电感耦合等离子体质谱法加L-半胱氨酸及金测定汞

Determination of mercury by ICP-MS with L-cysteine and gold

目的 建立电感耦合等离子体质谱法（ICP-MS）测定样品中汞的方法。方法 样品经微波消解处理,加入L-半胱氨酸（0.1%）和金（200μg/L）,使其形成金汞齐和较稳定的络合物,减少容器对其吸附作用及记忆效应,用电感耦合等离子体质谱仪进行测定。结果 通过对各类标准物质及样品的检测,线性方程为y=2.568×10-3x＋3.34×10-4,相关系数（r）为0.999 9。食品样品按0.5 g取样量计算方法的检出限为11μg/kg。以精密度考察方法重现性,相对标准偏差（RSD）均〈5.0%,加标回收考察方法准确性,加标回收率为97.5%~102.5%。方法的各指标结果均令人满意。结论 本方法操作简便快捷,线性范围宽,灵敏度高,准确可靠,很好的解决了汞的吸附问题和记忆效应,用无碰撞池的电感耦合等离子体质谱仪测汞,能得到满意的结果。

Objective To establish a method for the determination of mercury in samples by inductively coupled plasma mass spectrometry （ ICP - MS）. Methods The sample was processed by microwave digestion, adding L - eysteine （0.1% ） and gold （ 200 g/L）, the gold amalgamation and the formation of a stable complex were obtained to reduce the adsorption effect and mem- ory effect, which were measured by the inductively coupled plasma mass spectrometry （ ICP - MS）. Results This method is simple and rapid, accurate and reliable with wide linear range and high sensitivity, which can well solve the mercury adsorption and memory effect, and can get satisfactory results, with no collision cell inductively coupled plasma mass spectrometer used for measuring mercury. Conclusion Through the detection of different kinds of reference materials and samples, linear equation was y = 2. 568 × 10 -3x ＋ 3.34 ×10 -4, with correlation coefficient（r） of 0.999 9. Food samples were collected and counted by 0.5 g, the detection limit of the method was 11 μg/kg. The precision of study method was used to evaluate the reproducibility, with the relative standard deviation （RSD） 〈 5.0%, and the accuracy of this method was investigated with spiked recovery, with the recovery rate within 97.5% - 102.5%. And all the results of this method were satisfactory.