Loading...

List of Issues

    Chinese Journal of Chromatography
    2009, Vol. 27, No. 6
    Online: 30 November 2009

    For Selected: Toggle Thumbnails
    Reviews
    Research progress in supramolecular compounds-based stationary phases for capillary electrochromatography
    TIAN Yun, CAO Xiaomin, ZHANG Qi, ZENG Zhaorui
    2009, 27 (6):  737-744. 
    Abstract ( 2012 )   [Full Text(HTML)] () PDF (265KB) ( 962 )  
    Supramolecular chemistry is a new branch of sciences, which deals with the specific recognitions between molecules. The host-guest interactions, which exert by supramolecular compounds, can provide a promising prospect for chromatographic separations with high selectivities. Capillary electrochromatography (CEC) is defined as a very promising micro-separation technique with high efficiency and high selectivity in recent years. As the key component of CEC, the stationary phases have been the research focus of CEC development. This paper reviews the recent progress in supramolecular compounds-based stationary phases (cyclodextrin, calixarene, crown ether and macrocyclic polyamine) for CEC since 1998.
    Communications
    Quantitative determination of steroids in the fruiting bodies and submerged-cultured mycelia of Inonotus obliquus
    GAO Yuan, XU Hongyu, LU Zhenming, XU Zhenghong,
    2009, 27 (6):  745-749. 
    Abstract ( 2067 )   [Full Text(HTML)] () PDF (211KB) ( 847 )  
    This study describes the method of quantitative determination of betulin, ergosterol, cholesterol, lanosterol, stigmasterol and sitosterol in the fruiting bodies and submerged-cultured mycelia of Inonotus obliquus. A high performance liquid chromatographic (HPLC) method was applied to separate these steroids. The procedure was carried out on a reversed-phase C18 column, using a stepwise gradient of water-methanol as mobile phase with the following profile: 0~10 min, 10% water, 90% methanol; 10~40 min, 3% water, 97% methanol. The flow rate was 1.4 mL/min and the detection wavelength was 202 nm. The analysis was completed within 40 min. The results showed that this method has good reproducibility and satisfactory recoveries for the determination of steroids. The relative standard deviations of the peak areas were less than 2.94% (n=5) for intraday assays. A good linear correlation was obtained in a range of 0.4~4.8 μg. The recoveries of betulin, ergosterol, cholesterol, lanosterol, stigmasterol, and sitosterol were 100.05%~100.72%, 99.31%~101.04%, 97.52%~101.63%, 96.61%~100.08%, 96.21%~100.76% and 100.04%~100.51%, respectively. This method can be applied to evaluate real samples, and it is rapid, accurate and suitable for the quantitative determination of steroids in the fruiting bodies and submerged-cultured mycelia of Inonotus obliquus.
    Articles
    Evaluation of chromatographic performance of polymerized ionic liquid stationary phase for capillary gas chromatography
    CHEN Xiaoyan, LU Kai, QI Meiling, FU Ruonong
    2009, 27 (6):  750-754. 
    Abstract ( 2243 )   [Full Text(HTML)] () PDF (179KB) ( 803 )  
    The selectivity and thermal stability of ionic liquids as the stationary phases for capillary gas chromatography (CGC) have attracted much attention of researchers in recent years. In this study, 1-vinyl-3-benzyl imidazolium-bis(trifluoromethane-sulphonyl)imidate (VBIm-NTf2) was synthesized and polymerized (PVBIm-NTf2) in a CGC column. In comparison with VBIm-NTf2, PVBIm-NTf2 exhibits much better thermal stability and chromatographic selectivity, and achieves satisfactory resolution for Grob test mixture, alcohols mixture, esters mixture and aromatics mixture with narrow and symmetric peak shapes. The satisfactory resolution and selectivity of the polymerized column still remain after conditioned at 250 ℃ for 6 h. Additionally, the Abraham solvation parameters of PVBIm-NTf2 were determined and the interactions between the stationary phase and solutes were elucidated. The present work demonstrates that the polymerization is an effective way to improve the selectivity and thermal stability of common ionic liquids as CGC stationary phases.
    Analysis of solvent residues in raw material drug of glimepiride by head-space sampling-capillary gas chromatography
    ZHU Bo, ZHAO Luqing, CHEN Anzhen, HUA Yuqin, LUAN Chengzhang
    2009, 27 (6):  755-759. 
    Abstract ( 2609 )   [Full Text(HTML)] () PDF (166KB) ( 1234 )  
    An analytical method for the solvent residues in the raw material drug of glimepiride has been established by head-space sampling capillary gas chromatography. General evaluation was made for the distribution of organic residual solvents in glimepiride samples from 8 different domestic manufacturers. Based on the evaluation-test results and the information provided by manufacturers, 14 target solvents were ascertained including acetone, ethyl acetate, methanol, isopropanol, ethanol, chloroform, toluene, 1,4-dioxane, pyridine, chlorobenzene, ether, dichloromethane, n-hexane and benzene. The target solvents were divided into two groups for baseline separation according to their column-retention specificity. Acetone, ethyl acetate, methanol, isopropanol, ethanol, chloroform, toluene, 1,4-dioxane, pyridine and chlorobenzene were separated on a Supelco-Wax capillary column with acetonitrile as internal standard, while ether, dichloromethane, n-hexane and benzene were determined on a Supelco OVI-G43 capillary column with butanone as internal standard. Linear responses were obtained for the 14 residual solvents in their respective concentration ranges (r=0.99167~0.99997, n=8), and the limits of detection were 0.2~13.5 μg/g. The inter-day reproducibilities, measured as relative standard deviations (RSDs), were 0.6%~9.2% (n=3). The average recoveries of three concentration levels were 86.3%~104.1% with the RSD of 0.2%~5.3% (n=16). The developed method is simple, sensitive, and accurate for the residual solvent analysis in glimepiride samples.
    Determination of fenbutatin oxide residue in orange products by gas chromatography
    LIU Zhixing, GUO Ping, WANG Yuanxing, ZHAN Chunrui, ZUO Haigen
    2009, 27 (6):  760-763. 
    Abstract ( 2460 )   [Full Text(HTML)] () PDF (130KB) ( 693 )  
    An analytical method for the determination of fenbutatin oxide (FBT) residue in oranges by capillary gas chromatography-flame photometric detection (GC-FPD) was developed. The FBT was extracted with acetone-acetic acid (99:1, v/v) and hexane, filtered and evaporated by nitrogen evaporator in a water bath at 35 ℃. The residue was dissolved in hexane. The FBT in the solvent was derivatized with ethyl magnesium bromide for 15 min, 1 mol/L hydrochloride was added, the supernatant was collected and the solvent was evaporated to get dry supernatants, then the supernatant was dissolved in hexane and cleaned up with a silica solid phase extraction column, eluted with 5 mL hexane-dichloromethane (4:1, v/v), determined by GC. The standard curve was linear in the range of 0.2~2.0 mg/L. The correlation coefficients (r) were more than 0.9995, the average recoveries were 79.6%~109.6% with the relative standard deviations (RSDs) of 3.60%~9.04% at the spiked levels of 0.1~0.4 mg/kg, and the detection limit of fenbutatin oxide was 0.1 mg/kg. This method is suitable for the analysis of fenbutatin oxide residue in orange products.
    Preparation and evaluation of Sudan Red I molecularly imprinted polymer
    DAI Qing, WANG Yan, BAO Xuewei, JING Tao, HAO Qiaoling, ZHOU Yikai, MEI Surong
    2009, 27 (6):  764-768. 
    Abstract ( 2275 )   [Full Text(HTML)] () PDF (197KB) ( 1318 )  
    The molecularly imprinted polymer (MIP) was prepared by precipitation polymerization using Sudan Red I as the template. To investigate the influence of porogenic solvent and the amount of template on recognition property, selective chromatographic evaluation and frontal chromatography were performed. The results indicated that the obtained MIP had the best affinity and selectivity to the template when the molar ratio of template to functional monomer was 1:8 and a mixture of 30 mL methanol and 10 mL acetonitrile was used as the porogenic solvent. The imprinted factor of optimal MIP for Sudan Red I was 2.32, and the total amount of the immobilized ligand was 0.50 μmol/g. This MIP displayed good specific recognition property for Sudan Red I and was used as the sorbent of solid phase extraction (SPE) to determine trace Sudan Red I in chili powders. The linear range was from 10 to 500 μmol/L with a correlation coefficient of 0.999. The detection limit was 3.3 μmol/L, the spiked recovery was between 95.87% and 98.41%, and the relative standard deviation (RSD) was lower than 3.1%. The developed method can be used for the routine detection of Sudan Red I in chili powders.
    Application of three-phase hollow fiber liquid-phase microextraction for analysis of hydroxybenzoic acids
    ZHU Ying, CHEN Xuan, ZHENG Feilang, BAI Xiaohong
    2009, 27 (6):  769-775. 
    Abstract ( 2257 )   [Full Text(HTML)] () PDF (263KB) ( 657 )  
    Under the optimal experimental conditions of three-phase hollow fiber liquid-phase microextraction (3p-HFLPME), the behaviors of hydroxybenzoic acids (HBAs) were investigated. The correlativities between the enrichment factor (EF) of HBAs and their n-heptanol/water conditional distribution coefficients (log Pn-heptanol/5 mmol/L HCl), pKa and the number of ~OH (N); the extraction mechanism that polyvinylidene difluoride hollow fiber contributed to promote the extraction efficiency by forming charge transfer compound with HBAs and the organic solvents showed notable selectivity for HBAs were elucidated. The optimal 3p-HFLPME conditions were: MOF 503 polyvinylidene difluoride hollow fiber as organic solvent supporter, n-heptanol as organic phase, 5 mmol/L HCl in the donor phase and 80 mmol/L NH3·H2O as the acceptor phase, the HBAs were extracted for 35 min under an agitation of 1200 r/min. It was found that the relative standard deviations were lower than 3%, the detection limits were 0.09~30.00 μg/L, the average recoveries of HBAs in Calyx Kaki were 93.3%~107.1% and the EF of HBAs at 5 mg/L was up to 107.6 fold.
    Discrimination of Ganoderma based on high performance liquid chromatographic fingerprints combined with chemometrics methods
    ZHANG Jingli, LUO Xia, ZHENG Linyong, XU Xiaoyan, YE Liming
    2009, 27 (6):  776-780. 
    Abstract ( 2331 )   [Full Text(HTML)] () PDF (241KB) ( 721 )  
    High performance liquid chromatography (HPLC)-based system was utilized for generating chemical fingerprints of 11 Ganoderma strains. The data were statistically evaluated by using chemometric methods in order to classify the samples. The similarities of all the 11 samples and the relative peak areas of 13 common peaks were newly calculated separately. Then different chemometrics methods including hierarchical cluster analysis (HCA), principal component analysis (PCA) and discriminate analysis (DA) were applied to classify the G. lucidum samples. Consistent results show that the application of HPLC fingerprint coupled with powerful chemometrics analysis in the discrimination and classification of Ganoderma is a reliable and scientific approach.
    High performance liquid chromatographic fingerprints of Baihe Zhimu Tang and its correlation to single herb
    QIN Kunming, FANG Qianbo, CAI Hao, LI Weidong, CAI Baochang
    2009, 27 (6):  781-786. 
    Abstract ( 2254 )   [Full Text(HTML)] () PDF (283KB) ( 721 )  
    The high performance liquid chromatographic (HPLC) fingerprints of Baihe Zhimu Tang were established for evaluating the effective substance basis and compatibility regulation of Baihe Zhimu Tang. An Agela Venusil XBP-C18 column(250 mm × 4.6 mm, 5 μm)was employed, and the gradient elution of acetonitrile and 0.1% formic acid was used as mobile phase with a flow rate of 1 mL/min, the detection wavelength was set at 315 nm, and the column temperature was set at 25 ℃. By taking mangiferin as the reference substance, the fingerprints of 10 batches of Baihe Zhimu Tang prepared by Bulbus Lilii and Rhizoma Anemarrhenae from different producing areas were analyzed under the same chromatographic conditions. The results showed that there were 16 common peaks contained in the tested samples. Five constituents were identified as 5-hydroxymethyl-2-furaldehyde (5-HMF), neomangiferin, mangiferin, isomangiferin and regaloside B by comparing the retention times and ultraviolet spectra of the peaks with those of the reference substances. The HPLC fingerprints of Baihe Zhimu Tang established with the above method show good characteristic and repeatability, and the method is stable and reliable, it can be used for the quality control of Baihe Zhimu Tang. The main chromatographic peaks of the HPLC fingerprints of Baihe Zhimu Tang were identified in the experiment and also 5-HMF was identified as the main constituent which changed significantly in decocting process.
    Determination of 61 central nervous system drugs in plasma by protein precipitation-high performance liquid chromatography
    ZHANG Yin, CHEN Chonghong, LIN Ling, CHEN Yinong
    2009, 27 (6):  787-793. 
    Abstract ( 2148 )   [Full Text(HTML)] () PDF (231KB) ( 749 )  
    A method was established for the determination of 61 central nervous system drugs in plasma by using protein precipitation combined with high performance liquid chromatography-diode array detection (HPLC-DAD). A volume of 1.5 mL acetonitrile was added into 1 mL plasma, after vortex, centrifugation and filtration, the supernatant was directly injected into HPLC. The separation was performed on an Agilent TC-C18 column (250 mm×4.6 mm, 5 μm) with acetonitrile and phosphate buffer solution as mobile phase by gradient elution at a flow rate of 1.5 mL/min. The detection wavelength was 210 nm; full spectra were recorded from 200~364 nm. The recoveries of 61 drugs were larger than 80% with the relative standard deviations (RSDs) ranged from 0.94% to 11.23%. The protein precipitation method is simple, rapid, low-cost with good recoveries, reproducibility and suitable for the general pretreatment of the systematic toxicological analysis (STA) of the 61 drugs.
    Determination of netilmicin in rat plasma by reversed-phase high performance liquid chromatography with fluorescence detection and pre-column derivatization
    CHANG Xiaojuan, PENG Jingdong, LIU Shaopu, LIU Limin, DAI Yongkuang
    2009, 27 (6):  794-798. 
    Abstract ( 2318 )   [Full Text(HTML)] () PDF (195KB) ( 733 )  
    A new, simple and sensitive method based on pre-column derivatization by reversed-phase high performance liquid chromatography (HPLC) is described for the separation and quantification of netilmicin in plasma, using 9-fluorenylmethyl chloroformate (FMOC-Cl) as the derivatization reagent. Its pharacokinetics is also presented. The derivatization modes and chromatographic conditions were optimized. The separation was performed on an Agilent ZORBAX Eclipse XDB-C8 column (150 mm×4.6 mm, 5 μm) with a mixture of water-acetonitile (15:85, v/v) as mobile phase and the flow rate was 1.0 mL/min. The excitation wavelength was 265 nm and the emission wavelength was 315 nm. The linear range was 0.045~8.88 mg/L and the correlation coefficient (r) was 0.9993. The limit of detection (LOD) (S/N=3) was about 0.01 mg/L, and the limit of quantification was 0.03 mg/L (3LOD) for netilmicin. The relative standard deviation was less than 3% for intra-day assay (n=5) and 3.5% for inter-day assay (n=5) and the relative recovery was in the range of 96.62%~100.84%(n=3). The plasma volume of 30 μL was sufficient for the determination of netilmicin. The method provides a reliable bioanalytical methodology to carry out netilmicin pharmacokinetics in rat plasma.
    Dispersive liquid-liquid microextraction coupled with high performance liquid chromatography for the determination of polynuclear aromatic hydrocarbons in environmental water samples
    ZHANG Jianhua, HUANG Ying, CHEN Xiaoqiu, CHEN Jinhua, LI Hui, CHEN Guonan
    2009, 27 (6):  799-803. 
    Abstract ( 2474 )   [Full Text(HTML)] () PDF (229KB) ( 857 )  
    A simple, rapid and effective method, the dispersive liquid-liquid microextraction coupled with high performance liquid chromatography-fluorescence detection (DLLME-HPLC-FLD), has been developed for the extraction and determination of polynuclear aromatic hydrocarbons (PAHs) in environmental water samples. The factors relevant to the microextraction efficiency, such as type and volume of dispersion agent and extraction solvents and the extraction time were investigated and optimized. Under the optimized extraction conditions, the reliability of the proposed method was evaluated. The linear response of this method was in the range of 0.01~10 μg/L (r ≥ 0.9913), the relative standard deviations (RSDs) of peak area for 0.05 μg/L PAHs were in the range of 2.3%~4.7% (n=6). At room temperature, the method exhibited excellent enrichment factors and good recoveries, 674~1032 and 67.4%~103.2% respectively. The detection limits (S/N=3) were in the range of 0.0003~0.002 μg/L. The developed method was applied to the determination of 15 PAHs in the water from Aojiang river, the average recoveries were 79.5%~92.3% with RSD of 4.3%~6.7%(n=5). The developed method is suitable for the analysis of trace PAHs in environmental water samples.
    Determination of six p-hydroxybenzoates in fruits and jams using solid-phase extraction-high performance liquid chromatography
    CHEN Ai, HE Qiaosang, WANG Pingya, ZHOU Yong, HUANG Li, XU Zhenjian, ZHAO Hua, ZHANG Weiying
    2009, 27 (6):  804-808. 
    Abstract ( 2421 )   [Full Text(HTML)] () PDF (172KB) ( 1336 )  
    A method was developed for the determination of 6 p-hydroxybenzoates (methyl p-hydroxybenzoate (MHB), ethyl p-hydroxybenzoate (EHB), isopropyl p-hydroxybenzoate (IPHB), propyl p-hydroxybenzoate (PHB), isobutyl p-hydroxybenzoate (IBHB) and butyl p-hydroxybenzoate (BHB)) in fruits and jams using the combination of solid-phase extraction and high performance liquid chromatography (SPE-HPLC). Two different extraction solutions and three different mobile phases were tested for p-hydroxybenzoates analysis, and finally ethanol was used as the extraction solvent and methanol-citric acid buffer was selected as the mobile phase. The sample was extracted, and purified by an Oasis HLB solid-phase extraction cartridge, then separated on a Symmetry-C18 column and detected at the wave length of 258 nm. The results showed that all the calibration graphs were linear in the concentration range of 0.1~20.0 mg/L (r=0.9999). The detection limits and quantification limits were 0.1 mg/kg (S/N=3) and 0.3 mg/kg (S/N=10) respectively for MHB, EHB, IPHB and PHB, 0.2 mg/kg (S/N=3) and 0.6 mg/kg (S/N=10) respectively for IBHB and BHB. The average recoveries were between 82.8% and 115.5% with the relative standard deviations (RSDs) of 0.2%~6.8%(n=6). The method is simple, rapid, sensitive and reproducible, and can be used for the routine analysis of the p-hydroxybenzoates in fruits and jams.
    Extraction chromatographic separation of platinum(IV) from real samples and associated elements
    KOKATE Sudarshan Jagdish, KUCHEKAR Shashikant Raghunath
    2009, 27 (6):  809-814. 
    Abstract ( 1976 )   [Full Text(HTML)] () PDF (268KB) ( 490 )  
    The extraction behavior of platinum(IV) was studied with N-n-octylaniline as a function of different parameters, such as pH, concentrations of weak acids, mineral acids, reagents and elution time. A selective method was developed for the extraction chromatographic studies of platinum(IV) and its separation from several metal ions with N-n-octylaniline (liquid anion exchanger) as a stationary phase on silica gel. The quantitative extraction of platinum(IV) was observed with 0.067 mol/L N-n-octylaniline and 0.015 mol/L ascorbic acid at pH 1.0. Metal ion was stripped from the column with water and determined spectrophotometrically with stannous chloride method. The proposed method is free from the interference of a large number of cations and anions. Platinum(IV) was separated from pharmaceutical preparations, alloys and synthetic mixtures. Mutual separation scheme was developed for platinum(IV), palladium(II) and gold(III). The log-log plot of N-n-octylaniline concentration versus the distribution ratio indicates that the probable extracted species is [RR′NH+2 ]· Pt(C6H7O6)-3.
    Determination of 5 polyether antibiotics in chicken tissues by liquid chromatography-electrospray ionization tandem mass spectrometry
    LIANG Chunlai, CHENG Linli, SHEN Jianzhong, ZHANG Yujie, ZHANG Suxia
    2009, 27 (6):  815-819. 
    Abstract ( 2359 )   [Full Text(HTML)] () PDF (193KB) ( 728 )  
    A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS) method for the determination of 5 polyether antibiotics (lasalocid, salinomycin, monensin, narasin and maduramicin) in chicken tissues was developed. The polyether antibiotics were extracted from chicken tissues with methanol. The extract was evaporated to dry, and redissolved in hexane, then cleaned up on a Sep-Pak Silica solid-phase extraction cartridge. The target drugs were eluted with 6 mL methylene chloride-methanol (90:10, v/v), and the eluate was collected and dried under a gentle stream of nitrogen gas, then the residue was dissolved with 1 mL acetonitrile (containing 0.1% formic acid) and analyzed by LC-MS/MS. The LC separation was performed on a Symmetry Shield reversed phase C18 bonded silica column with acetonitrile (containing 0.1% formic acid) - 0.1% formic acid (97:3, v/v) as mobile phase. The quantification was carried out by positive electrospray ionization and multiple reaction monitoring (MRM) mode. The validation was carried out on spiked chicken muscle (spiked at 0.1~1500 μg/kg) and chicken liver (spiked at 0.2~4500 μg/kg), the average recoveries of target drugs ranged from 71.6%~99.1% with intra-day relative standard deviations (RSDs) of 3.2%~10.7% and inter-day RSDs of 4.6%~14.7%. The limits of quantification (LOQs) in chicken muscle and liver were 0.1~1.0 μg/kg. The results demonstrated that the sensitivity, accuracy and precision of this method meet the requirements of veterinary drug residue analysis. The method is applicable to detect 5 polyether antibiotics in chicken muscle and liver.
    Separation and identification of 5 glycosidic flavor precursors in tobacco by ultra performance liquid chromatography- electrospray ionization tandem mass spectrometry
    WU Xinhua, ZHU Ruizhi, REN Zhuoying, WANG Kai, MOU Dingrong, WEI Wanzhi, MIAO Mingming
    2009, 27 (6):  820-824. 
    Abstract ( 2747 )   [Full Text(HTML)] () PDF (252KB) ( 706 )  
    A qualitative method for the identification of 5 main glycosidic flavor precursors in tobacco was developed by using ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI MS/MS) and gas chromatography-mass spectrometry (GC-MS). The glycosidic flavor precursors in tobacco were extracted with methanol, cleaned up with an XAD-2 column. The aglycones were later released by enzyme-mediated hydrolysis under the condition of pH 5. The 5 volatile aglycone moieties were identified by GC-MS standard spectra library. The precursor ions of glycosides were determined by using electrospray ionization mass spectrometry in negative ion mode, then the 5 glycosidic flavor precursors were identified by using product ion scan (MS2) finally, using UPLC-ESI MS/MS, separation and identification of 5 glycosidic flavor precursors were accomplished on an RP-C18 column in the multiple reaction monitoring (MRM) mode by using methanol and acetic acid-ammonium acetate aqueous solution as eluent. This work lays a foundation for the analysis of glycosidic flavor precursors without the standards by using liquid chromatography-mass spectrometry.
    Determination of sulfite in flue gas desulfurization with seawater by ion chromatography
    YIN Liqian, YUAN Dongxing, GUO Juan, LIU Xiyao
    2009, 27 (6):  825-828. 
    Abstract ( 2879 )   [Full Text(HTML)] () PDF (138KB) ( 819 )  
    The technology for flue gas desulfurization (FGD) with seawater is widely adopted by coal-fired power plants in coastal areas. SO2 in the flue gas is absorbed by alkaline seawater and transfered in aqueous phase as sulfite (SO2~3), and most SO2~3 is transformed to sulfate (SO2~4) after an aeration process. The remaining SO2~3 in the seawater discharged to sea area may be harmful to marine organism because of its biological toxicity, thus it is necessary to determine the concentration of SO2~3 in the seawater for desulfurization. In this study, the method of determination of SO2~3 in the seawater by ion chromatography was investigated. The separation was achieved on an IonPac AS14A column with 14 mmol/L NaOH-12 mmol/L Na2CO3 solution as the mobile phase at a flow rate of 1.2 mL/min, and the detection was performed by a pulsed amperometric detector. Formaldehyde was added as a protective agent when sampling because the SO2~3 is easy to be oxidized. To avoid the formation of Mg(OH)2 in the mobile phase with high pH value which might block the column, the Mg2+ in seawater was precipitated by NaOH solution (pH 12.0) before sample determination. The method showed good linearity within the range of 0~100 mg/L with an average recovery of 116.8%. The method detection limit (MDL) reached as low as 0.05 mg/L. The relative standard deviations (RSD) for seawater matrix samples spiked at levels of 7.5, 25.0 and 75.0 mg/L were 2.1%, 3.1% and 4.0% (n=9), respectively. The method has been applied for the determination of SO2~3 in flue gas desulfurization seawater with the advantages of being fast, sensitive and selective.
    Ion chromatographic analysis and mass spectrometric identification of complexes of metal and ethylene- diaminedisuccinic acid in plants and soils
    NIU Liyuan, SHEN Zhenguo
    2009, 27 (6):  829-834. 
    Abstract ( 2170 )   [Full Text(HTML)] () PDF (240KB) ( 646 )  
    The complexes of metal (Fe (III), Cu, Pb, Zn and Mn) and [S,S′]-ethylenediaminedisuccinic acid (EDDS)in plants and soils were determined by using ion chromatography and electrospray ionization mass spectrometry. The separation of metal-EDDS complexes was carried out using the Dionex IonPac AS11-HC column (250 mm×4.2 mm, 5 μm) with guard column. The mobile phase was 60 mmol/L ammonium nitrate solution at pH 6.5, the flow rate was 1.0 mL/min, and the detection wavelength was 260 nm. The mass spectrometry identification of metal-EDDS complexes was performed by using selected ion monitoring (SIM) mode. The results showed that method can be used for Fe(III)-, Pb-, Cu-EDDS complex determination and the detection limits of Fe(III)-, Pb- and Cu-EDDS complexes were 0.38, 0.54 and 0.18 μmol/L. and the recoveries were 99.6%, 100.6% and 97.5%, respectively. The method is simple, sensitive and suitable for either single or simultaneous analysis of Fe(III)-, Cu- and Pb-EDDS complexes in plants and soils.
    Fast separation and analysis of water-soluble vitamins in spinach by capillary electrophoresis with high voltage
    HU Xiaoqin, YOU Huiyan,
    2009, 27 (6):  835-839. 
    Abstract ( 2096 )   [Full Text(HTML)] () PDF (189KB) ( 785 )  
    In capillary electrophoresis, 0~40 kV (even higher) voltage can be reached by a connecting double-model high voltage power supply. In the article, water-soluble vitamins, VB1, VB2, VB6, VC, calcium D-pantothenate, D-biotin, nicotinic acid and folic acid in vegetable, were separated by using the high voltage power supply under the condition of electrolyte water solution as running buffer. The separation conditions, such as voltage, the concentration of buffer and pH value etc., were optimized during the experiments. The results showed that eight water-soluble vitamins could be baseline separated in 2.2 min at 40 kV applied voltage, 25 mmol/L sodium tetraborate buffer solution (pH 8.8). The water-soluble vitamins in spinach were quantified and the results were satisfied. The linear correlation coefficients of the water-soluble vitamins ranged from 0.9981 to 0.9999. The detection limits ranged from 0.2 to 0.3 mg/L. The average recoveries ranged from 88.0% to 100.6% with the relative standard deviations (RSD) range of 1.15%~4.13% for the spinach samples.
    Determination of four amino acids in tea by capillary zone electrophoresis and direct ultraviolet detection without derivatization
    WANG Qingping, ZHANG Lan, CHEN Guonan, LIN Jin-Ming
    2009, 27 (6):  840-844. 
    Abstract ( 2480 )   [Full Text(HTML)] () PDF (191KB) ( 598 )  
    Four important amino acids, arginine (Arg), tryptophane (Trp), phenylalanine (Phe) and tyrosine (Tyr) in tea samples with different fermentation processes were simultaneously determined by capillary zone electrophoresis (CZE) using direct ultraviolet detection (UV) at 190 nm. Under the conditions of 20 kV of separation voltage and 25 ℃ of temperature, Arg, Trp, Phe and Tyr were separated successfully within 8 min in 25 mmol/L sodium borate-boric acid (pH 10.0) with the detection limits of 5.0, 1.0, 0.3 and 0.5 mg/L for Arg, Trp, Phe and Tyr, respectively. The relative standard deviations (RSDs) of migration time (n=7) were all lower than 2.8% and the RSDs of peak electric current (n=7) were lower than 4.0%. The method was applied in the determination of Arg, Trp, Phe and Tyr in eleven tea samples. The results were satisfactory. This method can provide beneficial reference to evaluation quality of tea.
    Technical Notes
    Determination of dichloromethane and trichloromethane residues in ranitidine hydrochloride by headspace liquid phase microextraction coupled with gas chromatography
    SHEN Shuchang, YUN Dan, LI Fei
    2009, 27 (6):  845-848. 
    Abstract ( 5574 )   [Full Text(HTML)] () PDF (131KB) ( 884 )  
    A method for the determination of residual dichloromethane and trichloromethane in ranitidine hydrochloride by headspace liquid phase microextraction coupled with gas chromatography (GC) was developed. A homemade device was used to protect the organic drop. The effects of the nature of extraction solvent, extraction time, extraction temperature and microdrop volume on the extraction efficiency were investigated separately. The optimal experimental conditions were as follows: 2 μL of n-tridecane as extraction solvent, 30 min of extraction time, 60 ℃ of extraction temperature. The correlation coefficients of linear calibration curve were 0.9733 and 0.9724 within the concentration ranges of dichloromethane (1~10 μg/g) and trichloromethane (1~10 μg/g), respectively. The detection limits of dichlormethane and trichloromethane were 0.0273 μg/g and 0.0410 μg/g, respectively, the relative standard deviations were lower than 4.36% and 5.89%, and the recoveries of the method were 93.6%~102% and 98.1%~103%, respectively. The method is simple and reliable.
    Determination of fosetyl-aluminium by ion-pair reversed phase-high performance liquid chromatography with evaporative light scattering detection
    FAN Zhixian, JIA Shumin, Ding Ning, ZHAO Wenying, WANG Shujuan
    2009, 27 (6):  849-851. 
    Abstract ( 3150 )   [Full Text(HTML)] () PDF (99KB) ( 697 )  
    Ion-pair reversed phase-high performance liquid chromatography (RP-HPLC) with evaporative light scattering detection (ELSD) has been established for the analysis of fosetyl-aluminium and relevant impurities in technical or formulated substance. The method was achieved on a Symmetry Shield RP18 column by using n-butylamine as ion-pairing agent. The mobile phase was methanol-redistilled water containing 0.5% n-butylamine which was adjusted pH 5.0 with acetic acid (8:92, v/v) and the flow rate was set at 0.8 mL/min. The active ingredient fosetyl-aluminium was successfully separated from relevant impurities under the conditions. The calibration curve was linear in the range of 100~1200 mg/L. The average recoveries of two fortification levels (100 mg/L and 1000 mg/L) were 100.58% and 99.53%, and the relative standard deviations (RSDs) were 0.62% and 0.49%, respectively. The method is rapid, simple and accurate which provides another new and reliable means for the analysis of fosetyl-aluminium in its technical or formulated substance.
    Simultaneous determination of 9 water-soluble colorants in cosmetics by high performance liquid chromatography
    SUN Xiaoying, LI Ying, LIU Li, ZHANG Chen, LI Bin, LIANG Tongwen
    2009, 27 (6):  852-855. 
    Abstract ( 1867 )   [Full Text(HTML)] () PDF (137KB) ( 898 )  
    An analytical method based on high performance liquid chromatography with diode array detector (HPLC-DAD) has been established for the simultaneous determination of 9 water-soluble colorants (Solvent Green 7, Food Yellow 3, Food Red 17, Acid Yellow 1, Acid Red 33, Food Red 4, Food Red 1, Orange I, Acid Orange 7) in cosmetics. The different kinds of samples were treated with different preparation methods. The obtained liquid samples were analyzed by HPLC using a Diamonsil C18 column (250 mm×4.6 mm, 5 μm). Acetonitrile-potassium dihydrogen phosphate (KH2PO4) buffer solution (pH 6) was used as the mobile phase for gradient elution. The 9 water-soluble colorants were well separated within 15 min. The average recoveries (n=9) were from 85.33% to 100.2% with the relative standard deviations (RSDs) between 3.68% and 8.20%. The limits of detection (LOD) were in the range of 0.01~0.1 mg/L. The method is simple, rapid, accurate and suitable for the determination of 9 water-soluble colorants in cosmetics.
    Determination of acrylamide residue in cosmetics by isotope dilution-liquid chromatography-tandem mass spectrometry
    MA Qiang, WANG Chao, BAI Hua, WANG Xing, ZHANG Qing, XIAO Haiqing, YAN Yan, DONG Yiyang, WANG Baolin
    2009, 27 (6):  856-859. 
    Abstract ( 3177 )   [Full Text(HTML)] () PDF (144KB) ( 924 )  
    A comprehensive analytical method based on isotope dilution-liquid chromatography- tandem mass spectrometry (LC-MS/MS) has been developed for the determination of acrylamide residue in cosmetics. Water-soluble cosmetic sample was extracted with water, and the extract was centrifuged, then the upper solution was cleaned up by an Oasis HLB solid phase extraction cartridge. Oil-soluble cosmetic sample was extracted by liquid-liquid partition with n-hexane and water. The qualitative and quantitative analyses were carried out for the analyte in the multiple reaction monitoring (MRM) mode after the chromatographic separation on a Waters Atlantis T3 column (150 mm × 2.1 mm, 3 μm). The quantification was performed with 13C3-acrylamide as internal standard. The limit of quantification (LOQ) for acrylamide was 0.1 mg/kg. The mean recoveries were 87.7%~95.8% at the spiked levels of 0.1~1.0 mg/kg with the intra-day precision less than 10% and the inter-day precision less than 12%. The method is suitable for the determination of acrylamide in cosmetics.
    Determination of polymyxin E1 and polymyxin E2 in polymyxin E sulfate using micellar electrokinetic capillary chromatography
    YAN Yongna, WANG Lijuan, YANG Gengliang, HOU Wenxin, ZHANG Qiaoxia
    2009, 27 (6):  860-863. 
    Abstract ( 2401 )   [Full Text(HTML)] () PDF (187KB) ( 953 )  
    A method of micellar electrokinetic chromatography capillary (MECC) has been established for separating polymyxins E1 and E2 in polymyxin E sulfate and determining the contents of E1 and E2. Several factors including the running voltage, the type of surfactant, concentrations of Brij-35 (polyoxyethyleneglycol dodecyl ether), NaCl solution and acetonitrile, pH of phosphate were investigated. Under the optimum conditions (10 kV running voltage, phosphate buffer solution (0.01 mol/L, pH 4.1) containing 30 mmol/L Brij-35, 5%(v/v) acetonitrile, 0.167 mol/L NaCl), E1 and E2 were separated with the resolution of 1.94. The contents of E1 and E2 in polymyxin E sulfate were 67% and 32%, respectively. As an example, the relative standard deviations of the intra-assay and inter-assay of polymyxin E1 on the plate number and peak area were less than 5%. The method is simple, rapid, accurate, and reproducible.