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Chinese Journal of Chromatography
2013, Vol. 31, No. 8
Online: 28 August 2013

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Determination of ribavirin and amantadine in chicken by ultra performance liquid chromatography-tandem mass spectrometry YUN Huan, CUI Fengyun, YAN Hua, LIU Xin, HE Yue, ZHANG Zhaohui 2013, 31 (8):  724-728.  DOI: 10.3724/SP.J.1123.2013.01023 Abstract ( 1748 )   [Full Text(HTML)] () PDF (831KB) ( 293 )   A method for the determination of ribavirin and amantadine in chicken has been developed by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). After extracted by 1% (volume percentage) trichloroacetic acid solution-acetonitrile (1:1, v/v) and purified by a Supelco LC-SCX cartridge, the samples were loaded onto an Acquity UPLC BEH Hillic column (150 mm×2.1 mm, 1.7 μm)and separated with gradient elution. The electrospray was operated in the positive mode and the samples were monitored by the multiple reaction monitoring (MRM) mode. The limits of quantification (LOQs, S/N=10) of ribavirin and amantadine were 4.0 μg/kg. The calibration curves showed good linearity in the range of 10.0-100.0 μg/L, and the correlation coefficients (r2) were not lower than 0.99. When the spiked levels were 4.0, 8.0 and 20.0 μg/kg, the recoveries of ribavirin and amantadine in chicken ranged from 78% to 102.5%, with the relative standard deviations (RSDs) of 2.2%-7.6%. The results indicate that the method is simple, rapid, sensitive and suitable for the qualitative and quantitative analyses of ribavirin and amantadine in chicken samples.

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Fast screening of the artificial dyes in wine by liquid chromatography/hybrid linear ion trap-orbitrap mass spectrometry LI Yongle, ZHENG Yanjie, XIONG Cen, ZENG Yongting, CHEN Sujuan 2013, 31 (8):  729-733.  DOI: 10.3724/SP.J.1123.2013.01019 Abstract ( 1310 )   [Full Text(HTML)] () PDF (855KB) ( 358 )   A fast screening method was established for the simultaneous determination of 15 water-soluble artificial dyes in wine by liquid chromatography/hybrid linear ion trap orbitrap mass spectrometry (LC/LTQ-orbitrap MS) based on a self-established mass spectral database. The confirmations of these target dyes were processed by the accurate mass numbers, and the MS2 spectra marching to the self-established mass spectral database. The dyes in wine were purified by an anion-exchange column and separated by a BEH Phenyl column, then identified and quantified by LTQ-orbitrap MS. The results showed that the method detection limits of the target compounds were ranged from 0.00040 to 0.18 mg/L, and the average recoveries of the 15 compounds spiked at three concentrations were in the range of 43.1%-127% with the relative standard deviations less than 10%. The spiked sample had the matching scores higher than 98% to the second order mass spectra of the standard compounds in the database. The method is also suitable for screening the 15 dyes in wine without reference standards.

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Analysis of docosahexenoic acid in human blood using heterocyclic derivatization-gas chromatography-triple quadrupole mass spectrometry WANG Jing, WANG Dan, ZHANG Hua, PENG Xiaojun, DONG Junpu 2013, 31 (8):  734-738.  DOI: 10.3724/SP.J.1123.2013.01050 Abstract ( 1196 )   [Full Text(HTML)] () PDF (841KB) ( 282 )   A method was developed and validated for the analysis of docosahexenoic acid (DHA) in human blood by heterocyclic derivatization-gas chromatography coupled with triple quadrupole mass spectrometry (GC-MS/MS). 2-Amino-2-methyl-1-propanol (AMP) was used as the reaction reagent of DHA heterocyclic derivatization and the most optimal reaction conditions of this reaction were optimized. Multiple reaction monitoring and internal standard calibration curve were applied to detect DHA by GC-MS/MS. The linear range for the determination of DHA was 0.07-10 μg/mL (r2=0.9991). The limit of detection (S/N=2.8) was 0.02 μg/mL and the limit of quantification (S/N=10) was 0.07 μg/mL. The average recoveries of DHA at three spiked levels of 0.5, 1.5 and 2.5 μg ranged from 94.40% to 103.13% and the relative standard deviations (RSD) were in the range of 1.51%-3.16%. The method was simple, accurate, reliable and small amount of sample was required. It was suitable for detecting the contents of DHA in human blood.

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Determination of 30 organochlorine pesticides in animal-originated food products using combined purification by gel permeation chromatography and solid-phase extraction coupled with gas chromatography-mass spectrometry DU Juan, LÜ Bing, ZHU Pan, MIAO Hong, WU Yongning 2013, 31 (8):  739-746.  DOI: 10.3724/SP.J.1123.2013.01036 Abstract ( 1333 )   [Full Text(HTML)] () PDF (905KB) ( 285 )   A new analytical method was developed for the determination of 30 organochlorine pesticides (OCPs) in animal-originated food, including pork, chicken, fish and shrimp. The combined purification by gel permeation chromatography (GPC) and solid-phase extraction (SPE) were established by optimizing different fraction collection times. The detection conditions can be achieved by gas chromatography-mass spectrometry (GC-MS) using selective ion monitoring (SIM). Isotopic internal standards were used for the quantitative determination of the 30 OCPs. The sample pretreatment procedure was based on acetonitrile extraction and combined purification of GPC and Florisil SPE cartridge. The experimental results showed that the linear ranges for 30 OCPs were 5.0-500.0 μg/L, the correlation coefficients were better than 0.996, and the method detection limits (MDLs) of the 30 OCPs were 0.2-2.7 μg/kg. The spiked recoveries at three levels of 5.0, 10.0 and 20.0 μg/kg using pork, chicken, fish and shrimp samples as blank matrices were in the range of 55.0%-119.1%, the relative standard deviations (RSDs) were in the range of 0.4%-15.0%. The method has the advantages of wide linear range, high sensitivity and efficient clean-up procedure, and consistent with the demand of pesticide routine analysis.

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Determination of butene-fipronil residue in dry samples by multiple adsorption synchronous purification-gas chromatography-mass spectrometry DING Liping, GUO Jing, ZHENG Ling, CHEN Chuntian, CHEN Zhitao 2013, 31 (8):  747-752.  DOI: 10.3724/SP.J.1123.2013.01033 Abstract ( 1119 )   [Full Text(HTML)] () PDF (863KB) ( 211 )   A method was developed for the determination of butene-fipronil residue in dry samples by multiple adsorption synchronous purification (MASP)-gas chromatography (GC)-mass spectrometry (MS). After extracted with 1% acetic acid-acetonitrile, the samples were pretreated with MASP method including extraction, salting-out and purification procedures, and analyzed with GC-MS under the selected ion monitoring (SIM) mode, and then quantified by matrix-match standard solution with external standard method. The results showed good linearity in the range of 2-100 μg/L with the correlation coefficients (r2)not less than 0.999. The average fortified recovery of butene-fipronil in samples was found in the range of 92.2%-97.5% at three fortified levels from 2 to 10 μg/kg, with the relative standard deviations of 2.69%-5.21% (n=6). The limit of detection (S/N=3) for butane-fipronil was 2 μg/kg and the limit of quantification (S/N=10) was 6 μg/kg. The method is simple, rapid and accurate, and could be used for the routine analysis of butane-fipronil in dry samples. Meanwhile, the pyrolysis mechanism of butane-fipronil, as a new substance, is discussed.

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Application of general retention time formula for gradient liquid chromatography in the studies of ladder-like gradient elution SUN Xiaoli, HAO Weiqiang, WANG Junde, DI Bin, CHEN Qiang, ZHUANG Wei, YU Qiang, ZHANG Peipei 2013, 31 (8):  753-757.  DOI: 10.3724/SP.J.1123.2013.01018 Abstract ( 1426 )   [Full Text(HTML)] () PDF (824KB) ( 236 )   By not explicitly specifying the type of solvent strength model, the features of ladder-like gradient elution were studied based on the general retention time formula that was derived in our previous work. For the case where the solute is eluted at the slope of the ladder-like gradient, we derived the expression that connects the mobile phase composition (φR), at which the solute is eluted from the column, with the gradient slope (B). It was shown thatφR will increase with the increase of B in this case. For the case where the solute is eluted at the last isocratic segment of the ladder-like gradient, it was proven that the retention time (tR) will correlate linearly with the reciprocal of the gradient slope (1/B) when the initial and final mobile phase compositions are set to be constant. In experiments, by taking biphenyl as the sample, the values of retention time in isocratic and gradient elution were measured on a C18 column by using a mixture of methanol and water as the mobile phase. The experimental values were found to be well consistent with the theoretical values that were calculated from the expressions. These expressions will be helpful to understand the features of the ladder-like gradient in practice.

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Reversed-phase high performance liquid chromatography separation of 2-(fluorophenyl)-5-methylbenzoxazole and 2-(chlorophenyl)-5-methylbenzoxazole positional isomers WANG Min 2013, 31 (8):  758-762.  DOI: 10.3724/SP.J.1123.2013.01030 Abstract ( 1046 )   [Full Text(HTML)] () PDF (844KB) ( 223 )   The analytical method of 2-(fluorophenyl)-5-methylbenzoxazole ortho-, meta-, para-positional isomers and 2-(chlorophenyl)-5-methylbenzoxazole ortho-, meta-, para-positional isomers was developed with a commercial common liquid chromatography column. The separation was performed on an Inertsil ODS-SP C18 column (250 mm×4.6 mm, 5 μm) at 40℃ with a linear gradient elution by mobile phases of acetonitrile (A) (from 60% to 80% within 15 min) and water (B) at a flow rate of 1.5 mL/min. The samples were detected by a diode array detector at 310 nm. Good linearities were obtained in the range of 2-200 mg/L for the six isomers. The limits of detection (LODs) (S/N=3) of 2-(fluorophenyl)-5-methylbenzoxazole ortho-, meta-, para-isomers and 2-(chlorophenyl)-5-methylbenzoxazole ortho-, meta-, para-isomers were 0.0307, 0.0293, 0.0315, 0.0226, 0.0237, 0.0226 mg/L, respectively. The method provides not only a rapid detection method for the preparation of the isomers through hydrocarbon activation coupling reaction between the 5-methylbenzoxazole and fluorobenzene or chlorobenzene but also a reference for the separation and detection of 2-arylbenzoxazole isomers.

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Influence of pH value of mobile phase on phosphopeptide enrichment selectivity under hydrophilic interaction liquid chromatography mode by using Click OEG-CD matrix ZHAO Yanyan, GUO Zhimou, LI Xiuling, LIANG Xinmiao 2013, 31 (8):  763-768.  DOI: 10.3724/SP.J.1123.2013.03003 Abstract ( 888 )   [Full Text(HTML)] () PDF (1594KB) ( 165 )   The digest of the standard proteinα-casein was used as the objective to investigate the influence of pH value of mobile phase on phosphopeptide enrichment selectivity by using Click OEG-CD matrix. Disodium phenyl phosphate was primarily selected as the model sample. The results indicated that phosphate group was difficultly to be ionized when the pH value of mobile phase was below its pKa value. The retention of disodium phenyl phosphate on the Click OEG-CD matrix was not based on ion exchange interaction, leading to the weak retention. The influence of pH value (2, 4 and 6) of mobile phase under hydrophilic interaction liquid chromatography (HILIC) mode on phosphopeptide enrichment selectivity was investigated taking the digest of α-casein as a sample. Phosphopeptides could not be enriched on the matrix with the pH value of 2; phosphopeptides could be enriched on the matrix and the elution window was narrow with the pH value of 4; phosphopeptides could be enriched on the matrix while the elution window was broad with the pH value of 6. According to the investigation, Click OEG-CD matrix could be better applied in phosphopeptide enrichment.

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Preparation and application of solid phase extraction packing of zirconia microsphere coated with sulfonated crosslinked polystyrene SHEN Shuchang, LIU Yuhui, XIAO Xiaoxing 2013, 31 (8):  769-774.  DOI: 10.3724/SP.J.1123.2013.04015 Abstract ( 1148 )   [Full Text(HTML)] () PDF (3370KB) ( 294 )   Zirconia microsphere was prepared by polymerization-induced colloid aggregation (PICA) method and carbon-carbon double bond was grafted onto its surface by titanic acid ester coupling reagent. Poly(styrene-divinylbenzene) was synthesized by free radical polymerization by using styrene, divinylbenzene and carbon-carbon double bond on the microsphere surface in solution system, so the polymer was coated on the microsphere surface. After the benzene ring of the polymer was sulfonated, the cation exchange packing for solid phase extraction (SPE) was obtained. The material was characterized by Fourier transform infrared spectroscopy, scanning electron microscope and X-ray energy dispersive spectroscopy. Three herbicides of mesotrione, atrazine and acetochlor in water were determined by the SPE cartridge coupled with high performance liquid chromatography (HPLC). In the range of 0.5-3.0 mg/L, the relationships between the peak areas and mass concentrations of mesotrione, atrazine and acetochlor were linear with the correlation coefficients of 0.9936, 0.9925, 0.9919, respectively. The limits of detection were 5.41, 6.72 and 13.4 μg/L for mesotrione, atrazine and acetochlor, respectively. The results showed that the zirconium dioxide microspheres coated with polymer have diameters in the range of about 6 to 8 μm, the SPE cartridges of which have high adsorption rate for the targets.

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Determination of 17 ultraviolet-filters in cosmetics by high performance liquid chromatography MAO Xiqin, BIAN Haitao, QU Baocheng 2013, 31 (8):  775-780.  DOI: 10.3724/SP.J.1123.2013.02011 Abstract ( 1183 )   [Full Text(HTML)] () PDF (850KB) ( 276 )   An optimum HPLC method was developed for the simultaneous determination of 17 ultraviolet (UV)-filters in cosmetics, in which two UV-filters were included more than the 15 UV-filters specified in the Hygenic Standard for Cosmetics (HSC). Our research focused on the optimization of sample processing, chromatographic column, and mobile phase, in order to avoid the use of highly corrosive solvents as tetrahydrofuran (THF) and perchloric acid, which are used in the HSC method. The cosmetic sample was extracted by the mixed solution of THF/methanol/water. The target chemicals were separated on a Phenomenex PFP column (250 mm×4.6 mm, 5 μm) in gradient elution mode using water solution (containing 0.1% formic acid) and 20% methanol solution of isopropyl alcohol (containing 0.1% formic acid) as mobile phases. The detection wavelengths were set at 311 nm and 280 nm. The results of recovery tests and samples analysis indicated that the developed method can be used to simultaneously determine the 17 UV-filters in cosmetics, accurately and reliably. It is a more universal analytical method than the HSC method because common HPLC pump without improvement to adapt to corrosive THF, can be used. At the same time, the quantitative accuracy can be improved because baseline separation of all target chemicals was achieved.

Technical Notes

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Analysis of sialic acid in infant formulas using ultra performance liquid chromatography-triple quadrupole mass spectrometry XIE Honglei, LI Chun, LIU Ning 2013, 31 (8):  781-785.  DOI: 10.3724/SP.J.1123.2012.12051 Abstract ( 1332 )   [Full Text(HTML)] () PDF (833KB) ( 364 )   The method for analysing sialic acid in infant formulas by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has been established. Sialic acid in milk was released via acid hydrolysis, and purified by an HLB solid phase extraction cartridge. The UPLC separation was performed on an ACQUITY UPLCTM BEH HILIC column (50 mm×2.1 mm, 1.7 μm) utilizing a gradient elution program of acetonitrile and water (containing 0.1% formic acid) as the mobile phases at a flow rate of 0.25 mL/min. Injection volume and column temperature were set at 5 μL and 30℃, respectively. The identification and quantification were achieved by using electrospray ionisation (ESI)-MS/MS in positive ion mode and multiple reaction monitoring (MRM) mode. The linear range was from 0.05 to 5.0 mg/L for sialic acid and the correlation coefficient (R2) was greater than 0.99. The average recoveries spiked at the four concentration levels of 0.1, 0.5, 2.5 and 5.0 mg/L ranged between 84.3% and 98.9% with the relative standard deviations from 4.9% to 8.2%. The limit of detection was 0.01 mg/L. Therefore, this method has the characteristics of simple operation, high reproducibility and sensitivity. It can be widely applied to determine the total contents of sialic acid in infant formula, cow milk and human milk.

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Determination of alditols in wine by gas chromatography-mass spectrometry after acetate derivatization ZHOU Hongbin, XIONG Zhiyu, YU Yang, WAN Rong, LI Ping, SHEN Bo 2013, 31 (8):  786-790.  DOI: 10.3724/SP.J.1123.2013.01005 Abstract ( 1520 )   [Full Text(HTML)] () PDF (823KB) ( 379 )   The acetate derivatization of alditols for determining alditol level in wine by gas chromatography (GC)-mass spectrometry (MS) has been developed. The wine sample was mixed with pyridine and centrifuged at 5000 r/min at the temperature of 4℃ for 10 min. After filtration with organic phase membrane, the supernatant was derivatized with acetic anhydride, and then dehydrated with anhydrous sodium sulfate. The GC separation was performed on a DB-5MS capillary column. The alditols were determined by MS in selected ion monitoring (SIM) mode and quantified by external standard method. The calibration curves showed good linearities in the range of 0.019-1.25 mg/L except for lactitol (0.039-2.50 mg/L) with the correlation coefficients greater than 0.99. The limits of quantification (S/N=10) of erythritol, xylitol, D-mannitol, sorbitol, galactitol and lactitol were 0.17, 0.29, 0.43, 0.46, 0.47 and 2.88 mg/L respectively. The limits of detection (S/N=3) were 0.05, 0.08, 0.13, 0.14, 0.14 and 1.38 mg/L respectively. The recoveries of alditols spiked in the wine at two levels of 40 mg/L and 80 mg/L were ranged from 80.15% to 108.75% with the relative standard deviations (RSDs) of 2.16%-6.97%. The sensitivity, accuracy and precision of the method can meet the technical standard. The method can be applied to the rapid determination of alditols in wine.

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Determination of hexabromocyclododecane in coatings by gas chromatography-mass spectrometry WANG Hui, XUE Qiuhong, TAO Lin, YE Xiwen, LIANG Shengkang, LI Yanqiu, NIU Zengyuan 2013, 31 (8):  791-794.  DOI: 10.3724/SP.J.1123.2013.01014 Abstract ( 1705 )   [Full Text(HTML)] () PDF (812KB) ( 225 )   A method has been developed for the determination of hexabromocyclododecane (HBCD) in fire proof coatings by gas chromatography-mass spectrometry (GC-MS). The sample was extracted with dichloromethane and purified through an organic membrane before analysis with GC-MS. The characteristic fragments (m/z 157, 239, 319, 401) and the quantitative ion (m/z 239) were selected. With the optimized conditions, the good linear relationship was obtained between the peak area and the mass concentration of HBCD in the range of 5 to 100 mg/L with the correlation coefficient more than 0.999. The spiked recoveries in the coatings of acrylic and epoxy resins were 92.9%-116.3% with the RSDs not more than 8%. The LOD (S/N≥3) of HBCD was 30 μg/g, and the LOQ (S/N≥10) was 100 μg/g, which were much lower than the international maximum residue limit. The method is simple, quick, accurate and precise, which can meet the requirements of the European Commission Regulation (EC) No. 1907/2006 and Norway PoHS instruction (Prohibition on Certain Hazardous Substances in Consumer Products) for the determination of HBCD. It is suitable for the analysis of HBCD in fire proof coatings.

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Microfluidic evaporative light scattering detector coupled with capillary liquid chromatography and its application to Ginkgo biloba extract analysis ZHAO Hui, WANG Yuhong, LIU Fang, WANG Yan, GU Xue, YAN Chao 2013, 31 (8):  795-799.  DOI: 10.3724/SP.J.1123.2012.12043 Abstract ( 1788 )   [Full Text(HTML)] () PDF (1003KB) ( 207 )   A novel separation system of microfluidic evaporative light scattering detector( μELSD) coupled with capillary liquid chromatography (cLC) was built and applied to the separation and detection of herbal medicine Ginkgo biloba extract and its disperse tablet formulation. Compared with the traditional HPLC, this μELSD-cLC system consumed much less sample and solvent. Some key parameters were optimized. It was found that the higher the evaporization temperature of the drift tube, the higher S/N could be achieved. The mobile phase A was 0.05% (v/v) trifluoroacetic acid (TFA), and the mobile phase B was methanol containing 0.05% (v/v) TFA. The optimized gradient conditions were as follows: 0-10 min, 5%B-25%B; 10-25 min, 25%B-38%B; 25-35 min, 38%B; 35-40 min, 38%B-42%B; 40-55 min, 42%B-50%B. The complex herbal medicine Ginkgo biloba extract and its disperse tablet formulation were successfully separated. Four main therapeutic components (bilobalide and ginkgolide A, B, C) were finally separated and determined, which were terpene lactones with pretty weak UV absorption. The RSDs of the detected terpene lactones from different manufacturers were all no more than 2.42%, which proved this platform’s good analysis repeatability. The results showed the applicability of the platform to the analysis of complex traditional Chinese medicines.

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Determination of five endogenous hormones in wheat by high performance liquid chromatography ZHANG Yuqiong, ZHONG Yanlong, GAO Cuiyun, DONG Zhaorong, CHEN Na, WANG Meifang 2013, 31 (8):  800-803.  DOI: 10.3724/SP.J.1123.2013.01011 Abstract ( 1647 )   [Full Text(HTML)] () PDF (819KB) ( 545 )   A high performance liquid chromatographic (HPLC) method was developed to determine the five endogenous hormones including indole-3-acetic acid (IAA), abscisic acid (ABA), gibberellic acid (GA3), zeatin (ZT) and salicylic acid (SA) in wheat. The separation conditions were optimized, and methanol was chosen as the extraction solvent. Then the extract was extracted by petroleum ether and ethyl acetate, and purified with the Sep-Pak C18 column. The chromatographic conditions were as follows: Eclipse XDB-C18 reversed phase column (250 mm×4.6 mm, 5 μm), the flow rate of 1 mL/min, the injection volume of 10 μL, and the detection wavelength of 240 nm were used for the separation of SA from 14.5 min to 18 min, while the detection at 254 nm used for the separation of the others. Methanol (A) and acetic acid aqueous solution (pH 3.6) (B) were used as the mobile phases with the linear gradient set as follows: 0-7 min 20%A, 7-10 min 20%A-28%A, 10-17 min 28%A, 17-19 min 28%A-40%A, 19-35 min 40%A. The results showed that: the hormones were separated well with the recoveries of 96.9%-98%, and the RSDs were in the range of 1.54% to 2.29%. It is a reliable method for rapid, accurate separation and determination of the endogenous hormones in wheat.

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Simultaneous determination of monosaccharides, disaccharides, oligosaccharides and sugar alcohols in foods by high performance liquid chromatography with evaporative light-scattering detection DING Hongliu, LI Can, JIN Ping, YUAN Lihong, YAO Yongqing, CHEN Ying, LI Pei 2013, 31 (8):  804-808.  DOI: 10.3724/SP.J.1123.2013.01013 Abstract ( 1971 )   [Full Text(HTML)] () PDF (832KB) ( 535 )   A simple and efficient method was established based on high performance liquid chromatography (HPLC) to separate and detect thirteen analytes of monosaccharides, disaccharides, oligosaccharides and sugar alcohols (xylose, fructose, glucose, sucrose, maltose, lactose, 1-kestose, nystose, 1F-fructofuranosyl nystose, erythritol, mannitol, xylitol, maltitol) in foods. The separation was performed on an NH2 column with the gradient elution of acetonitrile-water as the mobile phases. The analytes were detected by an evaporative light-scattering detector (ELSD). All the thirteen sugars had good linearities within 0.1-5 g/L with the correlation coefficients between 0.9901-0.9996. The limits of detection (LOD) were all less than 0.1 g/L. The precisions of the method expressed as RSDs were in the range of 2.69%-7.21%. The recoveries of the thirteen analytes spiked in real samples ranged from 96.1% to 105.2%. This method was applied to the actual sample testings and the results showed the food labels were greatly different from the actual compositions.

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Determination of three phenolic compounds in water samples by solid phase extraction with microemulsion liquid chromatography QIU Xiuzhen, GUO Huishi, CHEN Buqing 2013, 31 (8):  809-812.  DOI: 10.3724/SP.J.1123.2013.01029 Abstract ( 1250 )   [Full Text(HTML)] () PDF (800KB) ( 192 )   A method for the determination of phenol, bisphenol A (BPA), 2,4-dichlorophenol in water samples based on solid-phase extraction with microemulsion liquid chromatography(MELC) was established. The water sample was acidified, and then cleaned-up by a C18 solid-phase extraction cartridge. The separation was carried out on an Inertsil C18 (150 mm×4.6 mm, 5 μm) with a gradient elution using a microemulsion (consisting of 3.0% sodium dodecyl sulfate (SDS), 6.0% butyl alcohol, 0.8% n-heptane, 90.2% (water+0.5% acetic acid)) and acetonitrile as mobile phases at a flow rate of 1.0 mL/min and a detection wavelength of 280 nm. The detection limits (S/N=3) of phenol, BPA, 2,4-dichlorophenol were 0.74, 8.0, 8.0 μg/L, respectively. Good linearities were achieved for the target compounds over the range of 0.1-10 mg/L. The spiked recoveries of three phenolic compounds in blank water samples were 82.7%, 87.8%, 82.6% for phenol, BPA, 2,4-dichlorophenol respectively. The recoveries of target compounds in real water samples ranged from 85.7% to 113.2%. The developed method is simple, selective, sensitive and applicable for the analysis of environmental water samples.

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Preparation of thrombin affinity chromatography media WANG Xiongfei, ZHANG Yujie, YE Jing, LUO Zhiqiang, ZHAN Xueyan, YUAN Ruijuan 2013, 31 (8):  813-816.  DOI: 10.3724/SP.J.1123.2013.01024 Abstract ( 983 )   [Full Text(HTML)] () PDF (792KB) ( 197 )   The preparation of thrombin affinity chromatography media is described in this paper. First, the thrombin affinity chromatography media was prepared through thrombin coupled with cyanogen bromide activated agarose. And then the enzyme activity of thrombin on the coupled media was measured by chromogenic substrate method. The conditions were confirmed based on the enzyme activity of thrombin on the coupled media. The optimum conditions were as follows: the use of Na2CO3-NaHCO3 (containing 0.5 mol/L NaCl) solution of pH 8.3 as the reaction solution, 200 U thrombin per 1 g agarose, and reaction for 10 h at room temperature. The prepared affinity chromatography media had good stability, on which 70.6% of the enzyme activity of thrombin existed after 40 days’ storage. The thrombin affinity chromatography media can be widely applied in the screening and purification of thrombin inhibitors in natural products.