Removal of interferences in the speciation of chromium using an octopole reaction system in ion chromatography with inductively coupled plasma mass spectrometry

摘要

When inductively coupled plasma mass spectrometry (ICP-MS) is used for the detection of ~(52)Cr (83.8%) species in ion chromatography (IC), interference from polyatomic ions such as ~(40)Ar~(12)C~+and ~(35)C1~(16)O~1H~+, often occurs due to their mass at mlz 52.To address the issue, an octopole reaction system (ORS) in ICP-MS, including He and H2 modes, was used to determine whether the background and interference from polyatomic ions could be reduced in the detection of ~(52)Cr.Compared to standard mode, the polyatomic ions were reduced by either He or H_2;for example, more than 97 and 98% of ~(35)C1 was removed using a He and H2 tune, respectively.However, the detection sensitivity for ~(52)Cr was decreased, for example, the sensitivity was 27.95 and 67.02% of the standard mode for Cr(EDTA)_2-using a He and H_2 tune, respectively.The H_2 tune is recommended for the detection of ~(52)Cr at a flow rate of 2.0 mL/min with detection limits in the range of 0.2-0.4 mu g/L.The developed method was used to measure chromium speciation in waters containing high concentration of chloride.