ANALYSIS OF POLYCHLORODIBENZO-PARA-DIOXINS IN RAW AND TREATED WATERS .1. EVALUATION OF GRAB SAMPLE METHODOLOGY FOR PART-PER-QUADRILLION ANALYSIS

A liquid-liquid extraction and isolation procedure for the concentration of chlorinated dioxins from 12 L samples of treated and raw water was evaluated. It was demonstrated that water samples could be stored for one week prior to extraction without significant loss of dioxins. Extraction and isolation procedures were evaluated at pg/L levels by the use of 13C labelled dioxin standards to determine recoveries. PCDD recoveries were quantitative (65-120%) except for octachlorodioxin where lower recoveries (40-60%) were due to losses in both the Florisil and carbopack column isolation steps. It is recommended that the concentration of each dioxin congener in water samples be calculated relative to the percent recovery of its specific l3C congener. © 1990, Taylor & Francis Group, LLC. All rights reserved.