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Determination of petroleum sulfonates in crude oil by column-switching anion-exchange chromatography

Chinese Chemical Letters 2008年第2期19卷 219-222页

作者： Liang Zhao Xu Long Cao Hong Yan Wang Xia Liu Sheng Xiang Jiang Key Laboratory for Natural Medicine of Gansu Province Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China Graduate School of the Chinese Academy of Sciences Chinese Academy of Sciences Beijing 100039 China Geological and Scientific Research Institute Shengli Oilfield SINOPEC Dongying 257015 China

A column-switching anion-exchange chromatography method was described for the separation and determination of petroleum monosulfonates （PMS） and petroleum disulfonates （PDS） in crude oil that was simply diluted with the dichloromethane/methanol （60/40）. The high performance liquid chromatography （HPLC） system consisted of a clean-up column and an analytical column, which were connected with two six-port switching valves. Detection of petroleum sulfonates was available and repeatable. This method has been successfully applied to determine PMS and PDS in crude oil samples from Shengli oil field.

关键词： Petroleum sulfonate Determination Anion-exchange chromatography column-switching Crude oil

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Development of simple HPLC/UV with a column-switching method for the determination of nicotine and cotinine in hair samples

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Health 2013年第4期5卷 687-694页

作者： Masayoshi Tsuji Yayoi Mori Hideyuki Kanda Teruna Ito Tomoo Hidaka Takeyasu Kakamu Tomohiro Kumagai Takehito Hayakawa Yoneatsu Osaki Tetsuhito Fukushima Department of Epidemiology and Public Health School of Medicine Yokohama City University Yokohama Japan Department of Hygiene and Preventive Medicine School of Medicine Fukushima Medical University Fukushima Japan Division of Environmental and Preventive Medicine Department of Social Medicine Faculty of Medicine Tottori University Yonago Japan

Nicotine and cotinine in hair are good biomarkers for assessing long-term exposure to smoking. However, analytical devices such as GC/MS are associated with high cost and are not widely used. HPLC/UV is used widely in laboratories, but is unsuitable for measurement of minor constituents, except when using the column-switching method. Thus, we aimed to establish a simple, inexpensive and sensitive method based on HPLC/UV with column switching for measuring nicotine and cotinine in hair. First, we compared the presence and absence of a column selection unit. We then measured amounts of nicotine and cotinine in hair samples collected from the general population, and compared both the corresponding levels and the detection limits with those in previous studies. Finally, initial and running costs of HPLC/UV were compared with other analytical methods. As one of the results, the areas of nicotine and cotinine measured by HPLC/UV with column-switching method were 12.9 and 16.9 times greater, respectively, than those without the column-switching method. The amount of nicotine and cotinine in hair was significantly correlated to number of cigarettes smoked per day (r = 0.228, p = 0.040). In addition, the HPLC/UV method showed similar sensitivity and detection limit (nicotine, 0.10 ng/mg;cotinine, 0.08 ng/mg) as reported in previous studies. The cost of the HPLC/UV method is lower than that of other analytical methods. We were able to establish a low-cost method with good sensitivity for measuring nicotine and cotinine in hair. The HPLC/UV with a column-switching method will be useful as a first step in screening surveys in order to better understand the effects of smoking exposure.

关键词： HPLC/UV column-switching Method Nicotine Hair Cotinine

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Construction of on-line supercritical fluid extraction with reverse phase liquid chromatography–tandem mass spectrometry for the determination of capsaicin

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Chinese Chemical Letters 2019年第1期30卷 99-102页

作者： Naoki Hamada Yuki Hashi Satoshi Yamaki Yanli Guo Lin Zhang Haifang Li Jin-Ming Lin Beijing Key Laboratory of Microanalytical Methods and Instrumentation MOE Key Laboratory of Bioorganic Phosphorous Chemistry & Chemical BiologyDepartment of Chemistry Tsinghua University China MS Center Shimadzu (China) Co. Beijing Branch

A novel on-line system composed of supercritical fluid extraction(SFE), dilution line and reverse phase liquid chromatography/mass spectrometry(RPLC/MS) was constructed for on-line extraction and reverse phase separation of some fat-soluble components in foods. Three columns including a trap column,concentration column and analytical column were used for trapping the fat-soluble components, on-line enrichment and reverse phase separation, respectively. Capsaicinoids were on-line extracted by a CO_2 supercritical fluid, then concentrated and separated by using the C_(18) columns, finally detected by mass spectrometry(MS). Capsaicin eluted at 10.1 min and limit of detection(LOD, S/N=3) for the standard solution is 0.55pg. The linearity was calculated with a value of coefficient of determination(R^2)≥0.998 in the range of 1.1–8.5 ng. Concentrations of capsaicin in the green, yellow, and red bell peppers were determined to be 60.33 ng/g, 31.79 ng/g, 35.38ng/g, respectively.

关键词： Supercritical fluid extraction Liquid chromatography-mass spectrometry column-switching system Capsaicin

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