Abstract: The time-dependent drift is one of the main factors that control the data uncertainties in the analysis using inductively coupled plasma mass spectrometer. In this paper, a systematic study is carried out to explore the regularity and mechanism of the time-dependent drift effect of various elements. The results show that: (1) The degree of drift of various elements over time is significantly different; (2) The degree of drift is related to the mass of the studied element; (3) The distribution of different elements in the plasma are quite different, which may relate to the diffusion of elements in the plasma. In addition to the differences in the distribution patterns of the studied elements, the distribution patterns of elements in the plasma is unstable, and the combination of the two factors may lead to time-dependent drift. Finally, we found that the time-dependent drift is not affected by the concentration of elements. This research has important implication on understanding the time-dependent drift effect of inductively coupled plasma mass spectrometry and solutions to reduce the drift as well. 

Key words: ICP-MS, multielement analysis, the time-dependent drift