SOLID PHASE EXTRACTION FOR DETERMINING ORGANIC COMPOUNDS IN HIGH IONIC STRENGTH SOLUTIONS

ABSTRACT

Extraction techniques for semi-volatile organic compounds from caustic and high ionic strength solutions are presented. It is demonstrated that simple liquid-liquid extraction from a high ionic strength aqueous solution can allow inorganic ions to partition from the aqueous phase into the organic extraction phase. The ability of solid-phase extraction (SPE) adsorbents to separate organic target compounds from a sample, without significant carry-over of inorganic material, is compared to that of Liquid-liquid extraction. The most useful SPE media was a commercially available alumina substrate coated with a robust non-polar phase. Extractions of three compound classes, are presented: aromatic, alkyl hydrocarbons and alkyl phosphates. Extraction yields ranged from 42 to 97.6% (6-12% RSD). The range of yields for each chemical class was 7.5-79.9%, 14.3-68.3% and 91.1-97.6% for the aromatic, alkyl hydrocarbons and alkyl phosphate compounds respectively.