Identification of Impurities in High-Pure Arsine by Chromatography–Mass-Spectrometry

A method of chromatography–mass spectrometry is used to study the impurity composition of arsine synthesized by the reaction of arsenic chloride with sodium borohydride. Capillary adsorption columns with adsorbents modified silica and polytrimethylsilylpropine is used for the separation of impurities. Impurities are identified by comparing their mass spectra with the NIST database, published data, as well as by reconstructing their structures from fragment ions. Impurities of permanent gases; saturated and unsaturated hydrocarbons C 1 –C 6 ; chlorinated, oxygenated, and aromatic hydrocarbons; volatile inorganic hydrides; and alkyl derivatives of arsine, trimethyl fluorosilane, carbon sulfur dioxide, and dimethyl sulfide are identified in arsine. Mass spectra of C 2 H 3 AsH 2 , CH 3 AsHC 2 H 5 , and C 2 H 5 As 2 H 3 impurities are obtained for the first time.