ToF-SIMS as an alternative tool for the qualitative and quantitative analysis of polar herbicides

Abstract

In this paper, time-of-flight secondary ion mass spectrometry (ToF-SIMS) is evaluated as a direct method for quantitative analysis of glyphosate (GLY) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). In contrast to other pesticides, glyphosate and 2,4,5-T are highly polar and water-soluble; therefore they are not easily detected with classical procedures. Quantifications of the two pesticides based on ToF-SIMS spectra from standard solutions deposited on gold and aluminium are researched. Only negative secondary ion fingerprints of the two pesticides should be used for quantification. Limits of detection and limits of quantification of both pesticides largely depend on chemical background and contamination level. Special attention was given to molecular mass peak fingerprints and main fragments evolution in order to detect a potential cross contamination or mass peak interferences.