电感耦合等离子体质谱仪长期稳定性的测定

Measurement of long-term stability of inductively coupled plasma mass spectrometer

使用微合金钢及高温合金两种不同基体的有证标准物质,利用检测标准GB/T32548—2016中的重复性和实验室内再现性精密度数据及χ^2统计量,对电感耦合等离子体质谱仪(ICP-MS)测量Sn、Sb、Pb和Bi的长期稳定性进行了测定。测定结果表明,电感耦合等离子体质谱仪在测量不同基体样品中不同元素时,长期稳定性不完全相同。在本实验条件下,Sn、Sb和Bi在连续11.5h的测量时间内,Pb在连续6.0h的测量时间内,各时段内精密度、正确度,时段内重复性,时段间总精密度,总平均值正确度均满足检测标准和统计要求,由此确定了本实验条件下电感耦合等离子体质谱仪的长期稳定性时间上限为6.0h。当不测量Pb元素时,电感耦合等离子体质谱仪的长期稳定性时间上限可延长至11.5h。在长期稳定性时间上限时间内,仪器无需再次进行校准曲线的测量和校正,节约了测量时间和成本。

The long-term stability of inductively coupled plasma mass spectrometer (ICP-MS) for the determination of Sn, Sb, Pb and Bi was measured by the repeatability and reproducibility precision within laboratory as well as χ^2 statistic according to standard GB/T 32548-2016. The certified reference materials of microalloyed steel and high temperature alloy with two matrixes were used for tests. The results showed that the long-term stability of ICP-MS was not the same during the determination of various elements in different matrix samples. Under experimental conditions, the statistical parameters such as precision, trueness and repeatability within periods, overall precision among periods and the trueness of general mean could meet the detection standards and statistical requirements for 11.5 h continuous measurement of Sn, Sb and Bi and 6.0 h continuous measurement of Pb. Therefore, the upper limit of long-term stability of ICP-MS under experimental conditions was 6.0 h for Pb. When Pb was not measured, the upper limit could be extended to 11.5 h. Within the upper limit of long-term stability, the measurement and correction of calibration curve was not necessary for the instrument, which saved time and cost.