Shin Ho-Sang, Ahn Hye-Sil, Lee Byung-Hoon
Department of Environmental Education, Kongju National University, Kongju, Republic of Korea.
J Mass Spectrom. 2007 Sep;42(9):1225-32. doi: 10.1002/jms.1255.
The derivatization method of thiazolidine-4-carboxylic acid (TZCA) and methyl-thiazolidine-4-carboxylic acid (Me-TZCA) in urine with alcohol/chloroformate was achieved. TZCA and Me-TZCA were derivatized in one step in urine with ethyl chloroformate in 1 min at room temperature. The derivatives of TZCA and Me-TZCA had very good chromatographic properties and offered very sensitive response for gas chromatography-electron impact ionization-mass spectrometry (GC-EI-MS). On the basis of derivatization, the method for simultaneous determination of TZCA and Me-TZCA in human urine was developed. Deuterated Me-TZCA (Me-TZCA-d(4)) was synthesized as the internal standard (IS) for the analysis of urine samples. TZCA and Me-TZCA were derivatized and extracted from urine at pH 9.5 with toluene, and then the dried extract was dissolved with 100 microl ethyl acetate and injected in GC/MS system. The recoveries of TZCA and Me-TZCA were about 102 and 103%, respectively, at the concentration of 0.05 mg/l. The method detection limits (MDL) were 1.0 and 0.5 microg/l, respectively, for TZCA and Me-TZCA in 1 ml human urine. The coefficients of variation of TZCA and Me-TZCA were less than 6% at the concentrations of 0.05 and 0.2 mg/l, respectively. To assess the formation of TZCA during inhalation with formaldehyde (FA) (about 3.1 and 38.1 ppm FA in air), urine samples from rats were taken during 3 days after initiation of treatment. The mean amount of TZCA determined was 0.07 mg/l in control group and 0.18 mg/l during treatment with 3.1 ppm. The TZCA levels increased up to about 1.01 mg/l during treatment with 38.1 ppm. It is planned to study whether urinary TZCA can be used as an indicator in the biological monitoring of exposure to FA.
实现了用乙醇/氯甲酸酯对尿液中的噻唑烷 - 4 - 羧酸（TZCA）和甲基 - 噻唑烷 - 4 - 羧酸（Me - TZCA）进行衍生化的方法。在室温下，TZCA和Me - TZCA在尿液中与氯甲酸乙酯一步反应1分钟即可完成衍生化。TZCA和Me - TZCA的衍生物具有非常好的色谱性能，对气相色谱 - 电子轰击电离 - 质谱（GC - EI - MS）提供非常灵敏的响应。基于衍生化，建立了同时测定人尿液中TZCA和Me - TZCA的方法。合成了氘代Me - TZCA（Me - TZCA - d(4)）作为分析尿液样本的内标（IS）。TZCA和Me - TZCA在pH 9.5条件下用甲苯从尿液中衍生化并萃取，然后将干燥的萃取物用100微升乙酸乙酯溶解并注入GC/MS系统。在浓度为0.05 mg/l时，TZCA和Me - TZCA的回收率分别约为102%和103%。在1毫升人尿液中，TZCA和Me - TZCA的方法检测限（MDL）分别为1.0和0.5微克/升。在浓度分别为0.05和0.2 mg/l时，TZCA和Me - TZCA的变异系数均小于6%。为了评估吸入甲醛（FA）（空气中约3.1和38.1 ppm FA）过程中TZCA的形成情况，在开始治疗后的3天内采集大鼠尿液样本。对照组中测定的TZCA平均量为0.07 mg/l，在3.1 ppm治疗期间为0.18 mg/l。在38.1 ppm治疗期间，TZCA水平升高至约1.01 mg/l。计划研究尿中TZCA是否可作为FA暴露生物监测的指标。
