Potential direct mass spectral elemental analysis of solids by microwave plasma torch surface release and ionization

Abstract

Direct and rapid analysis of various elements from solid surfaces under ambient conditions remains a great challenge. In this work, in situ release and ionization of volatile vapor generation elements including As, Sb, Se, Ag, Te, Pb, Cu and Bi from solids by direct microwave plasma torch-mass spectrometry (MPT-MS) were studied. The results showed that MPT could induce in situ surface release and ionization of various volatile species forming elements directly from solid samples under ambient conditions without any reagent consumption and sample pretreatment. The method features high throughput and high selectivity, with the overall online data acquisition time for a single solid sample being within 5 seconds. Quantification analysis of As and Sb was also performed in soil samples with GBW07405 as the standard. The obtained detection limit was 1.4 μg g⁻¹ for As and 0.35 μg g⁻¹ for Sb. The high throughput, high sensitivity and simplified manipulation of MPT-MS was expected to provide a useful tool for the direct analysis of solid samples in the field of geochemistry, food safety, and environmental protection.