Study of the possibility of registering the anions F-, Cl-, Br- as silver halide using mass spectrometry with surface-assisted laser desorption/ionization

Abstract

The article is devoted to a mass spectrometric study of a possibility to detect the anions F^-, Cl^-, Br^- in aqueous solutions of both sodium and silver halides using matrix assisted laser desorption/ionization mass-spectrometry (MALDI). The mass spectra of sodium salts were demonstrated to contain a large number of peaks of unknown composition that do not allow their relation to the corresponding anions. At the same time, some peaks in the mass spectra of the corresponding silver salts, allow such a reference to be made in a number of cases. Sodium halides and silver nitrate were put on the target made from stainless steel, gold coated stainless steel and double-side scotch coated stainless steel. Concentration of sodium halides and silver nitrate were 10^-13-10^-11 g/mkl and 10^-8 g/mkl, respectively. The investigation of mass-spectra of respective blanks for studied targets has shown that minimal blank was registered for double-side scotch coated stainless steel target. Therefore most of experiments was carried out using this tagret. Using this target it was shown possibility of registration of surface assisted lazer desorbtion/ionization (SALDI) for 10^-13-10+ g of silver halides. Mass-spectra of these halides  (10^-13-10^-11 g/mkl) contained the same claster ions for defferent quantities. Besides that unidentified ions were registered, the number and m/z of which depended on quantizy of an analyte in the sample. For more reliable of analytes content in the sample using SALDI additional research is required