Lee Bee Lan, Ong Her Yam, Ong Yeong Bing, Ong Choon Nam
Department of Community, Occupational and Family Medicine, Faculty of Medicine, National University of Singapore, 16 Medical Drive, Singapore 117597, Singapore.
J Chromatogr B Analyt Technol Biomed Life Sci. 2005 Apr 25;818(2):277-83. doi: 10.1016/j.jchromb.2005.01.009.
Benzene is a human carcinogen and its metabolite, urinary trans,trans-muconic acid (ttMA), is a biomarker for risk assessment. However, most of the existing methods were not sensitive enough for monitoring of low level exposure. This paper describes a HPLC-UV method for ttMA determination with enhanced selectivity and sensitivity. A 30 mg OasisMAX cartridge was used to clean-up 50 microl of urine sample and gradient elution was performed on a Zorbax SB-C(18) column (30 degrees C). ttMA was detected at wavelength 263 nm using a UV diode array detector (DAD). The two mobile phases used were (A) 150 mM ortho-phosphoric acid containing of 9% (v/v) methanol; and (B) 125 mM ortho-phosphoric acid containing 30% (v/v) acetonitrile. The method was validated with 61 urine samples collected from non-occupationally benzene exposed individuals and 14 quality control specimens from an international quality assessment scheme. The urinary ttMA concentrations (mean+/-S.D.microg/g creatinine) were 90+/-34 for smokers (n=26), 49+/-39 for non-smokers (n=21) and 23+/-18 for non-smoking hospital staff (n=14). A correlation coefficient, r=0.99 was found with 14 external quality specimens for ttMA ranged from 0.4 to 6.8 mg/l. The recovery and reproducibility were generally over 90% and the detection limit was 5 microg/l.
苯是一种人类致癌物，其代谢产物尿反式，反式-粘康酸（ttMA）是风险评估的生物标志物。然而，现有的大多数方法对低水平暴露的监测不够灵敏。本文描述了一种用于测定ttMA的高效液相色谱-紫外检测法，该方法具有更高的选择性和灵敏度。使用30mg的OasisMAX柱对50微升尿液样品进行净化，并在Zorbax SB-C(18)柱（30℃）上进行梯度洗脱。使用紫外二极管阵列检测器（DAD）在263nm波长处检测ttMA。所用的两种流动相分别为：（A）含9%（v/v）甲醇的150mM正磷酸；（B）含30%（v/v）乙腈的125mM正磷酸。该方法用从非职业性接触苯的个体收集的61份尿液样品以及来自国际质量评估计划的14份质量控制样本进行了验证。吸烟者（n=26）的尿ttMA浓度（平均值±标准差，微克/克肌酐）为90±34，非吸烟者（n=21）为49±39，非吸烟医院工作人员（n=14）为23±18。对于14份ttMA浓度范围为0.4至6.8mg/l的外部质量控制样本，相关系数r=0.99。回收率和重现性一般超过90%，检测限为5微克/升。
