Co-reporter:Mohammad Reza Almasian, Na Na, Fang Wen, Sichun Zhang and Xinrong Zhang
Analytical Chemistry 2010 Volume 82(Issue 9) pp:3457
Publication Date(Web):April 15, 2010
DOI:10.1021/ac1006975
A novel method has been proposed to enhance efficiency of cataluminescence reaction by applying a plasma-assisted cataluminescence (PA-CTL) system. The obtained results clearly indicated that the PA-CTL system exhibited substantially higher sensitivity for the detection of benzene, toluene, ethylbenzene, and xylenes (BTEX) on the surface of nanosized ZrO2. There are two distinctive advantages in the PA-CTL system; on one hand, the plasma activates the BTEX molecules for the detection, and on the other hand, the working temperature range of the catalytic reaction is lowered with the plasma assistance. A detection limit (LOD = 3σ) of 20 ng mL−1 was achieved for benzene in air samples. Using a graphite electrode in the designed plasma provides an additional opportunity for solid-phase microextraction (SPME) sampling of volatile organic compounds (VOCs) on its surface followed by PA-CTL detection. This ability has been investigated for detection of m-xylene in air samples.
Co-reporter:Ziqing Lin, Mengxia Zhao, Sichun Zhang, Chengdui Yang and Xinrong Zhang
Analyst 2010 vol. 135(Issue 6) pp:1268-1275
Publication Date(Web):16 Mar 2010
DOI:10.1039/B919972A
A simple and fast (<5 s) method for in situ arsenic speciation on solid surfaces has been developed based on desorption electrospray ionization-tandem mass spectrometry (DESI-MS). Arsenic-polluted environmental samples such as animal feed and plant tissues could be directly monitored by DESI-MS. Each arsenic species in this study, including monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB), arsenocholine (AsC), 4-arsanilic acid (p-ASA), 4-hydroxyphenylarsonic acid (4-OH), Nitarsone, Roxarsone and two inorganic arsenic species, arsenate As(V) and arsenite As(III), could be detected by their typical m/z and collision induced dissociation (CID) behavior respectively. By the characteristic information, mixtures of different arsenic species could be detected without any sample preparation and separation process. This method could give absolute detection limits of the arsenic species at ng/mm2 to pg/mm2 level with a best RSD of 5.3% (n = 5). The method could be potentially applied to in situ environmental monitoring of arsenic pollution, especially that caused by arsenic pesticides, animal feed additives, herbicides and wood treatment.
Co-reporter:Rui Liu, Zhi Xing, Yi Lv, Sichun Zhang, Xinrong Zhang
Talanta 2010 Volume 83(Issue 1) pp:48-54
Publication Date(Web):15 November 2010
DOI:10.1016/j.talanta.2010.08.037
A sensitive sandwich type immunoassay has been proposed with the detection by inductively coupled plasma mass spectrometry (ICP-MS) in a single particle mode (time resolved analysis). The signal induced by the flash of ions (197Au+) due to the ionization of single Au-nanoparticle (Au-NP) label in the plasma torch can be measured by the mass spectrometer. The frequency of the transient signals is proportional to the concentration of Au-NPs labels. Characteristics of the signals obtained from Au-NPs of 20, 45 and 80 nm in diameters were discussed. The analytical figures for the determination of Au-labeled IgG using ICP-MS in conventional integral mode and single particle mode were compared in detail. Rabbit-anti-human IgG was used as a model analyte in the sandwich immunoassay. A detection limit (3σ) of 0.1 ng mL−1 was obtained for rabbit-anti-human IgG after immunoreactions, with a linear range of 0.3–10 ng mL−1 and a RSD of 8.1% (2.0 ng mL−1). Finally, the proposed method was successfully applied to spiked rabbit-anti-human IgG samples and rabbit-anti-human serum samples. The method resulted to be a highly sensitive ICP-MS based sandwich type immunoassay.
Co-reporter:Na Na, Sichun Zhang, Xin Wang and Xinrong Zhang
Analytical Chemistry 2009 Volume 81(Issue 6) pp:2092
Publication Date(Web):February 13, 2009
DOI:10.1021/ac802132c
High-throughput screening of catalysts could dramatically improve performance and reduce costs in the discovery and study of various catalysts. Here we report a cataluminescence-based array imaging as a high-throughput screening technique in the combinatorial discovery of active catalysts for CO oxidation. This strategy is based on the fact that the CO oxidation generates cataluminescence emission on the surface of nanomaterials, whose intensity is correlated to the activity of the catalyst. To demonstrate the feasibility of the cataluminescence-based array imaging for high-throughput screening of catalysts, different nanosized metal catalysts supported on TiO2 nanoparticles were prepared. These catalysts include monometallic Au, Pt, and the bimetallic Au−Pt heteroaggregate catalysts, at total metal loadings of 0.5%, 1.0%, and 2.5%, and with atomic ratios of 1:1, 1:2, and 2:1 (Au/Pt). A 4 × 4 array was integrated by depositing these nanosized catalysts onto the ceramic chip, and the brightness of each spot in the image was recorded. The catalytic activities of those catalysts for the CO oxidation were evaluated parallelly by both the cataluminescence imaging and the gas chromatography method. The correlation coefficient is 0.914 for the two techniques, indicating that the cataluminescence imaging technique can be applied for the evaluation of the catalytic activities. Moreover, fast evaluation of multiple catalysts at a series of working temperature can be achieved by this cataluminescene-based array imaging. With the development of nanotechnology as well as the catalyst industry, the cataluminescence-based array imaging will address its importance in the high-throughput screening of catalysts.
Co-reporter:Xiaoxiao Ma, Sichun Zhang, Ziqing Lin, Yueying Liu, Zhi Xing, Chengdui Yang and Xinrong Zhang
Analyst 2009 vol. 134(Issue 9) pp:1863-1867
Publication Date(Web):03 Jul 2009
DOI:10.1039/B907439B
Real-time and in-situ monitoring of ongoing chemical reactions by mass spectrometry was achieved by simply directing the low-temperature plasma (LTP) to the surface of the reaction system for analyte desorption and ionization without any sample pretreatment.
Co-reporter:Yan Zhang, Xiaoxiao Ma, Sichun Zhang, Chengdui Yang, Zheng Ouyang and Xinrong Zhang
Analyst 2009 vol. 134(Issue 1) pp:176-181
Publication Date(Web):25 Nov 2008
DOI:10.1039/B816230A
In this paper, we have constructed a low temperature plasma (LTP) probe using dielectric barrier discharge (DBD) and employed it for the detection of explosives on a variety of substrates under ambient conditions. Upon discharge, a transient, low-temperature non-equilibrium plasma comprising ions, electrons and metastable atoms are generated between the electrodes. Three common explosives, 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-trinitro-1,3,5-triazine (RDX), and pentaerythritol tetranitrate (PETN), were directly desorbed and ionized from solid surfaces, followed by subsequent analysis using the mass spectrometer in the negative ion mode. Limits of detection (LODs) were 500 fg for TNT, 1 pg for RDX, and 500 fg for PETN. The reliability of the method was characterized by a successful analysis of a mixture of the three explosives. The ion source also allowed direct detection of trace explosives on both conductive and non-conductive substrates, thus expanding the applicability of low temperature plasma desorption mass spectrometry.
Co-reporter:Shenghong Hu, Rui Liu, Sichun Zhang, Zhi Huang, Zhi Xing, Xinrong Zhang
Journal of the American Society for Mass Spectrometry 2009 Volume 20(Issue 6) pp:1096-1103
Publication Date(Web):June 2009
DOI:10.1016/j.jasms.2009.02.005
A highly sensitive immunoassay is proposed based on time-resolved inductively coupled plasma mass spectrometry with nanoparticles as tags to antibody. Instead of using traditional integral mode detection, the transient signals induced by the flash of ions in the plasma torch from the ionization of nanoparticles tagged on antibody were recorded in a time-resolved mode. Since, under certain conditions, the frequency of transient signals is directly correlated to the concentration of nanoparticle tags, the concentration of nanoparticle-tagged antibodies can be quantified by the frequency of transient signals. With the present instrument setup, gold nanoparticle (Au-NP) tags, as small as about 15 nm in diameter, can be detected. This protocol is evaluated for a competitive immunoassay and the linear range for α-fetoprotein is 0.016–6.8 μg/L (between 20 and 80% inhibition). The limit of quantification is 0.016 μg/L (20% inhibition, IC20) with a relative standard deviation of 4.2% (20% inhibition, 4 replicates) for α-fetoprotein. The present strategy provides a sensitive readout method for nanoparticle tags, which is quite promising for numerous applications in immunoassay, DNA hybridization, and other biological analyses.A highly sensitive immunoassay is proposed based on time-resolved inductively coupled plasma mass spectrometry with gold nanoparticles as tags to antibody.Figure optionsDownload full-size imageDownload high-quality image (121 K)Download as PowerPoint slide
Co-reporter:Yanyan Lu, Wenjun Wang, Zhi Xing, Shidong Wang, Po Cao, Sichun Zhang, Xinrong Zhang
Talanta 2009 Volume 78(Issue 3) pp:869-873
Publication Date(Web):15 May 2009
DOI:10.1016/j.talanta.2008.12.065
A sandwich-type immunoassay linked with inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the detection of anti-erythropoietin antibodies (anti-EPO Abs). Recombinant human erythropoietin (rhEPO) was immobilized on the solid phase to capture anti-rhEPO Abs specifically. After the immunoreactions with Au-labeled goat-anti-rabbit IgG, a diluted HNO3 (2%) was used to dissociate Au nanoparticles which was then introduced to the ICP-MS for measurements. Under the optimized conditions, the calibration graph for anti-EPO Abs was linear in the range of 35.6–500 ng mL−1 with a detection limit of 10.7 ng mL−1 (3σ, n = 9). The relative standard deviation (R.S.D.) for three replicate measurements of 30.9 ng mL−1 of anti-EPO Abs was 8.43%. The recoveries of anti-EPO Abs in sera at the spiking level of 50, 100, 150, 200 and 400 ng mL−1 were 99.2%, 101.5%, 95.0%, 94.0% and 102.9%, respectively. For the real sample analysis, 26 samples from healthy people and 53 samples from patients with rhEPO treatments were studied. One sample from patients showed significantly higher anti-EPO Abs from other samples, indicating a possibility of immune response of this patient.
Co-reporter:Fang Wen, Sichun Zhang, Na Na, Yayan Wu, Xinrong Zhang
Sensors and Actuators B: Chemical 2009 Volume 141(Issue 1) pp:168-173
Publication Date(Web):18 August 2009
DOI:10.1016/j.snb.2009.06.014
An optical sensor for ethanol has been proposed by trapping the analytes on sensing nanomaterials at room temperature and detecting them in situ by recording the cataluminescence (CTL) signals with fast elevated temperature. Sensing nanomaterials of ZrO2 were directly deposited on heating filament which enables the temperature programming for trapping and detecting the interested analytes. The miniaturized sensing unit has low incandescent radiation so as to provide the high signal-to-noise ratio. Under the optimized conditions, the linear range for the determination of ethanol vapor is 1.0 × 10−3 to 1.0 mg L−1. A detection limit (S/N = 3) is 2.0 × 10−4 mg L−1 (0.1 ppm), which is improved about 3000-fold for ethanol compared with previous CTL sensors. The relative standard deviation (RSD) is 1.2% (n = 7) for ethanol samples at a concentration of 0.08 mg L−1. The stability was demonstrated by continuous reaction with ethanol for 120 h. This sensor has been applied to monitor the ethanol concentration in human expired gas after drinking, and the results agreed well with the reference values. This miniature ethanol sensor offers higher sensitivity, faster response and lower power consumption, which make it very promising in developing hand-hold sensing device for field detection.
Co-reporter:Yueying Liu;Ziqing Lin;Sichun Zhang
Analytical and Bioanalytical Chemistry 2009 Volume 395( Issue 3) pp:591-599
Publication Date(Web):2009 October
DOI:10.1007/s00216-009-2947-x
A high-throughput method for rapid screening of active ingredients in drugs has been developed with mass spectrometry coupled to a low-temperature plasma (LTP) probe ion source. Without sample preparation or pretreatment, the active ingredients of 11 types of commercial pharmaceuticals, including hormones, antipyretic analgesics, cardiovascular, digestant, neuro-psychotherapeutic, diuretic, antithyroid, sulfa anti-inflammatory, antiparastic, sedative-hypnotics, and antibacterial, were directly desorbed/ionized and detected by a linear ion trap mass spectrometry (MS). The structures of these ingredients were elucidated by tandem MS. The analysis of 18 methyltestosterone tablets could be accomplished within 1.9 min, which allows fast detection with a speed of approximate 600 samples within 1 h. This work demonstrated that LTP probe ion source combined with MS is a high-throughput method for screening of pharmaceuticals and potentially applied to on-line quality control in pharmaceutical industry.
Co-reporter:Wenjun Wang;Yanyan Lu;Sichun Zhang;Shidong Wang;Po Cao;Yaping Tian
Luminescence 2009 Volume 24( Issue 1) pp:55-61
Publication Date(Web):
DOI:10.1002/bio.1065
Abstract
Measuring low amounts of anti-erythropoietin antibodies (anti-EPO Abs) is important to evaluate the therapeutic safety of recombinant human erythropoietin (rhEPO). In this work, a simple, sensitive and high-throughput chemiluminescent (CL) imaging assay was developed for the detection of anti-EPO Abs in human sera. The influence of several physicochemical parameters, such as coating conditions, incubation time, detergent concentration and exposure time, were investigated. A calibration curve was established and the range of quantitative detection was 0.12–13.91 ng/mL. The limit of detection (LOD, 3σ) for the CL-imaging assay was 0.033 ng/mL. Compared to conventional colorimetric enzyme-linked immunosorbent assay (ELISA), the LOD of the CL-imaging assay is 50-fold lower. The recoveries of anti-EPO Abs in the fortified serum were in the range 87.1–116.9% using the present method, which highlighted the validity of the CL-imaging assay system to accurately determine the anti-EPO Abs in serum samples. CL-imaging assay was used to evaluate the presence of anti-EPO Abs in serum samples obtained from chronic renal failure (CRF) patients treated with rhEPO. Contrary to what was expected, the sera from CRF patients did not contain anti-EPO Abs. Copyright © 2008 John Wiley & Sons, Ltd.
Co-reporter:Xiaoxiao Ma, Mengxia Zhao, Ziqing Lin, Sichun Zhang, Chengdui Yang and Xinrong Zhang
Analytical Chemistry 2008 Volume 80(Issue 15) pp:6131
Publication Date(Web):June 28, 2008
DOI:10.1021/ac800803x
A simple and easy-to-build high-throughput analysis system was constructed. The system consisted of three major components: (1) a multichannel device with 16 parallel capillaries, (2) a desorption electrospray ionization (DESI) source, and (3) a linear ion trap mass spectrometer. When analyses were performed, the multichannel device was moved horizontally on a translation stage controlled by a step motor. Our design expands the functions of DESI, in which the liquid sample in capillary was driven out by the nebulizing gas, ionized, and then transferred to a mass spectrometer. To assess the high-throughput performance of the system, 5 mg/L 1,3-diethyl-1,3-diphenylurea (DDU) solution and 10 mg/L angiotensin I solution were alternatively loaded into the reservoirs and capillaries in the multichannel device. Results indicated that analyses of the all the samples in 16 capillaries were completed within 1.6 min, which means a throughput of 600 samples/h. Reactive DESI experiment was also successfully performed with this system to show the feasibility of online derivatization. The relative standard deviations for a single capillary and five identical capillaries were 7.6 (n = 16) and 12.3%, respectively. Linear relative abundance response was achieved for DDU (r=0.9971).
Co-reporter:Zhenli Zhu, Jixin Liu, Sichun Zhang, Xing Na, Xinrong Zhang
Analytica Chimica Acta 2008 Volume 607(Issue 2) pp:136-141
Publication Date(Web):28 January 2008
DOI:10.1016/j.aca.2007.11.041
A new atomizer based on atmospheric pressure dielectric barrier discharge (DBD) plasma was specially designed for atomic fluorescence spectrometry (AFS) in order to be applied to the measurement of arsenic. The characteristics of the DBD atomizer and the effects of different parameters (power, discharge gas, gas flow rate, and KBH4 concentration) were discussed in the paper. The DBD atomizer shows the following features: (1) low operation temperature (between 44 and 70 °C, depending on the operation conditions); (2) low power consumption; (3) operation at atmospheric pressure. The detection limit of As(III) using hydride generation (HG) with the proposed DBD-AFS was 0.04 μg L−1. The analytical results obtained by the present method for total arsenic in reference materials, orchard leaves (SRM 1571) and water samples GBW(E) 080390, agree well with the certified values. The present HG-DBD-AFS is more sensitive and reliable for the determination of arsenic. It is a very promising technique allowing for field arsenic analysis based on atomic spectrometry.
Co-reporter:Zhenli Zhu, Jixin Liu, Sichun Zhang, Xing Na, Xinrong Zhang
Spectrochimica Acta Part B: Atomic Spectroscopy 2008 Volume 63(Issue 3) pp:431-436
Publication Date(Web):March 2008
DOI:10.1016/j.sab.2007.12.008
A flameless atomizer for atomic fluorescence spectrometry (AFS), based on an atmospheric pressure dielectric barrier discharge, has been developed for the atomization of hydride-forming elements, such as Se, Sb and Pb. The atomizer (8 mm o.d, 35 mm length) was operated at a power less than 50 W. The discharge was sustained with argon at the flow rate of 0.85 L min− 1 after optimization. The characteristics of the atomizer and the effects of different parameters (power, gas flow rate, and KBH4 concentration) are investigated. The most attractive feature of this atomizer is its low operation temperature (~ 52 °C, detected at the outlet of the atomizer by a thermocouple), allowing both the radiation source and the detector to be placed in close proximity with the atomizer. The analytical performance of the atomizer has been evaluated, and detection limits for Se, Sb and Pb obtained with the present technique were 0.08, 0.11 and 0.27 μg L− 1, respectively. The accuracy of the system was verified by the determination of Se, Sb and Pb in reference material of spinage GBW 10015. The concentrations of Se, Sb, and Pb determined by the present technique agreed well with the reference values (Se: 92 ± 24 mg kg− 1, Sb: 43 ± 14 mg kg− 1, Pb: 11.1 ± 0.9 mg kg− 1). This detector is very promising for field elements detection with portable AFS.
Co-reporter:Na Na;Mengxia Zhao;Sichun Zhang
Journal of The American Society for Mass Spectrometry 2007 Volume 18( Issue 10) pp:1859-1862
Publication Date(Web):2007 October
DOI:10.1016/j.jasms.2007.07.027
A new ion source based on dielectric barrier discharge was developed as an alternative ionization source for ambient mass spectrometry. The dielectric barrier discharge ionization source, termed as DBDI herein, was composed of a copper sheet electrode, a discharge electrode, and a piece of glass slide in between as dielectric barrier as well as sample plate. Stable low-temperature plasma was formed between the tip of the discharge electrode and the surface of glass slide when an alternating voltage was applied between the electrodes. Analytes deposited on the surface of the glass slide were desorbed and ionized by the plasma and the ions were introduced to the mass spectrometer for mass analysis. The capability of this new ambient ion source was demonstrated with the analysis of 20 amino acids, which were deposited on the glass slide separately. Protonated molecular ions of [M+H]+ were observed for all the amino acids except for L-arginine. This ion source was also used for a rapid discrimination of L-valine, L-proline, L-serine and L-alanine from their mixture. The limit of detection was 3.5 pmol for L-alanine using single-ion-monitoring (SIM). Relative standard deviation (RSD) was 5.78% for 17.5 nmol of L-alanine (n=5). With the advantages of small size, simple configuration and ease operation at ambient conditions, the dielectric barrier discharge ion source would potentially be coupled to portable mass spectrometers.
Co-reporter:Qun Zhou, Su-Qin Sun, Lu Yu, Chang-Hua Xu, Isao Noda, Xin-Rong Zhang
Journal of Molecular Structure 2006 Volume 799(1–3) pp:77-84
Publication Date(Web):6 November 2006
DOI:10.1016/j.molstruc.2006.03.025
Infrared (IR) spectroscopy and two-dimensional (2D) correlation IR spectroscopy are shown to offer some information about stability and shelf life of milk powders without separation and extraction of individual components in this paper. Temperature has been chosen as the perturbation to monitor the infrared behavior of various milk powders, namely, whole milk powder (WMP), sweet whole milk powder (Sweet WMP), low-fat milk powder (LFMP), and skim milk powder (SMP). The sequential order of changes in protein, fat and carbohydrates (mainly lactose) in milk powders is studied for the first time. The protein changes before the sucrose in WMP, whereas the sucrose changes before the protein in Sweet WMP under temperature perturbation. It is also found that in SMP, carbohydrate changes prior to protein whereas in LFMP and WMP protein changes first as the temperature is increased. The conclusion can provide some useful reference to understand the thermal stability of milk powders.
Co-reporter:Huaqiang Cao ;Guozhi Wang;Lei Zhang;Yu Liang;Sichun Zhang Dr.
ChemPhysChem 2006 Volume 7(Issue 9) pp:1897-1901
Publication Date(Web):1 AUG 2006
DOI:10.1002/cphc.200600130
Unusual magnetic behavior of α-Fe2O3: Rice- (a) and cube-shaped (b) single-crystalline α-Fe2O3 nanostructures (see microstructure images) are obtained by a new hydrothermal reaction route. Different magnetic anisotropies are observed for the rice- and cube-shaped α-Fe2O3 nanocrystals. This behavior offers possibilities for technological applications of α-Fe2O3 with magnetic properties tailored by shape-controlled synthesis.
Co-reporter:Z. Sun;H. Yuan;Z. Liu;B. Han;X. Zhang
Advanced Materials 2005 Volume 17(Issue 24) pp:
Publication Date(Web):3 NOV 2005
DOI:10.1002/adma.200501562
α-Fe2O3 nanotubes that can be used as chemical sensors (see Figure) are fabricated by a novel carbon nanotube (CNT) templated synthesis. CNTs are coated with a continuous layer of Fe2O3 nanoparticles by the decomposition of Fe(NO3)3 in a supercritical CO2/ethanol solution. Subsequent removal of the CNTs gives α-Fe2O3 nanotubes that are highly sensitive to H2S, which makes them attractive materials for chemiluminescent H2S sensors.
Co-reporter:Zhenyu Zhang, Ke Xu, Willy R.G. Baeyens, Xinrong Zhang
Analytica Chimica Acta 2005 Volume 535(1–2) pp:145-152
Publication Date(Web):11 April 2005
DOI:10.1016/j.aca.2004.12.025
When reductive gases pass over the surface of nanosized catalysts, a kind of chemiluminescence named cataluminescence (CTL) can be generated due to the production of excited intermediates. Here we report the observation of an energy transfer process between excited intermediates and the nanosized catalysts. The CTL is quenched when introducing Ho3+, Co2+ and Cu2+ into the catalyst, while new intensive CTL peaks appear when the catalyst is doped with Eu3+ or Tb3+. Further study indicates that the new CTL peak on Eu3+- or Tb3+-doped catalyst originates from the luminescence of the doped ions, excited by the energy transferred from excited intermediates produced during the reaction. Based on this novel energy-transfer CTL (ETCTL), an ethanol sensor is developed with Eu3+-doped nanosized ZrO2 that is linear to ethanol concentrations from 45 to 550 ppm, with the whole linear range lower than the lower limit of the previous CTL sensor. The ETCTL from Eu3+-doped in nanosized ZrO2 shows 72 times higher sensitivity than the CTL from excited intermediates in the sensor. High selectivity and stability are also obtained for this sensor. The results also indicate that the main factor limiting the sensitivity of CTL sensor on pure catalyst may be the inevitable energy quenching of excited intermediates with the catalyst, which is artfully utilized in the present work by the introduction of Eu3+ that effectively absorbs this part of energy and transfers it into light energy.
Co-reporter:Zhenli Zhu;Rui Zhao;Yi Lv;Xianshun Xu
Luminescence 2005 Volume 20(Issue 4‐5) pp:298-302
Publication Date(Web):31 AUG 2005
DOI:10.1002/bio.860
A novel flow injection chemiluminescence method for the determination of orciprenaline was developed. The method is based on the chemiluminescence (CL) reaction of orciprenaline with potassium ferricyanide in sodium hydroxide medium, sensitized by the fluorescent dye rhodamine 6G. The proposed procedure allows quantitation of orciprenaline in the concentration range 0.01–1.2 µg/mL, with a detection limit of 7.2 × 10−3 µg/mL. The relative standard deviation (RSD) is 2.7% for 0.1 µg/mL orciprenaline (n = 9). The sampling frequency was calculated at ∼120/h. The method was successfully applied to the determination of orciprenaline in pharmaceutical preparations. A brief discussion on the possible CL reaction mechanism is presented. Copyright © 2005 John Wiley & Sons, Ltd.
Co-reporter:Zhenyu Zhang, Ke Xu, Zhi Xing, Xinrong Zhang
Talanta 2005 Volume 65(Issue 4) pp:913-917
Publication Date(Web):28 February 2005
DOI:10.1016/j.talanta.2004.08.014
The development of a catalytic chemiluminescent trimethylamine (TMA) sensor is demonstrated in the present paper. Intensive chemiluminescence (CL) is detected when TMA is introduced over the surface of nanosized catalysts and subsequently catalytically oxidized by O2 from the air, and four catalysts are investigated with the strongest CL intensity obtained on nanosized Y2O3. This effect is utilized to develop a novel nanosized Y2O3-based catalytic CL sensor for TMA which under optimal conditions exhibits a wide linear range of 60–42,000 ppm and a detection limit of 10 ppm. An attractive advantage of this novel CL sensor is its high selectivity to TMA with negligible responses to many other gases such as NH3 and organic vapors. This CL sensor has a short response time of less than 3 s, and shows good stability when examined by continual introduction of TMA into the sensor for 96 h. The applicability of this sensor to actual fish samples is also demonstrated in the paper.
Co-reporter:Xiaoan Cao
Luminescence 2005 Volume 20(Issue 4‐5) pp:243-250
Publication Date(Web):31 AUG 2005
DOI:10.1002/bio.859
In this paper, we propose a model of a sensor array system, which consists of three cataluminescence sensors based on nanosized SrCO3, γ-Al2O3 and BaCO3 as catalysts, for quantitative analysis of the explosive gases of propane, n-butane and iso-butane in a mixture. Six linear regression equations of the cataluminescence intensity vs. the gas concentrations in the range 2000–10 000 ppm were established from the sensor array system at two working temperatures, as the explosive gases show different sensitivity to the three sensors. The least squares method was employed for solving the simultaneous equations and quantifying the concentrations of the three components. The detection limits (3σ) of propane, n-butane and iso-butane on SrCO3, γ-Al2O3 and BaCO3 sensors are 50, 40 and 20 ppm, 80, 60 and 40 ppm, and 20, 10 and 5 ppm, respectively. The concentrations of two artificial samples containing the tertiary mixture were analysed with satisfactory results. Copyright © 2005 John Wiley & Sons, Ltd.
Co-reporter:Guohong Liu, Jinglin Wang, Yongfa Zhu and Xinrong Zhang
Physical Chemistry Chemical Physics 2004 vol. 6(Issue 5) pp:985-991
Publication Date(Web):27 Jan 2004
DOI:10.1039/B312082A
The reaction between nanometer TiO2 and CCl4 in the presence of oxygen has been studied in order to investigate the potential of nanometer TiO2 as a destructive reagent for chlorinated hydrocarbons. Two kinds of nanometer TiO2 of different size were synthesized. The properties of the destructive adsorption of CCl4 over nanometer TiO2 of about 40 nm in size were compared with that over nanometer TiO2 of about 80 nm in size. The reactivity toward CCl4 of nanometer TiO2 of about 40 nm in size was remarkably higher than that of nanometer TiO2 of about 80 nm in size. The products produced included CO2, COCl2, Cl2, titanium oxychloride, TiCl4, carbon, CO and HCl. HCl was a major gaseous product. Hydrogen of HCl came from traces of water in the carrier gas and surface OH groups of TiO2. The formation of TiCl4 made the interaction surface renew so that CCl4 could further interact with the bulk of the particles. TiO2 was regenerated through the exchange of chlorine with oxygen at 550°C in the carrier gas so that larger quantities of CCl4 are decomposed over nanometer TiO2 in the presence of oxygen. A mechanism has been proposed for the destructive adsorption and desorption of CCl4 over nanometer TiO2 in the presence of oxygen.
Co-reporter:Xiaoan Cao, Zhenyu Zhang, Xinrong Zhang
Sensors and Actuators B: Chemical 2004 Volume 99(Issue 1) pp:30-35
Publication Date(Web):15 April 2004
DOI:10.1016/j.snb.2003.09.003
A cataluminescence (CTL) sensor using nanosized BaCO3 as sensing material for the determination of trace acetaldehyde in air samples was developed. The proposed sensor showed high sensitivity and selectivity to acetaldehyde at optimal temperature of 225 °C. Quantitative analysis was performed at a wavelength of 555 nm. The linear range of CTL intensity versus concentration of acetaldehyde is 2–2000 ppm (r=0.9981, n=8), with a detection limit of 0.5 ppm (signal-to-noise ratio = 3). None or only very low levels of significant interference were observed while the foreign substances such as cyclohexane, n-hexane, carbon tetrachloride, ammonia, methylbenzene, chloroform, benzene, formaldehyde, ethanol and carbon dioxide are passing through the sensor. There was no interference due to the 20 000 ppm water vapor in the determination of 200 ppm acetaldehyde vapor. The stability of the sensor was tested by continuous reaction with acetaldehyde for 100 h. The response time of the sensor is less than 50 s.
Co-reporter:Jinjun Shi, Ruoxue Yan, Yongfa Zhu, Xinrong Zhang
Talanta 2003 Volume 61(Issue 2) pp:157-164
Publication Date(Web):17 October 2003
DOI:10.1016/S0039-9140(03)00240-6
Combination of a novel NH3 converter based on nanosized materials with chemiluminescence (CL) detector for the determination of NH3 gas was demonstrated in this paper. NH3 gas is oxidized on different nanosized catalysts to produce NOx, which can react with luminol to generate CL emission. Eight nanosized materials were investigated as catalyst, and CL was detected from seven of them. The nanosized LaCoO3 was chosen as the catalyst for preparing the converter because of its higher activity than others. Under the optimized conditions, the linear range of CL intensity versus concentration of NH3 gas is 0.04–10 ppm (r=0.9951, n=14) with the detection limit of 0.014 ppm. The method offers advantages of long lifetime of the converter, fast response and high selectivity to NH3. There was no response while the foreign substances, such as hydrogen, oxygen, nitrogen, formaldehyde, acetone and gasoline passing through the CL detection system, and the interference of CCl4, ethanol, ethylene and toluene was insignificant.
Co-reporter:Zhenyu Zhang, Chao Zhang and Xinrong Zhang
Analyst 2002 vol. 127(Issue 6) pp:792-796
Publication Date(Web):09 May 2002
DOI:10.1039/B202223K
Chemiluminescence was observed on introducing ethanol vapor to the surface of nanosized ZrO2 and this effect could be utilized to design a sensor for trace ethanol detection. The term cataluminescence (CTL) was used to describe this kind of chemiluminescence because the luminescence is generated by the catalytic oxidation of organic vapors on the solid surface. The proposed sensor showed high sensitivity to ethanol at 195 °C. The stability of the gas sensor was demonstrated by continuous reaction with ethanol for 100 h. Quantitative analysis was performed at an optimum wavelength of 460 ± 10 nm. The chemiluminescence intensity was proportional to the concentration of ethanol from 1.6 to 160 μg ml−1, with a detection limit of 0.6 μg ml−1 (signal-to-noise ratio = 3:1). The mechanism of the chemiluminescence reaction is discussed and the results show that one of the possible luminescent intermediates is acetaldehyde.
The chemiluminescence on nanosized ZrO2 observed in this work demonstrates the possibility of developing new nanomaterials for low-temperature cataluminescence detection.
Co-reporter:Chao Zhang, Fengbo Wu and Xinrong Zhang
Journal of Analytical Atomic Spectrometry 2002 vol. 17(Issue 10) pp:1304-1307
Publication Date(Web):27 Aug 2002
DOI:10.1039/B205623B
To further expand the range of analytes that can be detected by using ICP-MS coupled with bioanalytical methods, we have employed a new separation system based on the highly active surface streptavidin and biotinylated monoclonal antibody (McAb) in a competitive immunoassay followed by ICP-MS detection. Specifically, we have demonstrated its application for the determination of total thyroxine (T4) in human serum using Eu3+ as a label. In this method, streptavidin immobilized to the pre-coated bovine serum albumin (BSA)-biotin on the microwells showed a significantly higher binding capacity for the biotinylated anti-T4 monoclonal antibody. Total T4 was quantified by measuring the Eu3+ intensity with ICP-MS after using 1% HNO3 to extract Eu3+ from the bound fraction of the immunocomplex. The detection limit was 7.4 ng mL−1 with a sample volume of 25 µL. Total T4 values obtained by this procedure agreed well with those obtained by a chemiluminescent immunoassay method. Both inter- and intra-assay precisions were below 10%. The results indicate that a general competitive ICP-MS-based immunoassay scheme may be possible.
Co-reporter:Fengzhen Yang, Chao Zhang, Willy R.G Baeyens, Xinrong Zhang
Journal of Pharmaceutical and Biomedical Analysis 2002 Volume 30(Issue 3) pp:473-478
Publication Date(Web):15 October 2002
DOI:10.1016/S0731-7085(02)00096-1
Strong chemiluminescence emission has been observed by mixing alkaline hydrolytic products of ethamsylate with Tween 80 in acidic rhodamine 6G solution. This phenomenon has been utilized to design a flow-injection chemiluminescence method for the determination of ethamsylate in a pharmaceutical preparation. Under the optimum conditions, the proposed procedure has a linear range between 0.05 and 2.0 μg ml−1, with a detection limit of 0.02 μg ml−1 for ethamsylate. The method was applied to the determination of ethamsylate in pharmaceutical preparations. The possible mechanism of this chemiluminescence reaction was proposed.
Co-reporter:Zhiming Rao, Xinrong Zhang, Willy R.G Baeyens
Talanta 2002 Volume 57(Issue 5) pp:993-998
Publication Date(Web):3 July 2002
DOI:10.1016/S0039-9140(02)00143-1
A new chemiluminescence (CL) flow-injection method is proposed for the determination of 1,3-dichloro-5,5-dimethylhydantoin (DDH). The method is based on the chemiluminescent reaction of DDH and luminol–H2O2 in an alkaline medium (pH 12.0–12.5). The concentration of the analyte shows a good linear relationship with the produced luminescence intensity in the range of 3.0×10−8 to 8.0×10−6 mol l−1. The detection limit of the proposed method is 1.0×10−8 mol l−1 and the relative standard deviation (R.S.D.) is 4.7% (n=5) at 5.0×10−7 mol l−1. This method was successfully applied to the determination of trace amounts of this disinfectant in water samples obtained from five different swimming pools. Satisfying recovery values were also obtained.
Co-reporter:Jianning Wang, Minqiang Lu, Fengzhen Yang, Xinrong Zhang, Willy R.G Baeyens, A.M Garcı́a Campaña
Analytica Chimica Acta 2001 Volume 428(Issue 2) pp:173-181
Publication Date(Web):9 February 2001
DOI:10.1016/S0003-2670(00)01247-2
An on-line method was developed for the real-time detection of nitric oxide (NO) release in rat brain in vivo following traumatic injury by coupling microdialysis sampling to flow-injection chemiluminescence (CL) detection. The NO released from rat cerebellum was detected based on the CL reaction of luminol and H2O2 with a detection limit of 1 nmol l−1. The perfusate flow was set at 5 μl min−1 in order to minimize NO loss before reaching CL detector. With this flow rate, about 5 s was required for the solution to pass through the membrane of microdialysis probe to the detector due to the dead volume of the probe and CL cell. It was observed that the efficiency of NO penetrated from rat cerebellum into perfusate stream increased along with decrease of perfusate flow rate. The maximum efficiency of 20% could be achieved at the flow rate of 5 μl min−1 with carefully home-made microdialysis probe. The developed method was applied to the study of the production of NO in rat cerebellum following the traumatic brain injury. The results indicated that the NO increased dramatically following traumatic brain injury and was inhibited after the injection of inhibitors such as l-arginine.
Co-reporter:Yan Tong, Zhuping Wu, Chengdui Yang, Jianyuan Yu, Xinrong Zhang, Shijie Yang, Xinyuan Deng, Yucai Xu and Yuxiu Wen
Analyst 2001 vol. 126(Issue 4) pp:480-484
Publication Date(Web):02 Mar 2001
DOI:10.1039/B010183O
A novel method for determination of diphenylamine (DPA) and its nitrated derivatives, which are considered as characteristic components in smokeless powder and gunshot residues, is described. A tandem mass spectrometric method is established and mass spectrometer parameters optimized for each compound to obtain higher sensitivity. Under optimum conditions, quantitative analysis was carried out. The linear ranges are 5.0–200.0, 2.0–200.0 and 5.0–250.0 ng ml−1 and the detection limits are 1.0, 0.5 and 2.5 ng ml−1 for diphenylamine (DPA), N-NO-diphenylamine (N-NO-DPA) and 4-NO2-diphenylamine (4-NO2-DPA), respectively. Intra-assay and inter-assay precision and accuracy of analysis of these three samples were investigated. Based on the regression lines obtained above, smokeless samples were analyzed. It was found that there are 0.952% DPA, 0.384% N-NO-DPA and 0.128% 4-NO2-DPA in smokeless powder. Recovery tests showed that using cotton swabs, 80.3 ± 4.9% DPA, 79.6 ± 3.1% N-NO-DPA and 83.1 ± 5.4% 4-NO2-DPA could be recovered from human hands.
Co-reporter:Chao Zhang, Fengbo Wu, Yanyan Zhang, Xin Wang and Xinrong Zhang
Journal of Analytical Atomic Spectrometry 2001 vol. 16(Issue 12) pp:1393-1396
Publication Date(Web):30 Oct 2001
DOI:10.1039/B106387C
The novel coupling method based on the hyphenation of immunoreaction with ICP-MS was developed and applied to the determination of thyroid-stimulating hormone (TSH) in human serum. In this system, TSH was firstly captured by anti-TSH monoclonal antibodies immobilized on a solid support. Biotinylated anti-TSH monoclonal antibodies and Eu3+-labelled streptavidin were then added to form the complex, captured antibody–TSH–biotinylated anti-TSH antibody–Eu3+-labelled streptavidin. After unbound reactants were washed away, Eu3+ bound to the complex was extracted by 1% HNO3 and measured by ICP-MS. The Eu signal was directly proportional to the serum TSH concentration. The limit of detection was 0.5 mIU L−1 and the assay was linear up to 170 mIU L−1. The within-run (n = 6) and between-run (n = 6)
relative standard deviations (RSD) for low, medium and high concentration standards did not exceed 10%. The TSH results obtained by this procedure correlated well with those obtained by radioimmunoassay (r2 = 0.9639).
Co-reporter:Jianning Wang, Chao Zhang, Haixia Wang, Fengzhen Yang, Xinrong Zhang
Talanta 2001 Volume 54(Issue 6) pp:1185-1193
Publication Date(Web):6 July 2001
DOI:10.1016/S0039-9140(01)00388-5
A simple, fast chemiluminescence (CL) flow-injection method based on the reaction of luminol with H2O2 in the presence of a cationic surfactant (cyltrimethylammonium bromide, CTMAB) has been described for the direct determination of dichlorvos pesticide (DDVP). Under the optimal conditions, the CL intensity was linear to the DDVP concentration in the range of 0.02–3.1 μg ml−1 (r=0.9998, n=10). The relative standard deviation was 3.4% at 0.35 μg ml−1 (n=10), with a detection limit (3σ) of 0.008 μg ml−1 DDVP. The possible reaction mechanism was also discussed. This method has been successfully applied to the determination of trace DDVP residue in vegetable sample and results have been compared with that of the UV method.
Co-reporter:Yi Rao, Yan Tong, Xinrong Zhang, Guoan Luo, Willy R.G Baeyens
Analytica Chimica Acta 2000 Volume 416(Issue 2) pp:227-230
Publication Date(Web):10 July 2000
DOI:10.1016/S0003-2670(00)00904-1
A new chemiluminescence (CL) flow-injection method was proposed for the determination of ofloxacin in pharmaceuticals in the range 0.04−4 μg ml−1 with a detection limit of 0.016 μg ml−1 and a relative standard derivation (R.S.D.) of 2.2% at 0.4 μg ml−1 (n=10). The method is based on the CL reaction of cerium(IV) with sulphite sensitized by ofloxacin. The established procedure could be applied to the determination of ofloxacin in tablet, capsule and injection in agreement with the results obtained by using reported methods.
Co-reporter:Y. Rao, Xinrong Zhang, Guoan Luo, Willy R.G. Baeyens
Analytica Chimica Acta 1999 Volume 396(2–3) pp:273-277
Publication Date(Web):20 September 1999
DOI:10.1016/S0003-2670(99)00425-0
A flow-injection method is described for the determination of furosemide in the range 1.0–50.0 μmol l−1, with a detection limit of 0.22 μmol l−1 and a relative standard deviation of 2.1% at 10 μmol l−1 (n = 10). The method is based on the chemiluminescence reaction of furosemide with cerium (IV) in sulphuric acid, sensitized by rhodamine 6G. By applying the method to tablets and injection solutions, it was found that the present method is relatively free from interference and tolerable to turbid solutions.
Co-reporter:Zhi Huang, Jun Li, Sichun Zhang, Xinrong Zhang
Toxicology Letters (1 June 2009) Volume 187(Issue 2) pp:69-76
Publication Date(Web):1 June 2009
DOI:10.1016/j.toxlet.2009.01.024
At least 25 selenoproteins in humans and 24 homologues in rodents have been identified. They play important roles in antioxidation, redox regulation and detoxification. The modulation of the expression of selenoproteins by inorganic arsenic (iAs) exposure may highlight the molecular mechanism for the arsenic toxicity. To investigate the effects of iAs exposure on the expression of selenoproteins, we determined how addition of iAs to culture medium affected all known selenoproteins in the mouse embryonic stem (ES) cells. Separated groups of ES cells were treated with arsenite (iAsIII) (0.25–0.5 μM), arsenate (iAsV) (1.0–2.0 μM) and co-treatment with sodium selenite (SeIV) (0.5 μM). The mRNA levels of all selenoproteins were detected by real time quantitative PCR. The up-regulated selenoproteins were confirmed by immunoblotting analysis and enzymatic activity detection. Results showed that CGR8 cells treated with iAsIII (0.25–0.5 μM) and iAsV (2.0 μM) displayed significant increases of cellular reactive oxygen species (ROS) generation and nuclear accumulation of the transcription factor NF-E2-related factor 2 (Nrf2). Treatments of iAsIII (0.5 μM) or iAsV (2.0 μM) for 24 h caused significant increases in the expression of the antioxidant selenoproteins (Gpx1, Gpx4, and Tr1), whereas led to significant decreases in the mRNA levels of selenoprotein H and some endoplasmic reticulum (ER) located selenoproteins (15-Sep, SelK, SelM, and SelS). Additionally, supplement of SeIV (0.5 μM) could restore most of the down-regulated selenoproteins. These results suggested that iAs exposure modulated not only the antioxidant selenoproteins but also the ER stress associated selenoproteins. Further studies are required to clarify whether these modulated selenoproteins genes are targets for selenium supplement in the defense against the toxicity of iAs.
![3H-Indolium, 2-[5-[1-[6-[(2,5-dioxo-1-pyrrolidinyl)oxy]-6-oxohexyl]-1,3-dihydro-3,3-dimethyl-5-sulfo-2H-indol-2-ylidene]-1,3-pentadien-1-yl]-1-ethyl-3,3-](/data/chemimg/105700/146368-14-1.png)
![3H-Indolium, 2-[5-[1-[6-[(2,5-dioxo-1-pyrrolidinyl)oxy]-6-oxohexyl]-1,3-dihydro-3,3-dimethyl-5-sulfo-2H-indol-2-ylidene]-1,3-pentadien-1-yl]-1-ethyl-3,3-](/data/chemimg/105700/146368-14-1_b.png)
![3,5,8-Trioxa-4-phosphahexacos-17-en-1-aminium,4-hydroxy-N,N,N-trimethyl-9-oxo-7-[[(1-oxohexadecyl)oxy]methyl]-, inner salt,4-oxide, (7R,17Z)-](http://img.cochemist.com/ccimg/26900/26853-31-6.png)
![3,5,8-Trioxa-4-phosphahexacos-17-en-1-aminium,4-hydroxy-N,N,N-trimethyl-9-oxo-7-[[(1-oxohexadecyl)oxy]methyl]-, inner salt,4-oxide, (7R,17Z)-](http://img.cochemist.com/ccimg/26900/26853-31-6_b.png)
![Benzenamine, 4-[1-(phenylmethyl)-1H-1,2,3-triazol-4-yl]-](/data/chemimg/2752400/104951-46-4.png)
![Benzenamine, 4-[1-(phenylmethyl)-1H-1,2,3-triazol-4-yl]-](/data/chemimg/2752400/104951-46-4_b.png)
![3,4-Pyrrolidinediol,2-[(4-methoxyphenyl)methyl]-, 3-acetate, (2R,3S,4S)-](http://img.cochemist.com/ccimg/22900/22862-76-6.png)
![3,4-Pyrrolidinediol,2-[(4-methoxyphenyl)methyl]-, 3-acetate, (2R,3S,4S)-](http://img.cochemist.com/ccimg/22900/22862-76-6_b.png)
![3,5,9-Trioxa-4-phosphaheptacos-18-en-1-aminium,4-hydroxy-N,N,N-trimethyl-10-oxo-7-[[(9Z)-1-oxo-9-octadecen-1-yl]oxy]-, innersalt, 4-oxide, (7R,18Z)-](http://img.cochemist.com/ccimg/4300/4235-95-4.png)
![3,5,9-Trioxa-4-phosphaheptacos-18-en-1-aminium,4-hydroxy-N,N,N-trimethyl-10-oxo-7-[[(9Z)-1-oxo-9-octadecen-1-yl]oxy]-, innersalt, 4-oxide, (7R,18Z)-](http://img.cochemist.com/ccimg/4300/4235-95-4_b.png)
