高基质进样-电感耦合等离子体质谱法测定职业接触人员血中铊

职业接触人员血中铊浓度可反映其体内暴露的信息。因此，建立血中铊浓度的检测方法具有非常重要的意义。目前，国内血中铊检测没有国家标准方法，国内外文献报道的方法均存在一定缺点。为了获得准确的职业接触人员血中铊浓度，建立了高基质进样（HMI）-电感耦合等离子体质谱（ICP-MS）测定职业接触人员血中铊含量的方法。通过对等离子体模式和前处理方法进行了选择，0.20 mL血样用0.1% Triton X-100+0.5%硝酸混合溶液处理后，采用在线加入内标的方式对铊含量进行了检测。在最佳的分析条件下，205Tl在0.02～4.00 μg·L-1范围内线性关系良好，Y=0.010 33X+0.000 12，相关系数（R）为0.999 9。最低检出限（detection limit，DL）为0.005 μg·L-1，最低定量限（quantification limit，QL）为0.02 μg·L-1；当取样量为0.20 mL，定容体积为5.00 mL时（血样25倍稀释），方法检出限（MDL）为0.12 μg·L-1，方法定量下限（MQL）为0.42 μg·L-1，测定范围为0.42～100 μg·L-1。在全血样品中添加水平为2.50，15.0和75.0 μg·L-1时的平均回收率为92.7%～103.8%。每个样品重复测定7次，批内精密度（RSDs of in-batch）为1.71%～2.81%，批间精密度（RSDs of interbatch）为2.84%～4.77%，表明，该方法的准确度及精密度良好。连续监测50个样品（包括标准溶液、质量控制样品和全血样品），内标元素209Bi的信号变化为+7.7%，表明方法稳定性较好。将建立的新方法用于30份职业接触人员全血的分析检测，其中4份血样的铊含量大于方法检出限，但低于方法定量下限，其余26份血样均低于方法检出限，且30份全血样品中铊含量均在平均背景范围内。结果表明30位职业接触人员铊内暴露水平很低，其工作场所铊对人体基本无潜在的健康影响。该方法简单快速、准确度高、稳定性好，适用于实际样品的大批量检测。

Determination of Thallium in Blood of Occupational Exposed Population by Inductively Coupled Plasma Mass Spectrometry With High Matrix Introduction

Tallium in the blood of occupationally exposed population may reflect their exposure in vivo. Therefore, it is very important to establish a method to determine thallium in blood. At present, there is no national standard method for the determination of thallium in blood in China, and the methods reported in domestic and foreign literature have some shortcomings. In order to obtain accurate thallium concentration in the blood of occupationally exposed population, a new method was developed for thallium in blood by inductively coupled plasma mass spectrometry with high matrix injection. In this study, plasma mode and pretreatment method were selected. After the 0.20 mL sample was pretreated with the mixed solution of 0.1% Triton X-100 and 0.5% nitric acid, the thallium content was detected by adding internal standard online. Under the optimal conditions, good linearity was obtained in the concentration range of 0.02～4.00 μg·L-1 with a linear calibration curve of Y=0.010 33X+0.000 12 (R=0.999 9). The detection limit (DL) and the quantitative limit (QL) were 0.005 and 0.02 μg·L-1. When the sample volume and constant volumes were 0.20 and 5.00 mL respectively, the method detection limit (MDL) and the method quantitative limit (MQL) were 0.12 and 0.42 μg·L-1, and the analytical range of this method was 0.42~100 μg·L-1. The average recoveries at three fortified levels (2.50，15.0 and 75.0 μg·L-1) were 92.7%~103.8%. The relative standard deviations of in-batch (RSDs of in-batch) ranged from 1.71% to 2.81%, and the relative standard deviations of interbatch ranged from 2.84% to 4.77%, which indicated the accuracy precision of the method were good. The signal variation of 209Bi internal standard isotope in 50 samples(including standard solution, quality control samples and whole blood samples) was less than 7.7%, which showed that the method had good stability. The established method was successfully applied to the analysis of 30 whole blood samples in the occupational exposed population. Four samples were above the MDL, but below the MQL. The other 26 samples were below the MDL and all the 30 samples were within the average background range. This method was simple, rapid, accurate and stable and suitable for analysing of large quantities of actual samples. The results showed that the exposure level of thallium was shallow in vivo, and there was no potential health risk of thallium to 30 professional contacts in their workplace.