Chinese Journal of Chromatography

Applications of microextraction techniques in environmental analysis

WANG Jincheng, JIN Jing, XONG Li, CHEN Jiping

2010, 28 (1): 1-13.

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Microextraction techniques are green sample pretreatment techniques emerging in recent years. It is easy to operation and friendly to environment and has been widely used in the fields of environment, medicine and food. This review briefly introduces the applications of solid-phase microextraction (SPME) and liquid-phase microextraction (LPME) in the analysis of environmental pollutants.

Applications of ionic liquids in chromatographic analysis and determination of ionic liquids by chromatography

GAO Wei, YU Hong, ZHOU Shuang

2010, 28 (1): 14-22.

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As a kind of excellent solvent, ionic liquids have received more attentions. Because of the special physical and chemical properties of ionic liquids, ionic liquids have been more widely used in chromatography. This paper summarizes the applications of ionic liquids in gas chromatography, liquid chromatography and capillary electrophoresis, which include ionic liquids used as stationary phase in gas chromatography, stationary phase and mobile phase additive in liquid chromatography and electrolyte additives in capillary electrophoresis. The determination of ionic liquids by chromatography has also been introduced.

Rapid simultaneous determination of 42 psychoactive drugs and their metabolites in human plasma and urine by ultra performance liquid chromatography-tandem mass spectrometry

ZHANG Xiuyao, CAI Xinxin, ZHANG Xiaoyi

2010, 28 (1): 23-33.

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A rapid method for the simultaneous determination of 42 psychoactive drugs and their metabolites (barbitals, benzodiazepines, tricyclic antidepressants, phenothiazines, etc.) in human plasma and urine was developed using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). After a simple protein precipitation step, the analysis of the drugs and the metabolites was achieved on an Acquity UPLC BEH C18 column by using the gradient elution with ammonium acetate and methanol-acetonitrile (1:1, v/v) as the mobile phases, and detected by electrospray ionization-tandem mass spectrometry in the multiple reaction monitoring (MRM) mode operated simultaneously in both positive and negative modes by rapid switching, and quantified by matrix-match standard solution. The average recoveries were 60.2%~125% and 64.5%~126% for the drugs in plasma and urine except those of perphenazine, thioridazine and chloropromazine in plasma were 37.6%~57.5%, 36.3%~48.3%, 52.4%~67.4%, respectively; trazodone and diazepam in urine were 100%~142% and 108%~177%, respectively. The relative standard deviations (RSDs) of all the drugs in plasma and urine were within 0.8%~26% and 2.6%~18% (n=6), respectively. The detection limits of the 4 barbitals ranged from 20 to 100 mg/L and those of the other drugs ranged from 0.05 to 2.0 mg/L. The method is simple, selective and sensitive to detect drugs for both clinical and forensic purposes.

Comparison of extracted proteins of human stomach tumor and normal tissues with liquid chromatography-multistage mass spectrometry

LUO Fuwen, TAO Dingyin, ZHAO Peng, ZHANG Lingyi, JIA Yujie, ZHANG Weibing

2010, 28 (1): 34-37.

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Screening of tumor markers by proteomic technology is the research focus and key of early diagnosis of stomach cancer study. Aiming at the complexity of the extracted proteins from biological tissue, reversed-phase high performance liquid chromatography (RP-HPLC) was employed as one of the most efficient chromatographic methods. Based on the difference of hydrophobicity, RP-HPLC separation was performed to reduce the complexity of stomach cancer tissue and normal tissue samples, separately. By comparing the chromatograms, different components were collected. The fractions with the retention times from 45 min to 47 min were digested and identified by liquid chromatography-multistage mass spectrometry (LC-MS/MS). Nine common proteins were found in both tumor tissue and normal tissue. Six specific proteins were screened in normal tissue and seventeen specific proteins were found in tumor tissue under the same conditions. Two proteins with higher abundance in tumor tissue were selected for further investigation. These proteins provide more information for future drug target and drug pathway research by the analysis of biological information.

Determination of ten sedative residues in pork and kidney by ultra performance liquid chromatography-tandem mass spectrometry

SUN Lei, ZHANG Li, XU Qian, WANG Shuhuai, WANG Xia

2010, 28 (1): 38-42.

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An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)method was established for the determination of methaqualone, chloropromazine, promethazine, diazepam, nitrazepam, oxazepam, temazepam, midazolam, triazolam and zolpidem residues in pork and kidney. After enzymolysis, the samples were extracted by ethyl acetate and tert-butyl methyl ether, separately. The separation of the ten sedatives was performed on a Waters Acquity UPLC system with a BEH C18 column. The mobile phases were acetonitrile (containing 0.1% formic acid) and water (containing 0.1% formic acid) at a flow rate of 0.3 mL/min. The electrospray was operated in the positive ionization mode and the ten sedatives were identified by multiple reaction monitoring (MRM) mode. The method of matrix-matched standard solution was adopted as the quantitative method. The calibration curves showed good linearity within the concentrations of 2~100 μg/L with the correlation coefficients r＞0.998. The limits of detection of the ten sedatives were 0.5 μg/kg, and the limit of quantification was 1 μg/kg. The recoveries of the ten sedatives were 64.5%~111.4% at the spiked levels of 2, 5 and 10 μg/kg. The relative standard deviations of intra- and inter-day coefficients of variation were both less than 15%. This method is simple, sensitive and accurate in the determination of sedative residues.

Simultaneous determination of rimonabant and orlistat illegally added in the weight-loss functional foods by high performance liquid chromatography-tandem mass spectrometry

MA Wei, MA Qiang, FU Li, MA Liqing, WANG Haibo, LIU Caiyun, TANG Yingzhang

2010, 28 (1): 43-48.

Abstract ( 2466 ) [Full Text(HTML)] ()

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A sensitive and selective analytical method based on high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has been developed for the simultaneous determination of rimonabant and orlistat in weight-loss functional foods. After the foods were extracted under accelerated solvent extraction, the HPLC separation was performed on a Waters Atlantis T3 column (150 mm × 2.1 mm, 3 μm) with a linear gradient elution program of methanol and 10 mmol/L ammonium acetate as the mobile phase. Electrospray ionization was applied and operated in the positive ion mode. The results showed that the limits of detection for the rimonabant and orlistat were 0.5 mg/kg. The calibration curves showed good linearities for rimonabant and orlistat in the range of 0.5~100 μg/L, and the correlative coefficients were 0.9989 and 0.9994, respectively. The mean recoveries at the 3 spiked levels (2, 5, 10 mg/kg) were 80.5%~102.1% with the intra-day precision less than 6% and the inter-day precision less than 8%. The work studied the mass spectrum characterization of the 2 drugs and speculated on the fragmentation pathways. The method is sensitive, reproducible and adapts to the determination of rimonabant and orlistat in different weight-loss functional foods.

Component analysis of a new anabolic androgenic steroidand its monitoring research in human urine

QIU Lijun, SHANGGUAN Liangmin, LIU Wei, CHEN Guonan, ZHANG Lan

2010, 28 (1): 49-53.

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A new oral drug containing an unknown anabolic androgenic steroid (AAS) was studied. The principal constituent of the unknown anabolic hormone was studied by infrared spectrum (IR), nuclear magnetic resonance spectroscopy (1H NMR), ultraviolet spectroscopy (UV), and mass spectroscopy (MS). It was inferred to be methyl-1-testosterone (M1T,17β-hydroxy-17α-methyl-5α-androst-1-en-3-one) which was just added to the prohibited list in 2006. In addition, a monitoring, screening and confirmation of methyl-1-testosterone was established. The detection limit （S/N=3）was 2 ng/mL, and the limit of quantification （S/N=10） was 10 ng/mL. The relative standard deviation was 9.8% (n=7) for the determination of pretreated urine sample with internal standard. This method was successfully applied in the identification of M1T positive urine. The excretion curve of M1T in human urine is described. It is a significant work for the discovery, determination and monitoring of the new AAS.

Determination of dimethyl fumarate in leather and textiles by gas chromatography-tandem mass spectrometry with solid phase extraction

ZHAO Yang, QI Xiaoxia

2010, 28 (1): 54-58.

Abstract ( 3303 ) [Full Text(HTML)] ()

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An effective method for the determination of dimethyl fumarate (DMF) in leather and textiles by gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed. Samples of leather or textiles were extracted with ethyl acetate and concentrated, DMF was separated on a VF-5ms column and analyzed by GC-MS/MS after solid phase extraction (SPE) process. The result shows that this method is sensitive, accurate and reliable. The linear relationship was perfect and the interference with background signal was further eliminated after pretreatment, SPE and GC-MS/MS analytical conditions were optimized. The average recoveries of DMF in leather and textiles at three levels ranged from 84% to 93%, the relative standard deviations (n=6) were lower than 7.2%, the limits of detection in the range from 0.012 to 0.039 mg/kg (S/N=3), the correlation coefficient was 0.9990 over the range 0.05~100 mg/L. It has been applied to routine determination of DMF in leather and textiles with satisfactory results.

Determination of glyoxal and glyoxalic acid in aldehyde solution by high performance liquid chromatography

ZHU Yamei, CUI Qun, WANG Haiyan

2010, 28 (1): 59-63.

Abstract ( 3629 ) [Full Text(HTML)] ()

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The hydrazones have the absorption in the ultraviolet-visible (UV-vis) spectral region. The hydrazones can be formed by the reaction of aldehyde group and dinitrophenylhydrazine (DNPH) in acidic solution. The determination of glyoxal and glyoxalic acid in aldehyde solution was performed by high performance liquid chromatography (HPLC). The proper derivatization conditions were as follows: the reaction temperature of 70 ℃, the pH of the system of 1.75; the molar ratio of DNPH to carbonyl of 6, the reaction time of 150 min. The saturated concentration of glyoxal dihydrazone in acetonitrile solution at pH 1.75 and 20 ℃ was 20.2 mg/L. The standard curves for glyoxal and glyoxalic acid both had good linear relations in the ranges of 2~20 mg/L and 10~100 mg/L, respectively. The glyoxal and glyoxalic acid contents in the solution of oxidation of acetaldehyde to glyoxal by nitric acid were determined by this method, the repeatabilities of analysis results were excellent and the relative error compared to chemical analysis of glyoxal was 1.77%. The spiked recoveries of glyoxal and glyoxalic acid were 99.6%~103.3% and 98.1%~102.4%, respectively. The method is simple, accurate and efficient for determining aldehydes and dicarbonyl compounds.

Simultaneous determination of five effective components in Sijunzi bolus using high performance liquid chromatography-evaporation light scattering detection

LI Chunying, ZHANG Xiaojun

2010, 28 (1): 64-67.

Abstract ( 2060 ) [Full Text(HTML)] ()

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A high performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of lobetyolin, pachymic acid, glycyrrhizic acid, atractylenoide III and atractylenolideI in Sijunzi bolus. The separation was performed on an HIQ SIL C18 V column (250 mm×4.6 mm, 5 μm) with 0.5% acetic acid-methanol as the mobile phase of gradient elution at a flow rate of 1.0 mL/min. The detection was performed with an evaporation light scattering detector (ELSD) and the sample volume was 10 μL. The temperature of drift tube and heating grade of nebulizer was respectively set at 55 ℃ and 60% at 0.2 MPa of pressure. Nitrogen gas was used as carrier gas. Under the optimized conditions, there were good linear relationships between the logarithm values of mass concentration and the peak areas of lobetyolin, pachymic acid, glycyrrhizic acid, atractylenoide III and atractylenolide I in the ranges of 0.076~1.21, 0.048~0.76, 0.153~2.45, 0.045~0.72 and 0.098~1.56 g/L, respectively. The recoveries of the five components were between 97.13% and 100.25%, the relative standard deviations (RSDs) were between 1.23% and 2.44%. This method is simple, rapid, accurate and suitable for the quality control of Sijunzi bolus.

Preparative isolation and purification of ergosterol from a strain of Paecilomyces hepialid by high-speed counter-current chromatography

ZHANG Nengsheng, WANG Jinbin, WANG Xiaoyan, WANG Xiaodong, HU Fenglin

2010, 28 (1): 68-72.

Abstract ( 2327 ) [Full Text(HTML)] ()

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To develop an effective and rapid method for the preparation of ergosterol from a strain of Paecilomyces hepialid, the ethyl acetate extract of the mycelia was injected into a high-speed counter-current chromatograph (HSCCC) directly, and eluted with different solvent systems. The result showed that the solvent system composed of n-hexane-ethyl acetate-methanol-water (6:1.7:6:0.3, v/v/v/v) was the best. The lower phase was used as the mobile phase and performed at a flow rate of 2 mL/min, while the apparatus rotated at 850 r/min, and detected at 280 nm. The prepared ergosterol was identified with ultraviolet detection (UV), high resolution mass spectrometer (HRMS) and standard, and its purity was 99.2% analyzed by high performance liquid chromatography. The established method is relatively simple, fast, and suitable for the large-scale isolation and separation of ergosterol.

Determination of 15 volatile organic compound residues in cosmetics by headspace gas chromatography

XU Yinghua, ZHU Binghui, ZHONG Xiuhua, LI Shaoxia

2010, 28 (1): 73-77.

Abstract ( 2768 ) [Full Text(HTML)] ()

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A headspace gas chromatography (HS-GC) method was developed for the rapid determination of multi-mixture of 15 residual volatile organic compounds in cosmetics. The experimental conditions of HS-GC such as headspace temperature, headspace time and the analytical conditions of GC were optimized. Cosmetic samples were extracted and cleaned-up by headspace at 60 ℃ for 30 min, determined by GC-flame ionization detector (FID) and quantified by external standard method. The 15 poisonous volatile organic compounds were separated efficiently from impurities with high sensitivity and reproducibility. The relative standard deviations (RSDs) were less than 5%, the recoveries were from 62.8%~116%, the linear range was 0.002~2.0 mg/L with a good linear correlation coefficient (r＞0.999) and the limits of detection were 0.09~0.68 mg/kg. By means of the above developed HS-GC method, 15 residual volatile organic compounds in cosmetics were detected accurately and simultaneously in a single sample injection. The method is accurate, simple, rapid, and is suitable for the trace analysis of multi-mixture of residual volatile organic compounds in various cosmetics.

Separation of derivatized aliphatic aldehydes in beverage by nonaqueous capillary electrophoresis

BAI Xinwei, WANG Yanbao, ZHAO Huaixin, SUN Zhiwei, XIA Lian, FU Yanyan, SUO Yourui, LI Yulin, YOU Jinmao,

2010, 28 (1): 78-83.

Abstract ( 2439 ) [Full Text(HTML)] ()

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A simple and mild method for the separation of aliphatic aldehydes based on a condensation reaction with 9,10-phenanthrenequinone as labeling reagent with nonaqueous capillary electrophoresis has been developed. The detection was performed with a diode array detector (DAD). A 58.5 cm (50 cm effective length)×50 μm i. d. untreated fused-silica capillary was used. To optimize the conditions, the background electrolyte concentration, column temperature, voltage and other factors were evaluated. The results indicated that the buffer concentration had a great impact on the separation, but the influences of temperature and added additives on the resolution were not obvious. The optimized conditions were as follows: 80 mmol/L ammonium acetate, 1.4 mol/L acetic acid, voltage of 28 kV, column temperature of 20 ℃ and DAD detection at 254 nm. The samples were introduced atmospherically with the injection at 5 kPa (50 mbar) for 8 s. The results indicate that seven aliphatic aldehyde derivatives and actual samples can be achieved baseline resolution under the proposed conditions.

Determination of dicofol residue in eel by gas chromatography-mass spectrometry

SU Jianfeng, CHEN Jing, CHEN Jinxing, ZHONG Maosheng, ZHANG Guangjun, LIU Jianjun,

2010, 28 (1): 84-88.

Abstract ( 2471 ) [Full Text(HTML)] ()

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A method was developed and applied to determine the residual dicofol in eel by gas chromatography-mass spectrometry (GC-MS). The residue was extracted from homogenized tissue with acetonitrile-water assisted by n-hexane, separated with liquid-liquid partition. A part of the supernatant was purified using solid phase extraction (Florisil column) prior to the GC-MS analysis. The determination was performed in selected ion monitoring (SIM) mode with the external calibration for quantitative analysis. Under the optimized conditions, the quantification limit of the method (S/N=10) was lower than 0.01 mg/kg. The recovery of the method for the spiked standard at the concentration of 0.01~0.1 mg/kg was 91%~105% with the relative standard deviation (RSD) of 4.3%~6.1%. The method is easy, fast, and more sensitive. The method can meet the requirement of the determination of dicofol in eel.

Determination of α-arbutin, β-arbutin and niacinamide in cosmetics by high performance liquid chromatography

CHENG Peng, CHEN Meilan, ZHU Yan,

2010, 28 (1): 89-92.

Abstract ( 2778 ) [Full Text(HTML)] ()

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A high performance liquid chromatography (HPLC) method for the determination of two optical isomers of arbutin (α-arbutin and β-arbutin) and niacinamide in cosmetics was developed. The samples were extracted by the mixture of salt water and chloroform (2:1, v/v). The separation was performed on an ODS-BP column (200 mm×4.6 mm, 5 μm, Elite) with methanol-water (10:90, v/v) as the mobile phase at a flow rate of 0.5 mL/min and 25 ℃. The detection wavelength was set at 220 nm and the sample injection volume was 20 μL. There were good linear relationships between the mass concentration and the peak areas of α-arbutin, β-arbutin and niacinamide in the ranges of 0.07~50, 0.06~50 and 0.05~50 mg/L, respectively. The relative standard deviations (RSDs, n=7) of α-arbutin, β-arbutin and niacinamide were 1.65%, 1.73% and 1.33%, respectively. The proposed method has been applied for the determination of α-arbutin, β-arbutin and niacinamide in cosmetics with recoveries of 91.7%~109.6%. This method is rapid, simple and suitable for the detection of whitening ingredients in cosmetic.

In vitro dissolution profile comparison of an anti-migraine combinational drug in dosage form

HIREMATH Vijay Basayya, KALIAPERUMAL Krishna, BHOJRAJ Suresh, NANJAN Mulla Joghee

2010, 28 (1): 93-99.

Abstract ( 1871 ) [Full Text(HTML)] ()

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A novel in vitro dissolution profile was developed for formulated drug in combinational form containing naproxen sodium (NAP) and sumatriptan succinate (SUMA). This study was performed to understand the dissolution of the drug in the physiological temperature and pH. Dissolution testing was performed using USP 29 type II testing apparatus rotating at 50 r/min, in 900 mL deaerated buffer （pH 1.2, 4.5 and 6.8） which was maintained at (37±0.5) ℃. Quantification was performed using a developed and validated high performance liquid chromatographic (HPLC) method. Aceclofenac (ACE) was used as internal standard. SUMA, ACE and NAP were eluted at 4.8, 5.7 and 7.9 min, respectively. As expected for enteric coated immediate release (IR) tablets, the dissolution of NAP and SUMA was rapid and essentially complete within 2 h using phosphate buffer (pH 6.8). The comparison of the dissolution profiles was realized by model independent approach using a difference factor (f1), similarity factor (f2) and dissolution efficiency (DE). Statistical results showed the profiles were similar to the reference and the test products. Hence, this method demonstrated to be adequate for in vitro studies of NAP and SUMA in the combinational dosage form, since there is no official monograph, collaborating to the official codes.

Recent important development in chromatography

ZOU Hanfa

2010, 28 (1): 100-101.

Abstract ( 1548 ) [Full Text(HTML)] ()

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