Simultaneous determination of noble metals (Rh, Pd, Ir, Pt, and Au) in environmental samples by nebulized film dielectric barrier discharge vapor generation coupled with inductively coupled plasma mass spectrometry

Abstract

A novel sensitive vapor generation sampling method, nebulized film dielectric barrier discharge (NFDBD) coupled with inductively coupled plasma mass spectrometry (ICP-MS), was developed in this work for simultaneous determination of noble metals (Rh, Pd, Ir, Pt, and Au). In the presence of formic acid, a 5–11 fold improvement in the sampling efficiency of Rh, Pd, Ir, Pt, and Au by NFDBD was achieved compared with conventional nebulization. Under the optimized conditions, the relative standard deviation (RSD) of Rh, Pd, Ir, Pt, and Au determined at 5 μg L⁻¹ was between 1.4% and 4.3%, and the detection limits (LODs) of Rh, Pd, Ir, Pt, and Au were between 0.1 ng L⁻¹ and 0.7 ng L⁻¹. This NFDBD sampling technique not only operates with no requirement of unstable reagents, easy coupling with flow injection, along with high tolerance for coexisting ions, but also achieves lower LODs than the Na(K)BH₄–acid vapor generation system and UV photochemical vapor generation system for noble metal determination. This work also extends the scope of elements that can be determined by DBD plasma vapor generation and provides a highly efficient analytical approach for the determination of Rh, Pd, Ir, Pt, and Au in environmental samples, especially in natural water.