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    Chinese Journal of Chromatography
    2008, Vol. 26, No. 4
    Online: 30 July 2008

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    兴奋剂检测方法专栏
    Advances and strategies in gene doping detection
    HE Jiangang, LIU Zhen, LIU Jing, DOU Peng, CHEN Hong-Yuan
    2008, 26 (4):  402-407. 
    Abstract ( 2706 )   [Full Text(HTML)] () PDF (354KB) ( 1254 )  
    This review surveys the recent status of gene doping detection and the strategies for anti-gene doping. The main gene doping candidates for athletes are summarized, and the advances in the detection of the proteins expressed by these genes such as erythropoietin (EPO) and human growth hormone (hGH) are reviewed. The potential detection strategies for further gene doping analysis are also discussed.
    Current status and prospects of gene doping detection
    WANG Wenjun, ZHANG Sichun, XU Jingjuan, XIA Xinghua, TIAN Yaping, ZHANG Xinrong, CHEN Hong-Yuan
    2008, 26 (4):  408-412. 
    Abstract ( 2655 )   [Full Text(HTML)] () PDF (136KB) ( 1104 )  
    The fast development of biotechnology promotes the development of doping. From recombinant protein to gene doping, there is a great challenge to their detection. The improvement of gene therapy and potential to enhance athletic performance open the door for gene doping. After a brief introduction of the concept of gene doping, the current status and prospects of gene doping detection are reviewed.
    Recent advances in the detection of recombinant human erythropoiesis and its analogs in doping control
    YANG Xia, PANG Nannan, LIAO Yiping, LIU Huwei
    2008, 26 (4):  413-416. 
    Abstract ( 2557 )   [Full Text(HTML)] () PDF (118KB) ( 1097 )  
    Recombinant human erythropoietin (rhEPO) is one of hormone dopings. In the recent years, it has been always misused in endurance competition sports. It is extremely difficult to discriminate between the natural endogenous erythropoietin (EPO) and recombinant exogenous hormone because they have identical amino acid sequences, and EPO has a relatively short half-life and very low concentration in blood or urine. In this paper, the research progress on the analysis and detection of rhEPO and its analogs by direct and indirect methods are reviewed. Future direction and prospects of the detection of rhEPO in doping control are discussed based on the research of our group.
    Research progresses of anabolic steroids analysis in doping control
    LONG Yuanyuan, WANG Dingzhong, LI Ke’an, LIU Feng
    2008, 26 (4):  417-423. 
    Abstract ( 2372 )   [Full Text(HTML)] () PDF (175KB) ( 1400 )  
    Anabolic steroids, a kind of physiological active substance, are widely abused to improve athletic performance in human sports. They have been forbidden in sports by the International Olympic Committee since 1983. Since then, many researchers have been focusing their attentions on the establishment of reliable detection methods. In this paper, we review the research progresses of different analytical methods for anabolic steroids since 2002, such as gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, immunoassay, electrochemistry analysis and mass spectrometry. The developing prospect of anabolic steroids analysis is also discussed.
    Recent progress in the development of analytical methods for insulin-like growth factor-I
    PAN Qiong, ZHAO Meiping, LI Yuanzong
    2008, 26 (4):  424-430. 
    Abstract ( 2322 )   [Full Text(HTML)] () PDF (321KB) ( 1090 )  
    Different methods for the pretreatment of insulin-like growth factor-I (IGF-I) and the derivatization of IGF-I are introduced. Detection methods such as immunoassay, chromatography, chromatography-mass spectrometry and surface plasma resonance (SPR) and so on are also reviewed.
    Applications and progresses of liquid chromatography-mass spectrometry in doping control
    QIN Yang, XU Youxuan, YANG Shumin, ZHU Shaotang
    2008, 26 (4):  431-436. 
    Abstract ( 2727 )   [Full Text(HTML)] () PDF (172KB) ( 1392 )  
    High performance liquid chromatography-mass spectrometry (LC-MS) has enabled the determination of most of the prohibited drugs in doping analysis, including many small molecular doping agents and peptide hormones. This paper reviews liquid chromatography-mass spectrometry for the screening, identification and quantification of doping agents in urine and other biological samples. Criteria for the identification of compounds by LC-MS are also discussed.
    Recent advances in the detection of human erythropoietin and human growth hormone doping
    GUO Lei, ZHANG Zhaoyang, TANG Jijun, XIE Jianwei
    2008, 26 (4):  437-443. 
    Abstract ( 2820 )   [Full Text(HTML)] () PDF (504KB) ( 1192 )  
    In the World Anti-doping Agency 2008 Prohibited List, the prohibited substances of S2 item are hormones and related substances, which are belonging to the endogenous biomacromolecules. How to identify the substances derived from endogenous secretion or exogenous administration is the main problem in doping control analysis and attracts more attention. The present report summarizes the main analytical strategies, including indirect blood tests and direct detection approaches developed to identify the presence of erythropoietin (EPO) and human growth hormone (hGH), which have wide pharmaceutical applications and thus been fully examined. The recent physico-chemical or immunoanalytical methodologies on the discrimination of recombinant and endogenous proteins are emphasized.
    A rapid capillary zone electrophoresis method for simultaneous determination of several kinds of doping agents
    XIAO Hui, TONG Ping, FENG Qiang, ZHANG Lan
    2008, 26 (4):  444-448. 
    Abstract ( 2762 )   [Full Text(HTML)] () PDF (512KB) ( 1122 )  
    A capillary zone electrophoresis-ultraviolet detection (CZE-UV) method was established for the simultaneous determination of eight doping agents which belong to diuretics, anabolic steroids, β-blocks, narcotics, β2-agonists and stimulants. Under the optimal conditions, with 50 mmol/L ammonium formate buffer (pH 7.8) as the running buffer, injection at a pressure of 3 kPa for 10 s, applied voltage of 20 kV, and detection at 214 nm, eight doping agents were separated quickly and completely within 7 min. The linearities of the eight doping anents were good in respective concentration ranges. Their detection limits were from 0.2 to 0.7 μg/mL. It is a simple and rapid method with small sample size for doping detection.
    Simultaneous analysis of ten anabolic steroids in blood plasma using high performance liquid chromatography
    ZHANG Lan, CHEN Jinfeng, TONG Ping, LI Tianlin
    2008, 26 (4):  449-453. 
    Abstract ( 2684 )   [Full Text(HTML)] () PDF (519KB) ( 1168 )  
    A method for the simultaneous separation and determination of ten anabolic steroids in blood plasma using high performance liquid chromatography (HPLC) was established. An RP-C18 column was used as the analytical column, and the mixture of acetonitrile and water was used as the mobile phase with gradient elution according to the characteristics of the analytes. The analytes were detected at the adjustable wavelengths ranging from 194 to 290 nm. Under the optimal conditions, ten compounds were separated within 10 min. The detection limits were in the range of 0.01-0.10 μg/mL. The spiked recoveries of standards in a rabbit plasma sample were from 70.3%to 120%. Methandriol was injected into the ear meridian of a rabbit, and then the anabolic steroid methandriol in the plasma was successfully detected with the established method. The results show that the method is feasible, rapid, simple and accurate.
    Determination of endogenous anabolic steroids in hair using gas chromatography-tandem mass spectrometry
    SHEN Min, XIANG Ping, SHEN Baohua, WANG Mengye
    2008, 26 (4):  454-459. 
    Abstract ( 2725 )   [Full Text(HTML)] () PDF (266KB) ( 1207 )  
    A method of gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed for the simultaneous identification and quantification of five endogenous anabolic steroids (testosterone, epitestosterone, androsterone, etiocholanolone, dehydroepiandrosterone) in hair. After alkaline hydrolysis, the hair sample was extracted with diethyl ether, derivatized with a derivatization reagent (N-methyl-N-trimethylsilyl-trifluoroacetamid/iodotrimethyisilane/DL-dithiothreitol, 1000∶5∶5, v/v/w) and detected using GC-MS/MS in the multiple-reaction monitoring mode. The one precursor/two product ion transitions for each anabolic steroids were monitored. The limits of detection for five endogenous anabolic steroids were in the range of 0.1-0.2 pg/mg. All analytes showed good linearity and the extraction recoveries were 74.6%-104.5%. The inter-day and intra-day relative standard deviations (RSD) were less than 17.5%. This method has been applied to the analysis of testosterone, epitestosterone, androsterone, etiocholanolone, dehydroepiandrosterone in 80 Chinese hair samples. These data are the suitable references and the basis for the interpretation of the results from endogenous steroids abuse.
    Screening, quantification and confirmation of β-blockers in urine using gas chromatography-mass spectrometry
    SHANGGUAN Liangmin, LIU Wei, ZHENG Xiangyang, ZHANG Lan
    2008, 26 (4):  460-464. 
    Abstract ( 2378 )   [Full Text(HTML)] () PDF (518KB) ( 1060 )  
    A method was developed to perform the screening, quantification and confirmation of the five β-blockers, propranolol, carteolol, bisoprolol, esmolol, and sotalol, in human urine using gas chromatography-mass spectrometry (GC-MS). In sample preparation, conjugated and unconjugated β-blockers in urine were extracted separately, and the extracts were combined. The extracts were derivatized with N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) and N-methyl-bis(trifluoroacetamide) (MBTFA). The optimal conditions of GC-MS were established, and the progresses of screening by selected ion monitoring (SIM) mode and confirmation by full scan (SCAN) mode were completed. At last, the quantification curves of the five β-blockers in spiked urine were established by SIM mode. The limits of detection were 0.2-1.0 ng/mL. Overall recoveries were 70.5%-103.4%, and the relative standard deviations were lower than 15%. In addition, the method was successfully applied to the analysis of the positive urine of propranolol, and the urinary excretion curve was also established accordingly. It is significant to prohibit the abuse of β-blockers in doping control.
    Determination of three anabolic steroids by liquid chromatography-mass spectrometry
    QIN Yang, LIU Xin, WANG Zhanliang, WU Moutian
    2008, 26 (4):  465-468. 
    Abstract ( 2553 )   [Full Text(HTML)] () PDF (544KB) ( 1105 )  
    A high performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI/MS) was developed to screen and determine trenbolone, tetrahydrogestrinone and gestrinone in human urine. The urine sample was enzymatically hydrolyzed with β-glucuronidase, then extracted with methyl tert-butyl ether. Chromatographic separation was performed on a Zorbax SB-C18 column (150 mm×2.1 mm, 5 μm) with ammonium formate buffer (pH 3.5) and acetonitrile as mobile phase. Using positive electrospray ionization mode, the effect of different parameters from electrospray chamber was investigated. The limits of detection based on signal noise ratio of 3 were between 1 and 5 ng. The method can be applied in screening and confirmation of the anabolic steroids in doping control.
    Determination of stanozolol in hair using liquid chromatography-tandem mass spectrometry
    XIANG Ping, SHEN Min, SHEN Baohua, YAN Hui
    2008, 26 (4):  469-472. 
    Abstract ( 2452 )   [Full Text(HTML)] () PDF (393KB) ( 1013 )  
    A rapid and sensitive method was developed for the identification and quantification of stanozolol in hair. After alkaline hydrolysis, the hair sample (10 mg) was extracted with pentane, and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI) and multiple reaction monitoring (MRM). The limit of quantification was found to be 25 pg/mg. After shaving hair on the back of the cavies, they were received after a single intraperitoneal dosing of stanozolol of 60 mg/kg. The hair segments were shaved once every two days for two weeks. The concentration of stanozolol in segmented hair reached the highest at the 10th day. The features of the method are of small sample size, specific, sensitive and suitable for the determination of stanozolol in hair.
    Articles
    Investigation on interaction between bovine serum albumin and liposome using capillary electrophoresis
    LI Hong, QU Feng, XU Jiandong, DENG Yulin
    2008, 26 (4):  473-477. 
    Abstract ( 2682 )   [Full Text(HTML)] () PDF (379KB) ( 692 )  
    A method for the investigation on the interaction between bovine serum albumin (BSA) and liposome using capillary electrophoresis was developed. The oxidation index showed that the liposomes after freeze-drying were more stable. The results obtained from the capillary electrophoretic analysis of liposome showed that liposome had no charge at pH 5.0-8.0. A series of liposome suspension at different concentrations with the internal marker of 0.8% dimethyl sulfoxide (DMSO) were introduced as the electrophoresis buffer at pH 7.0. Along with the liposome concentrations raised from 0 to 2.4 mg/mL, it was found that the effective mobility of BSA changed from -2.232×10-4 cm2·V-1·s-1 to -3.046×10-4 cm2·V-1·s-1. The binding constant between BSA and liposome was 2.522×103(g/mL)-1 calculated by Scatchard analysis. This method is simple and rapid, and provides a new technology for the investigation on the interactions between protein and liposome.
    Distribution determination of nitrogen compounds in catalytic diesel oil using gas chromatography
    YANG Yongtan
    2008, 26 (4):  478-483. 
    Abstract ( 2523 )   [Full Text(HTML)] () PDF (622KB) ( 916 )  
    The method for the separation and determination of nitrogen compounds in catalytic diesel oil using gas chromatography-nitrogen chemiluminescence detection (GC-NCD) was established. The effects of the flow rate of carrier gas and oven temperature on the resolution were studied. More than 80 nitrogen compounds (such as aniline, alkyl anilines, quinoline, indole, alkyl indoles, carbazole, alkyl carbazoles) in catalytic diesel oil were enriched using an Al2O3 column and identified based on the retention time of some pure nitrogen compounds and the retention index of nitrogen compounds on GC-NCD. The relative standard deviations of the peak areas of main nitrogen compounds in catalytic diesel oil were lower than 8%. The detection limit (S/N=3) for nitrogen of carbzole was 1.0 mg/L under the chosen conditions. The linear range of nitrogen was 1.0-600 mg/L for each nitrogen compound. The correlation coefficient was more than 0.998. The recoveries of four nitrogen compounds (aniline, quinoline, indole, carbazole) in catalytic diesel oil were in the range of 89.5%-99.8%. The method can be applied for the determination of each nitrogen compound in different catalytic diesel oils.
    Analysis of organochlorine pesticides in buckwheat using pressurized liquid extraction and gas chromatography
    LIAN Mei, XU Feng, GUAN Wenna, XU Yuan, GUAN Yafeng
    2008, 26 (4):  484-488. 
    Abstract ( 2836 )   [Full Text(HTML)] () PDF (862KB) ( 755 )  
    Seven organochlorine pesticides (OCPs) in buckwheat were extracted by a homemade 24 cells auto-pressurized liquid extraction instrument (APLE) and then analyzed by gas chromatography with electronic capture detection. The optimal extraction condition was found to be 100 ℃ and 10 MPa for 5 min with acetone/n-hexane (1∶1, v/v) as the extraction solvent. The extraction was performed twice for each sample to obtain complete extraction. The buckwheat was mixed with florisil and active carbon before filling into extraction cells. Concentrated sulfuric acid was used in clean up step of the extractant. The standard mixture of OCPs including α-benzene hexachloride (BHC), γ-BHC, δ-BHC, p,p′-dichloro-diphenyl-dichloroethylene (p,p′-DDE), p,p′-dichloro-diphenyl-dichloroethane (p,p′-DDD), o,p-dichloro-diphenyl trichloro-ethane (o,p-DDT), p,p′-DDT was used for the identification and quantification in gas chromatographic analysis. The absolute recoveries of the 7 organochlorine pesticides were between 68%-126% with the relative standard deviations lower 14.7%. The detection limits were between 0.051-0.18 ng/g. The relative recoveries were as high as 116%-148% compared with Soxhlet extraction. It shows that the recoveries of APLE are much better than Soxhlet extraction, and the time of extraction for APLE is only about 15 min which is much less than conventional extraction methods.
    Linear scale-up of the separation of active components from Oroxylum indicum using high-speed counter-current chromatography
    YUAN Yuan, LUO Houding, CHEN Lijuan
    2008, 26 (4):  489-493. 
    Abstract ( 2827 )   [Full Text(HTML)] () PDF (309KB) ( 778 )  
    High-speed counter-current chromatography was used to separate and purify flavonoids from the ethyl acetate extract of Oroxylum indicum. After the optimization of separation conditions on analytical instrument, including the two-phase solvent system, rotation speed, flow rate, sample volume and sample concentration, a linear scale-up procedure was performed at preparative grade. Chrysin (160.9 mg, 97.3% in purity), baicalein (130.4 mg, 97.6% in purity), baicalein-7-O-glucoside (314.0 mg, 98.3% in purity), baicalein-7-O-diglucoside (179.1 mg, 99.2% in purity), and a new chrysin-diglucoside (21.7 mg, 98.8% in purity) were obtained from 911.6 mg ethyl acetate extract of Oroxylum indicum by only one step. These five compounds were identified using high performance liquid chromatography, mass spectrometry and nuclear magnetic resonance. With the improvement of the throughput for 53 times after such a scale-up, the resolution and the separation time were kept as the same as those of the analytical grade separation. Therefore, the linear scale-up provided an efficient method for the separation of natural products.
    Determination of 11 fatty acids and fatty acid methyl esters in biodiesel using ultra performance liquid chromatography
    LI Yizhe, BAO Guirong, WANG Hua
    2008, 26 (4):  494-498. 
    Abstract ( 2813 )   [Full Text(HTML)] () PDF (229KB) ( 1327 )  
    A method for the determination of 11 familiar components in biodiesel was developed using ultra performance liquid chromatography with evaporative light scattering detector (UPLC-ELSD). These components were oleic acid, methyl cis-9-octadecenoate, linoleic acid, methyl linoleate, stearic acid, methyl octadecanoate, methyl linolenate, palmitic acid, methyl hexadecanoate, erucic acid and myristic acid. The sample was dissolved in methanol after extraction from the products. The separation column was an Acquity UPLC BEH Phenyl Cl8 (100 mm×2.1 mm, 1.7 μm) and the mobile phase was acetonitrile-water (3∶1, v/v). An isocratic elution program was utilized for the separation. The flow rate was 0.3 mL/min and the column temperature was 40 ℃. The parameters of ELSD were as follows: the plus was 80; the temperature of the drift tube was 45 ℃; the eluant gas pressure was 172 kPa. The sample was detected by ELSD in only 5 min. The calibration curves of 11 components showed good linearity with the correlation coefficients greater than 0.997. In comparison with other methods, this method is simple, fast, and has a good separation efficiency. The fatty acids and fatty acid methyl esters were separated in one step, thus, the extent of reaction can be confirmed by the determination of their contents. This method can be routinely used for the determination of the fatty acids and fatty acid methyl esters in the reaction products and the final biodiesel.
    Determination of quinoxyfen residue in foodstuffs of plant and animal origins by high performance liquid chromatography
    YANG Fang, LU Shengyu, CHEN Xiangming, LI Jie, LIU Zhengcai, LIN Yonghui, LAN Jinchang, CHEN Guonan
    2008, 26 (4):  499-503. 
    Abstract ( 2732 )   [Full Text(HTML)] () PDF (338KB) ( 601 )  
    A high performance liquid chromatographic (HPLC) method has been developed for the determination of quinoxyfen residue in various food matrixes including soybean, cauliflower, cherry, mushroom, wine, tea, honey, pork liver, chicken and eel. The analyte was extracted by ethyl acetate, and then purified with aminopropyl solid phase extraction (NH2 SPE) cartridge. Post-extraction gel permeation chromatography (GPC) was used for animal (except honey) and fishery products prior to NH2 SPE cleanup.The average recoveries and relative standard deviations (RSDs) for the analysis of all samples fortified in the range of 0.010-5.0 mg/kg were in the ranges of 82%-96% and 3.2%-11.8%, respectively. Good linearity was obtained in the concentration range from 0.050 to 50.0 mg/L. The limit of detection was 0.010 mg/kg. The proposed method was successfully applied to the analysis of quinoxyfen residue in various food samples.
    Simultaneous determination of six cucurbitane triterpene glycosides in Siraitia grosvenorii fruits using high performance liquid chromatography
    LU Fenglai, LIU Jinlei, HUANG Yonglin, LI Dianpeng
    2008, 26 (4):  504-508. 
    Abstract ( 2584 )   [Full Text(HTML)] () PDF (372KB) ( 705 )  
    Siraitia grosvenorii, a traditional Chinese fruit, belongs to the family Cucurbitaceae and has been used as a pulmonary demulcent and emollient for the treatment of dry cough, sore throat, dire thirst, and constipation in folk medicine. A high performance liquid chromatographic method was developed for simultaneous determining the contents of mogrosideⅤ, mogrosideⅣA, mogrosideⅢ, 11-oxomogrosideⅢ, mogrosideⅡE and 11-oxomogrosideⅡE in Siraitia grosvenorii fruits. The chromatographic analysis was carried out on a ZORBAX SB-C18 column (150 mm×4.6 mm, 5 μm). The mobile phase was water (A) and acetonitrile (B) with gradient elution (0-3 min, 20%B-30%B; 3-8 min, 30%B-35%B; 8-9 min, 35%B). The flow rate was maintained at 0.8 mL/min. The detection wavelength was set at 203 nm and the column temperature was controlled at 30 ℃. The sample injection volume was 10 μL. The calibration curves were linear over the ranges of 0.04-1.0 mg/mL, 0.011-0.68 mg/mL, 0.010-0.80 mg/mL, 0.0097-0.58 mg/mL, 0.025-1.0 mg/mL and 0.013-0.76 mg/mL (r>0.9991) for the above cucurbitane triterpene glycosides, respectively. The average recoveries were 99.65% for mogrosideⅤ, 101.6% for mogroside ⅣA, 97.05% for mogroside Ⅲ, 103.1% for 11-oxomogrosideⅢ, 99.25% for mogrosideⅡE, and 103.0% for 11-oxomogrosideⅡE, with the relative standard deviations of 0.83%, 3.1%, 1.9%, 3.3%, 0.59% and 2.0%, respectively. This simple, rapid and accurate method is suitable for quality control and determination of raw materials and products of Siraitia grosvenorii fruits.
    Characterization of aroma active compounds in blood orange juice by solid phase microextraction and gas chromatography-mass spectrometry-olfactometry
    QIAO Yu, XIE Bijun, ZHANG Yan, ZHANG Yun, PAN Siyi
    2008, 26 (4):  509-514. 
    Abstract ( 2955 )   [Full Text(HTML)] () PDF (279KB) ( 710 )  
    Volatile compounds of fresh blood orange juice were analyzed by solid phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS) and the aroma active compounds were identified by olfactometry. The volatile compounds were extracted by headspace solid phase microextraction (HS-SPME) using a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber for 40 min at 40 ℃. The analysis was carried out using an HP 6890N GC equipped with an HP-5 column (30 m×0.25 mm×0.25 μm ) directly connected to an HP 5975 series mass selective detector and a sniffing port (ODP2, Gerstel) using helium as carrier gas. Compound identifications were made by the comparison of the mass spectra, retention times, retention indices (IR) and odor of the volatile components in the extracts with those of the corresponding reference standards. Forty-six compounds were identified by GC-MS and IR. The major components of the juice were limonene (86.36%), linalool (3.69%), β-myrcene (1.79%), octanal (1.32%) and valencene (1.27%). GC-MS-olfactometry analysis was performed to determine 34 compounds with aroma activity, of which 23 compounds were identified. The major contributors to orange juice aroma activity are ethyl butanoate, octanal, γ-terpinene, 4-acetyl-1-methylcyclohexene, decanal, (-)-carvone, geranyl acetate, valencene. These compounds of strong aroma intensity represent 7.22% of the total volatile compounds. Other four unknown compounds (IR<800; IR=1020, 1143, 1169, separately) are also the major contributors to the overall aroma.
    Determination of triadimenol residue in foods with dispersive solid phase extraction cleanup by gas chromatography-negative chemical ionization mass spectrometry
    SHEN Weijian, LIN Hong, ZHAO Zengyun, DING Tao, XU Jinzhong, SHEN Chongyu
    2008, 26 (4):  515-518. 
    Abstract ( 3316 )   [Full Text(HTML)] () PDF (236KB) ( 867 )  
    A confirmatory method is presented for the determination of triadimenol residue in foods by dispersive solid phase extraction-gas chromatography-negative chemical ionization mass spectrometry (SPE-GC-NCI/MS). Triadimenol residue was extracted from different food samples, such as snow pea, carrot, orange, bean, spinach, oolong tea, rice, beef, longsnout catfish, royel jelly, red swamp crayfish, bee honey etc with acetonitrile containing 1% acetic acid and simultaneous liquid-liquid partitioning formed by adding anhydrous magnesium sulfate plus sodium acetate, followed by a simple clean-up step known by dispersive solid-phase extraction. The aliquot was determined and confirmed by gas chromatography-negative chemical ionization mass spectrometry using external standard method. The average recoveries at the three spiked levels (0.005, 0.010 and 0.020 mg/kg) in different samples ranged from 70% to 110%, and the relative standard deviations were lower than 12.0%. The linearity of detection ranged from 0.050 to 0.750 mg/L. The detection limit of the method was 0.001 mg/kg and the limit of quantification was 0.003 mg/kg. The method is selective with no interference and suitable for confirmatory of triadimenol residue in 12 categories of foods.
    Characterization of pyrolysis of waste printed circuit boards by high-resolution pyrolysis gas chromatography-mass spectrometry
    ZHANG Yanhong, HUANG Hong, XIA Zhengbin, CHEN Huanqin
    2008, 26 (4):  519-522. 
    Abstract ( 2442 )   [Full Text(HTML)] () PDF (423KB) ( 615 )  
    Thermal degradation of pyrolysis of waste circuit boards was investigated by high-resolution pyrolysis gas chromatography-mass spectrometry (PyGC-MS) and thermogravimetry (TG). In helium atmosphere, the products of FR-4 waste printed circuit board were pyrolyzed at 350, 450, 550, 650, and 750 ℃, separately, and the pyrolysis products were identified by on-line MS. The results indicated that the pyrolysis products of the FR-4 waste circuit board were three kinds of substances, such as the low boiling point products, phenol, bisphenol and their related products. Moreover, under 300 ℃, only observed less pyrolysis products. As the increase of pyrolysis temperature, the relative content of the low boiling point products increased. In the range of 450-650 ℃, the qualitative analysis and character were similar, and the relative contents of phenol and bisphenol were higher. The influence of pyrolysis temperature on pyrolyzate yields was studied. On the basis of the pyrolyzate profile and the dependence of pyrolyzate yields on pyrolysis temperature, the thermal degradation mechanism of brominated epoxy resin was proposed.
    Technical Notes
    Optimization of the collection region in preparative high performance liquid chromatography with exponentially modified Gaussian (EMG) model
    WANG Longxing, GAO Mingzhe, XIAO Hongbin
    2008, 26 (4):  523-525. 
    Abstract ( 2520 )   [Full Text(HTML)] () PDF (3448KB) ( 696 )  
    Preparative high performance liquid chromatography (HPLC) are widely used recently. The optimization of its operating conditions is important for improving efficiency and saving operating cost. Now, most works such as linear scale up technology were focused on the optimization of mobile phase. The sample collection region is another important operating parameter in preparative HPLC. In this study, a software was written according to the exponentially modified Gaussian (EMG) model. With this software, the operators of preparative HPLC can easily choose a suitable sample collection region.
    Determination of cyflufenamid residue in carrots by gas chromatography-negative chemical ionization mass spectrometry
    YANG Wenquan, SHEN Weijian, ZHAO Zengyun, XU Jinzhong, SHEN Chongyu, WU Bin
    2008, 26 (4):  526-528. 
    Abstract ( 2736 )   [Full Text(HTML)] () PDF (302KB) ( 637 )  
    A method was developed for the determination of cyflufenamid residue in carrots by solid phase extraction-gas chromatography-negative chemical ionization mass spectrometry (SPE-GC-NCI/MS). Cyflufenamid residue was extracted with ethyl acetate from carrots. The extract was cleaned-up by an active carbon SPE column connected to a neutral alumina SPE column. The analysis was carried out by the GC-NCI/MS with selected ion monitoring mode. The recoveries of cyflufenamid in carrot samples were in the range from 74.9% to 94.6% at four spiked levels, 0.005, 0.01, 0.02, 0.04 mg/kg, and the relative standard deviations (RSD) were less than 9.7% for inter-days. The linearity of the method was good in the range from 10 to 1000 ng/mL, and the limit of detection (LOD) was 0.001 mg/kg, and the limit of quantitation (LOQ) was 0.005 mg/kg. The method is selective without interference and is suitable for the determination and confirmation of cyflufenamid residue in carrots.