高效液相色谱与液质联用测定尿中苯巯基尿酸的方法比较

目的]通过高效液相色谱（HPLC）与液质联用（LC/MS）检测尿中苯巯基尿酸（SPMA）的方法比对,评价HPLC方法的可行性。方法]尿样经50%硫酸酸化、氯仿：异丙醇（体积比为5：1）萃取,挥干残渣用甲醇溶解后经十八烷基硅烷（ODS）柱分离,分别采用紫外检测器和质谱检测器检测;对86名职业苯接触者尿样采用两种方法比对分析,以LC/MS分析数据评定HPLC测定结果的有效性。结果]HPLC方法和LC/MS方法对SPMA的检出限（LOD）分别为40μg/L和10μg/L,SPMA保留时间分别为31 min和7.8 min左右。86份尿样中有13份为假阳性,两方法检测结果的相关系数为0.915,但HPLC检测数据高估LC/MS数据8%-21%。结论]HPLC法可作为职业苯接触者生物监测的初步筛检方法,LC/MS可准确定量测定尿中SPMA浓度。

Determination of Urinary S-phenylmercapturic Acid by HPLC and LC/MS:A Comparison of the Two Methods

Objective] To compare the validity of HPLC and LC/MS analysis of urinary S-phenylmercapturic acid（SPMA）so as to assess the feasibility of HPLC method in measuring SPMA.Methods] The urine samples were acidified by 50% sulfuric acid and pretreated by liquid-liquid extraction using chloroform ： isopropyl alcohol（5 ： 1,v/v）.The residue dissolved with methanol was injected in ODS-3 column for SPMA separation,followed by ultraviolet detector and LC/ESI-NI/ MS analysis,respectively.Paired measurements were applied to the analysis of 86 urine samples from workers occupationally exposed to benzene.HPLC results were evaluated by comparison with the LC/MS analysis.Results] The limits of detection of HPLC and LC/MS were 40 μg/L and 5 μg/L,respectively.Retention time of SPMA peak appear at about 31 min and 7.8 min,respectively.13 of 86 samples in HPLC analysis were assigned as false-positives.HPLC results compared with LC/MS data showed to overestimate SPMA concentrations of about 8%-21% and a correlation coefficient of 0.915 was calculated between the two methods.Conclusion] HPLC analytical method is suitable for preliminary screening of urinary SPMA in routine biomonitoring for benzene-exposed workers,while LC/MS could be an more accurate quantitative determination method for measuring urinary SPMA concentration.