACE conditions on separation were investigated in detail. Under the optimized conditions, the analytes can be effectively separated in 7 min. The standard curves of the three anthraquinones showed good linearity, with correlation coefficients of r > 0.999. The limit of detection (LOD; signal to noise ratio (S/N) of 3) of aurantio-obtusin, emodin and rhein were 0.25, 0.12 and 0.19 μg mL−1, respectively. Their average intra- and inter-day analytical precisions (relative standard deviation) were less than 2.8% and 4.0%, respectively. The recoveries of the three spiked levels of aurantio-obtusin, emodin and rhein from semen cassiae and cassia seed tea samples were in the range of 86.6–106%. The proposed method provides the speediness, selectivity, sensitivity, linearity and accuracy as well as low reagent consumption necessary for simultaneous analysis of the test anthraquinones. The ultrasonic extraction–NACE method was used for the analysis of aurantio-obtusin, emodin and rhein in semen cassiae and cassia seed tea with satisfactory results, and could be applied for quality control of semen cassiae and cassia seed tea.
Co-reporter:
Analytical Methods (2009-Present) 2012 - vol. 4(Issue 3) pp:
Publication Date(Web):
DOI:10.1039/C2AY05700J
A rapid and effective accelerated solvent extraction (ASE)–capillary electrophoretic method was developed for the determination of fluoroquinolone and sulfonamide residues in aquatic products. Seven residues were extracted with acetonitrile at 80 °C under 10.3 MPa pressure in less than 25 min. The standard curves for the determination of seven residues by the capillary electrophoretic method have good linearity (r2 > 0.999). The method limits of quantification (LOQs) were 70–100 μg kg−1. Their average recoveries with three spiked levels ranged from 83% to 106%. Intra- and inter-day precision (RSD) were 2.3–4.9% and 3.1–6.5%, respectively. The method provides a rapid and simple extraction procedure with high recoveries, and has been applied for the determination of 4 fluoroquinolone and 4 sulfonamide residues in aquatic products with satisfactory results.
Co-reporter:Hanwen Sun and Haijing Qi
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 1) pp:NaN272-272
Publication Date(Web):2012/11/12
DOI:10.1039/C2AY26101D
Malachite green (MG), crystal violet (CV) and their leuco-metabolites (LMG, LCV) could not be determined simultaneously by capillary zone electrophoresis because of their similar structures, low solubility in water, and easy degradation/de-methylation. A novel capillary electrophoresis (CE) method with UV detection for the effective separation and simultaneous determination of the four compounds was developed for the first time. The use of an acetonitrile–sodium dodecyl sulfate (SDS)–ammonium acetate buffer solution (pH 4.0) achieved the effective separation of the four compounds. The effects of CE conditions on separation were investigated in detail. Accelerated solvent extraction (ASE) with acetonitrile as an extractant in the presence of hydroxylamine hydrochloride and p-toluenesulfonic acid was used to extract the four compounds in aquatic products with high extraction efficiency. Under optimized separation conditions, the four analytes could be baseline separated, and there was no interference in analysis of real samples. Calibration curves have good linearity with a correlation coefficient (r) greater than 0.999. The limit of detection for MG, CV, LMG, and LCV were 0.39, 0.29, 0.08, and 0.10 μg mL−1, respectively. The intra- and inter-day variability (RSD) of peak areas were in the range of 0.3–3.4% and 1.0–4.7%, respectively. Average recoveries were 92.6–107% with RSD of 2.1% for shrimp samples, 95.4–108% with RSD of 2.3% for eel samples, and 89.1–105% with RSD of 3.1% for sardine samples. The proposed ASE–CE method has the advantages of high selectivity, good linearity and precision.
Co-reporter:
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 21) pp:
Publication Date(Web):
DOI:10.1039/C3AY41024B
A curve fitting method based on an exponentially modified Gaussian (EMG) model-genetic algorithm was used in quantitative resolution for overlapped synchronous fluorescence spectra. The method was effective for overcoming mutual interference in the course of the multi-component quantitative analysis. In this work, a novel method is developed for the highly sensitive and simultaneous determination of three isomers of dihydroxybenzene (DHB) by synchronous fluorescence using curve fitting. The method can effectively correct the overlapping interferences of the fluorescence spectra of the three DHB isomers. Under the optimized experimental conditions, the good linear relationship between the fluorescence intensity and the concentration of catechol (o-DHB), resorcinol (m-DHB) and hydroquinone (p-DHB) was obtained in the range of 0.02–10 μg mL−1, 0.01–10 μg mL−1 and 0.01–10 μg mL−1 with a correlation coefficient of 0.9920, 0.9990 and 0.9996, respectively. Their detection limits were 0.005, 0.003, and 0.002 μg mL−1, respectively, and the recoveries were in the range of 84.0–117% with relative standard deviations of 0.3–2.9%. The proposed curve fitting–synchronous fluorescence method was rapid, simple and highly sensitive for the determination of the three DHB isomers in water samples without pre-separation. This method was validated for selectivity, sensitivity, linearity, recovery, accuracy, and precision, and was successfully applied for the monitoring of DHB isomers in environmental water fields.
Co-reporter:
Analytical Methods (2009-Present) 2014 - vol. 6(Issue 7) pp:NaN2362-2362
Publication Date(Web):2014/01/23
DOI:10.1039/C3AY41650J
A sensitive high-performance liquid chromatography (HPLC) method was developed for the determination of four anticoagulant rodenticide residues (warfarin, coumatetralyl, crimidine, and bromadiolone) in foodstuffs and body fluids. The conditions of accelerated solvent extraction (ASE) and HPLC were optimized. Good linearity was achieved with a correlation coefficient (r) of 0.9999. The limits of quantification for the four rodenticides ranged from 2.2 μg kg−1 (crimidine) to 13 μg kg−1 (bromadiolone) for solid samples and from 0.02 μg mL−1 (crimidine) to 0.15 μg mL−1 (bromadiolone) for liquid samples. The intra- and inter-day relative standard deviations (RSDs) of the four analytes at two spiked levels were in the range of 0.3–1.1% and 0.5–1.6%, respectively. The mean recoveries for warfarin, coumatetralyl, crimidine, and bromadiolone at the two spiked levels were in the range of 94–106% with RSDs of 0.3–1.1% for the rice and corn samples, and 87–108% with RSDs of 0.3–0.8% for the whole blood and urine samples. The proposed method has characteristics of high precision, sensitivity and accuracy as well as low consumption of the reagents. The proposed HPLC method was successfully applied for the analysis of the four anticoagulant rodenticides in rice, corn, whole blood, and urine samples.
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