Co-reporter:Qingying Liu;Jiufeng Li;Xuqin Song;Meiyu Zhang;Erfen Li;Fuming Gao;Limin He
RSC Advances (2011-Present) 2017 vol. 7(Issue 3) pp:1251-1259
Publication Date(Web):2017/01/04
DOI:10.1039/C6RA26581B
A sensitive, rapid and reproducible method has been developed based on high performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD) for the simultaneous detection of ten aminoglycoside antibiotics including apramycin, neomycin, amikacin, and gentamicin. The influence of parameters of ELSD on the responses of aminoglycosides was investigated in detail. The target analytes were separated well on a Hypersil BDS C18 column based on ion-pair chromatography. The proposed method was applied to the determination of eight drugs in various animal feeds. Calibration curves of eight aminoglycosides were linear (r ≥ 0.997) within the range of 2.00–200 μg mL−1. The recoveries of eight aminoglycosides from 5 types of animal feeds ranged from 61.2% to 104.0% and the intra- and inter-day relative standard deviations were less than 15%. The limits of detection of the eight aminoglycoside drugs were between 0.2 and 0.7 mg kg−1.
Co-reporter:Xuqin Song, Tong Zhou, Qingying Liu, Meiyu Zhang, Chenying Meng, Jiufeng Li, Limin He
Food Chemistry 2016 Volume 208() pp:169-176
Publication Date(Web):1 October 2016
DOI:10.1016/j.foodchem.2016.03.070
•The MIP was synthesized and used as a packing of solid-phase extraction.•LC–MS/MS was used for the determination of macrolide drugs residues in muscles.•Mean recoveries for ten macrolides were from 60.7% to 100.3% with RSD <14%.•The limits of detection for ten macrolides were between 0.1 and 0.4 μg kg−1.A simple and sensitive method based on molecularly imprinted solid-phase extraction coupled with liquid chromatography–tandem mass spectrometry was developed for the determination of the residues of ten macrolide drugs in swine, cattle and chicken muscles samples. The molecularly imprinted polymers (MIPs) were synthesized using tylosin as a template and methacrylic acid as a functional monomer. Samples were extracted with sodium borate buffer solution and ethyl acetate, and purified by the MIP cartridge. The results showed that the cartridge exhibited good recognition performance for macrolides, and better purification effect than the traditional solid-phase extraction cartridges. Recoveries of analytes at three spiking levels 1, 5 and 20 μg kg−1 ranged from 60.7% to 100.3% with the relative standard deviations less than 14%. The limits of detection of the method were between 0.1 and 0.4 μg kg−1. The method is useful for the routine monitoring of the residues of macrolide drugs in animal muscles.
Co-reporter:LiQi Wang, ZhenLing Zeng, Zhong Wang and LiMin He
RSC Advances 2016 vol. 6(Issue 32) pp:26967-26976
Publication Date(Web):02 Mar 2016
DOI:10.1039/C5RA28050H
In the residue analysis of nine β-agonists, namely salbutamol, terbutaline, cimaterol, fenoterol, clorprenaline, ractopamine, tulobuterol, clenbuterol and penbuterol in porcine liver, muscle and urine with liquid chromatography tandem mass spectrometry (LC-MS/MS), solvent calibration (SC) and matrix-matched calibration (MC) were compared using analysis of covariance to estimate the matrix effects (MEs) for all the analytes. Significant differences (P < 0.05) between the SC and MC were found for most analytes, indicating that the matrix induces systematic or proportional errors in the quantification of those analytes. In such cases, a correction function (CF) is proposed, with which the real concentration of analytes could be predicted using a SC. The results of the validation study showed that recoveries of the analytes calculated using the CF were comparable to those calculated using the MC, suggesting that the CF could be satisfactorily applied to the correction of MEs and the quantification of β-agonists in their residue analysis in porcine liver, muscle and urine by LC-MS/MS.
Co-reporter:Tong Zhou;Haicui Yang;Zhen Jin;Qingying Liu;Xuqin Song;Limin He;Binghu Fang;Chenying Meng
Journal of Separation Science 2016 Volume 39( Issue 7) pp:1339-1346
Publication Date(Web):
DOI:10.1002/jssc.201501249
Using spiramycin as a dummy template, a molecularly imprinted polymer monolithic micro-column with high selection to azithromycin was prepared in a micropipette tip. The imprinting factor of the monolithic micro-column prepared was approximately 2.67 and the morphological structure of the polymers was characterized by scanning electron microscopy. A simple, sensitive, and reproducible method based on the imprinted monolithic micro-column coupled to liquid chromatography with tandem mass spectrometry was developed for determining the residues of azithromycin in pork. Pork samples were extracted with acetonitrile, cleaned up under the optimal monolithic micro-column conditions, and analyzed using liquid chromatography with tandem mass spectrometry in the multiple reaction monitoring mode. The assay exhibited a linear dynamic range of 0.50–50 μg/L with the correlation coefficient (r2) above 0.99. In the three spiking levels of 0.50, 1.0, and 10 μg/kg, the average recoveries of azithromycin from pork samples were between 85.8 and 96.5% with a relative standard deviation below 10%. The limit of detection and limit of quantitation were 0.03 and 0.1 μg/kg, respectively.
Co-reporter:LiQi Wang;ZhenLing Zeng;Zhong Wang;JianYing Guo;LiMin He
Food Analytical Methods 2016 Volume 9( Issue 7) pp:1904-1911
Publication Date(Web):2016 July
DOI:10.1007/s12161-015-0359-4
The influence of water in samples on matrix effects and recoveries of analytes were investigated during the determination of residues of nine beta-agonists including salbutamol, terbutaline, cimaterol, fenoterol, clorprenaline, ractopamine, tulobuterol, clenbuterol, and penbuterol in porcine liver, muscle, and urine samples with liquid chromatography tandem mass spectrometry. Lyophilization procedure was adopted for sample moisture removal. The results showed that there were weak suppression effects for all target analytes except ractopamine, and no significant differences were found between fresh and lyophilized samples with respect to matrix effects of nine beta-agonists (P > 0.05). However, most analytes’ recoveries in the range of 85.0–115 % were obtained in lyophilized samples, while only a few ones were found in fresh samples. There are significant differences in recoveries for most analytes between fresh and lyophilized samples (P < 0.05). In conclusion, water in sample matrices does not affect matrix effects significantly while it might be one of the reasons causing poor recovery. Water removal is effective to improve recoveries of analytes without increasing matrix effects.
Co-reporter:Kui Bian, YaHong Liu, ZongNan Wang, Tong Zhou, XuQin Song, FangYu Zhang and LiMin He
RSC Advances 2015 vol. 5(Issue 35) pp:27584-27593
Publication Date(Web):02 Mar 2015
DOI:10.1039/C4RA13919D
Antimicrobial residues in environmental matrices may result in the occurrence of antimicrobial-resistant bacteria in soil. In this paper, a new analytical method based on liquid chromatography-tandem mass spectrometry for multiresidue analysis of 24 antimicrobials of a wide polarity range and variable physicochemical properties, including sulfonamides, tetracyclines, fluoroquinolones, macrolides, lincosamides and pleuromutilins in soil was developed. Samples were extracted with an acetonitrile: Na2EDTA–McIlvaine buffer (pH 4.0, 5:5, v/v) system and then re-extracted with a 0.2 M sodium hydroxide solution. The extracts were purified using an HLB solid phase extraction cartridge. Chromatographic separation of the components was performed on a Zorbax SB-Aq column using acetonitrile–0.1% formic acid as mobile phase. The method developed was linear in a concentration range from the limits of quantification to 200 μg kg−1, with correlation coefficients higher than 0.99. The limits of detection and limits of quantification ranged from 0.01 to 2 μg kg−1 and 0.04 to 5 μg kg−1, respectively. The overall average recoveries for target analytes were more than 60% except for tetracycline (59.3%) in three spiked levels of 1, 4 and 20 μg kg−1 with relative standard deviations less than 20%. The method was further applied for the determination of residual antimicrobials in real samples. Some target antimicrobials were detected at different levels and tetracycline residues were dominant. 163.6 μg kg−1 of chlortetracycline was detected in a soil sample. The results indicate that the proposed method has good feasibility.
Co-reporter:Zongnan Wang, Xuqin Song, Tong Zhou, Kui Bian, Fangyu Zhang, Limin He and Qingying Liu
RSC Advances 2015 vol. 5(Issue 2) pp:1491-1499
Publication Date(Web):24 Nov 2014
DOI:10.1039/C4RA12623H
A sensitive and reproducible method based on high performance liquid chromatography with evaporation light scattering detection (ELSD) was developed for the simultaneous determination of 10 macrolides drugs such as azithromycin, tulathromycin, spiramycin, tilmicosin, tylosin, erythromycin, clarithromycin, roxithromycin, midecamycin and josamycin in feeds. Feed samples were extracted with a sodium borate buffer solution (pH 10.0) − ethyl acetate. The dry extracts were dissolved in a phosphate buffer solution (pH 8.0), and then applied to an Oasis HLB solid-phase extraction cartridge for cleanup. The residues were reconstituted in 0.5 mL of the mobile phase. By optimizing the main operational parameters of ELSD and chromatographic conditions, all target compounds were well separated on an Ecosil C8-SH column (250 mm × 4.6 mm, 5 μm) using a gradient elution program. The calibration curves showed good linearity (r > 0.9985) in the range of 1–200 μg mL−1 for ten analytes. The average recoveries of all analytes from five kinds of feeds spiked at three levels were between 60.2% and 112%, with intra-day and inter-day relative standard deviations below 11% and 15%, respectively. The limits of detection ranged from 0.4 to 0.8 mg kg−1 for ten macrolides.
Co-reporter:Jianwen Yang, Zongnan Wang, Tong Zhou, Xuqin Song, Qingyong Liu, Yuman Zhang, Limin He
Journal of Chromatography B 2015 990() pp: 39-44
Publication Date(Web):
DOI:10.1016/j.jchromb.2015.03.009
Co-reporter:Fengyang Hu, Kui Bian, Yahong Liu, Yijuan Su, Tong Zhou, Xuqin Song, Limin He
Journal of Chromatography A 2014 Volume 1368() pp:52-63
Publication Date(Web):14 November 2014
DOI:10.1016/j.chroma.2014.09.074
•A new method for determination of antimicrobial residues in vegetables by LC-MS/MS.•A modified QuEChERS technique was used to extract and purify analytes.•The CCαs for 26 analytes in vegetable matrices were between 0.005 and 0.5 μg/kg.•Chlortetracycline, enrofloxacin and lincomycin in local vegetables were detected.A modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed for rapid determination of 26 veterinary antimicrobials in vegetables. Samples were extracted by single-phase extraction with acetonitrile-methanol (85:15, v/v) and citric buffer solution, followed by liquid–liquid partitioning with the addition of anhydrous magnesium sulfate and sodium chloride. A dispersive solid-phase extraction with primary secondary amine was applied for cleanup. Concentration and solvent exchange was performed prior to LC-MS/MS analysis. All matrix-matched calibration curves were linear with correlation coefficients (r) over 0.99. Recoveries for all the analytes spiked at 0.5 (1 or 1.5), 5 and 50 ng/mL were in the range of 60.0–98.0%, except for sulfaquinoxaline, sulfaclozine and doxycycline, with relative standard deviations below 25% for the low concentration level, 20% for the medium and 15% for the high. The decision limits and the detection capabilities of the analytes ranged from 0.005 to 0.5 μg/kg and from 0.02 to 1.5 μg/kg, respectively. The method was developed and validated in accordance with romaine lettuce matrix, and higher recovery rates were obtained from the other five kinds of vegetables including white radish, Chinese cabbage, cucumber, string bean and green pepper. Matrix effects of different vegetables were evaluated and signal suppression effect was observed for the majority of 26 analytes. Finally, the method was applied to the analysis of real samples collected from the agricultural areas in the vicinity of local pig farms, and the phenomenon of vegetables contaminated by antimicrobials residues is provoking.
Co-reporter:Liqi Wang, Zhenling Zeng, Xianhui Huang, Yijuan Su and Limin He
RSC Advances 2014 vol. 4(Issue 49) pp:25719-25728
Publication Date(Web):23 May 2014
DOI:10.1039/C4RA01678E
It was first confirmed that 5 glycerophospholipids (GPs, (15.6 mg L−1)), including lysophosphatidylcholine (LPC C18:0), lysophosphatidylcholine, LPC (C16:0), phatidylcholine, PC (C16:0/C18:2), phatidylcholine, PC (C16:0/C18:1) and phatidylethanolamine, PE (C18:0/C20:4), could significantly suppress the ionization of nine beta-agonists (2 μg L−1) using post-column infusion during liquid chromatography-electrospray tandem mass spectrometry analyses. Under optimal experimental conditions, most beta-agonists such as fenoterol, clorprenaline, tulobuterol, clenbuterol and especially penbuterol were co-eluted with GPs, and a positive linear correlation (R2 > 0.85) between the amount of GPs and the extent of ionization suppression was observed for the five analytes. In addition, the linear correlation was statistically significant (p < 0.001). GPs including LPC C18:0 (m/z 496.2), PC C16:0/C18:2 (m/z 758.5), PC C16:0/C18:1 (m/z 760.5), PE C18:0/C20:4 (m/z 768.6) and plasmalogen phosphatidylcholine, PLPC C18 (Plasm)/C18:1 (m/z 772.6) were detected in the final extracts of porcine liver sample. These endogenous GPs may be the main effectors that cause matrix effects in beta-agonist residue detection in porcine liver.
Co-reporter:Xufeng Wang, Yanghong Liu, Yijuan Su, Jianwen Yang, Kui Bian, Zongnan Wang, and Li-Min He
Journal of Agricultural and Food Chemistry 2014 Volume 62(Issue 2) pp:516-527
Publication Date(Web):December 23, 2013
DOI:10.1021/jf404501j
A new analytical strategy based on liquid chromatography–tandem mass spectrometry (LC-MS/MS) combined with accurate mass high-resolution Orbitrap mass spectrometry (HR-Orbitrap MS) was performed for high-throughput screening, confirmation, and quantification of 22 banned or unauthorized veterinary drugs in feedstuffs according to Bulletin 235 of the Ministry of Agriculture, China. Feed samples were extracted with acidified acetonitrile, followed by cleanup using solid-phase extraction cartridge. The extracts were first screened by LC-MS/MS in a single selected reaction monitoring mode. The suspected positive samples were subjected to a specific pretreatment for confirmation and quantification of analyte of interest with LC-MS/MS and HR-Orbitrap MS. Mean recoveries for all target analytes (except for carbofuran and chlordimeform, which were about 35 and 45%, respectively) ranged from 52.2 to 90.4%, and the relative standard deviations were <15% except for 20% for carbofuran. The decision limits (CCαs) for target analytes in formulated feed were between 2.6 and 23 μg/kg, and the detection capabilities (CCβs) were between 4.2 and 34 μg/kg. The method was successfully applied to screening of real samples obtained from local feed markets and confirmation of the suspected target analytes. It provides a high-throughput, sensitive, and reliable screening, identification, and quantification of banned veterinary drugs in routine monitoring programs of feedstuffs.
Co-reporter:Qianqian He;Binghu Fang;Yijuan Su;Zhenling Zeng;Jianwen Yang;Limin He;Dongping Zeng
Journal of Separation Science 2013 Volume 36( Issue 2) pp:301-310
Publication Date(Web):
DOI:10.1002/jssc.201200701
A simple, selective, and reproducible molecularly imprinted SPE coupled with HPLC method was developed for monitoring quinoxaline-1,4-dioxides in feeds. Molecularly imprinted polymers were synthesized in methanol using mequindox (MEQ) as template molecule and acrylamide as functional monomer by bulk polymerization. Under the optimum SPE conditions, the novel polymer sorbents can selectively extract and enrich carbadox, MEQ, quinocetone, and cyadox from a variety of feeds. The molecularly imprinted SPE cartridge was better than nonimprinted, C18, and HLB cartridges in terms of both recovery and precision. Mean recoveries of four quinoxaline-1,4-dioxides from six kinds of feeds spiked at 1.0, 10, and 100 mg/kg ranged between 75.2 and 94.7% with RSDs of less than 10%. The decision limits (CCαs) and the detection capabilities (CCβs) of four analytes were 0.15–0.20 mg/kg and 0.44–0.56 mg/kg, respectively. The class selectivity of the polymers was evaluated by checking three drugs with different molecular structures to that of MEQ.
Co-reporter:Li-Qi Wang, Zhen-Ling Zeng, Yi-Juan Su, Gao-Kui Zhang, Xiu-Ling Zhong, Zheng-Peng Liang, and Li-Min He
Journal of Agricultural and Food Chemistry 2012 Volume 60(Issue 25) pp:6359-6363
Publication Date(Web):June 6, 2012
DOI:10.1021/jf301440u
The synergistic influences of analyte concentration, sample source, and solid-phase extraction (SPE) type on matrix effects in the multiresidue analyses of eight β-agonists with LC-ESI-MS/MS were evaluated. Porcine muscle and liver extracts and urine from diverse sources were purified by strong or mixed-mode cation exchange and molecularly imprinted polymer SPE cartridges, respectively. Three spiked concentrations (2, 10, and 20 ng/mL) of eight β-agonists in the purified matrices and the different sample sources were analyzed. The results show that for most β-agonists there are significant differences in matrix effects between analyte concentrations or sample sources (P < 0.05), whereas there is no significant difference in matrix effects between different SPE cartridges (P > 0.05). Results from main effects testing indicated that analyte concentration was the main effector.
Co-reporter:Hongbin Guo, Kaiyong Liu, Yahong Liu, Binghu Fang, Min Liu, Limin He, Zhenling Zeng
Journal of Chromatography B 2011 Volume 879(Issue 2) pp:181-185
Publication Date(Web):15 January 2011
DOI:10.1016/j.jchromb.2010.11.041
A simple, sensitive and reproducible high performance liquid chromatographic method was developed for determining valnemulin in feeds. Feed samples were extracted with ethyl acetate under alkaline condition, cleaned up by molecularly imprinted solid-phase extraction, and analyzed by high performance liquid chromatography with ultraviolet detection. The characteristics of the synthesized polymer were evaluated and the loading capacity of the polymer was about 1000 μg analyte/g imprinted polymer. The new procedure for the feed sample cleanup using the prepared polymer cartridge gave higher recoveries and fewer matrix interferences. The assay exhibited a linear dynamic range of 5.0–200 mg kg−1 with the correlation coefficient above 0.9993. Recoveries of valnemulin from feed samples spiked at 5.0, 20 and 50 mg kg−1 ranged between 76.0% and 94.4% with relative standard deviations of less than 9%. The limit of detection for valnemulin in feeds was 1 mg kg−1.
Co-reporter:Yaqiu Zheng, Yahong Liu, Hongbin Guo, Limin He, Binghu Fang, Zhenling Zeng
Analytica Chimica Acta 2011 690(2) pp: 269-274
Publication Date(Web):
DOI:10.1016/j.aca.2011.02.029
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