建立电感耦合等离子体质谱法测定居住区大气中铍、 镉、 砷、 铅等痕量元素的分析方法。 通过超声浸提同时分离气溶胶样品中多种元素, 对仪器工作参数进行优化, 选取72Ge, 115In和204Tl作为测定元素的校正内标, 有效克服了基体效应、 接口效应和仪器漂移对测定信号产生的影响。 测定元素标准曲线的相关系数均优于0.999 5, 铍、 镉、 砷、 铅各元素的测定方法检出限分别为0.022, 0.020, 0.018和0.130 μg·L-1, 方法定量限分别为0.102, 0.093, 0.083和0.602 ng·m-3。 通过测定标准参考物质GBW(E)080212考察方法的准确性, 测定值均在标准值范围内。 取采样滤膜分别加入低、 中、 高浓度标准溶液进行测定, 样品加标回收率为91.6%~109.7%, 相对标准偏差介于0.7%~4.8%。 该方法精密度好、 准确性好, 简便、 快速、 灵敏, 适用于居住区大气中痕量元素铍、 镉、 砷、 铅含量的测定。

In the present paper, the method for determining the trace elements Be, Cd, As and Pb in air of residential areas by inductively coupled plasma-mass spectrometry was established. Ultrasonic leaching procedures were applied to extract the trace elements from the filter membrane of the atmospheric particulates. The operating condition of the instrument was optimized. 72Ge, 115In and 204Tl were chosen as the internal elements and the effect of matrix, interface and fluctuation of instrument was overcome effectively. Satisfactory linearity of working curves of four elements was obtained, giving all the correlation coefficients over 0.999 5, and the detection limit of the method was between 0.006 and 0.045 ng·m-3. The mean values of National Standard Reference Material GBW(E)080212 were in agreement with the certified values. The sampling filters membranes, divided into four equal parts and with added standard solution with different concentions were analyzed, and the recovery rate of samples were in the range of 91.6%～109.7% with the related standard deviation between 0.7% and 4.8%. The obtained results showed that the method of determining the trace elements Be, Cd, As and Pb in air of residential areas by inductively coupled plasma-mass spectrometry proved to be simple, accurate, sophisticated and stable.