Removal of Sulfur in Environmental Samples Prior to Gas Chromatographic Analysis for Pesticide Residues

Abstract

Extracts of soil, water, and sediment often contain large amounts of elemental sulfur. This sulfur causes considerable interference in the GLC analysis of early eluting compounds by electron capture or flame photometric detection systems. A method is described whereby sulfur is removed by refluxing with a copper-aluminum alloy. Using a sample volume of 1 ml, up to 50 ppm elemental sulfur can be removed. Recovery of chlorinated pesticides from desulfurized extracts is >80%. Parathion and malathion gave recoveries of approximately 50%.

Associations of chlorinated hydrocarbons with fine particles and humic substances in nearshore surficial sediments

“…Analysis of Chlorinated Hydrocarbons. The extraction, separation, identification, and quantification of chlorinated hydrocarbons were generally performed in accordance with the published literature (12)(13)(14)(15)(16)(17)(18). Details of the operation are described as follows.…”

Removal of sulfur interfering in the analysis of organochlorines by GC-ECD

“…Treatment with pyrogenic copper powder, 3,4 metallic mercury 5,6 or silver on silica gel, 7 and conversion with tetrabutylammonium (TBA) sulfite to thiosulfate 8 or with polymeric triphenylphosphine (TPP) to the corresponding sulfide, 9 are recommended for the removal of elemental sulfur in extracts. However, commercial polymeric TPP must be purified by longterm extraction with two extractants before use, 9 while the preparation of pyrogenic copper powder (Raney-copper) and silver-loaded silica gel is also laborious.…”