电感耦合等离子体-质谱法测定工作场所空气中锂及其化合物

Determination of lithium and its compounds in workplace air by inductively coupled plasma-mass spectrometry

目的评估硝酸消解法、洗脱法2种前处理方法以及电感耦合等离子体-质谱法(ICP-MS)的无气体(No Gas)模式和氦碰撞(He)模式2种测定模式用于测定工作场所空气中锂及其化合物的适用性。方法采用微孔滤膜采集工作场所空气中锂及其化合物,分别采用硝酸消解法、洗脱法2种前处理方法处理后,采用ICP-MS法No Gas模式或He模式测定。结果ICP-MS法No Gas模式和He模式下,锂在质量浓度为0.00~500.00μg/L时线性关系良好,相关系数均为0.999;锂的检出限、定量下限在No Gas模式下分别为0.04和0.13μg/L,在He模式下分别为0.12和0.39μg/L。采用酸消解法进行前处理,锂的加标回收率为96.9%~104.9%,批内相对标准偏差(RSD)为3.3%~5.0%,批间RSD为2.9%~5.3%;采用洗脱法进行前处理,锂的加标回收率为97.6%~102.1%,批内RSD为3.3%~4.6%,批间RSD为3.4%~4.8%。样品在常温下可至少保存14 d。结论ICP-MS法可作为工作场所空气中锂及其化合物的检测新技术,在仅测定锂及其化合物时建议首选洗脱法和No Gas模式。

Objective To evaluate the suitability of two pretreatment methods, the nitric acid digestion method and the elution method, and two measurement modes of inductively coupled plasma-mass spectrometry(ICP-MS), the No gas mode and the helium collision(He) mode, for the determination of lithium and its compounds in the workplace air. Methods We collected lithium and its compounds in the air of the workplace using the microporous filter membrane, and two pretreatment methods, the nitric acid digestion and elution methods were used for processing, and measured with the No gas mode and the He mode of ICP-MS. Results The good linearity range of lithium concentration in No gas mode and He mode of ICP-MS method was 0.00-500.00 μg/L, and the correlation coefficient was 0.999. The detection limit and the lower limit of quantification of lithium were 0.04 and 0.13 μg/L respectively in the No gas mode. In He gas mode: they were 0.12 and 0.39 μg/L respectively. Using the nitric acid digestion method for pre-treatment, the recovery rate of lithium addition was 96.9%-104.9%;the within-run and the between-run relative standard deviations were 3.3%-5.0% and 2.9%-5.3% respectively. Using the elution method for pre-treatment, the recovery rate of lithium addition was 97.6%-102.1%;the within-run and the between-run relative standard deviation were 3.3%-4.6% and 3.4%-4.8%, respectively. The sample could be stored at room temperature for at least 14 days. Conclusion The ICP-MS method can be used as a new technology for detecting lithium and its compounds in the air of workplace. It is recommended that the elution method and the No gas mode be the first choice when measuring lithium and its compounds.