Determination of adsorbable organic halogens (AOX) and their molecular weight distribution in surface water samples
1988; Elsevier BV; Volume: 17; Issue: 10 Linguagem: Inglês
10.1016/0045-6535(88)90010-0
ISSN1879-1298
AutoresBo Wigilius, Bert Allard, Hans Borén, Anders Grimvall,
Tópico(s)Analytical chemistry methods development
ResumoThe hypothesis that complexing of chloride ions with humic substances may interfere with the analysis of adsorbable organic halogens (AOX) in surface waters was tested and rejected in experiments with the radioactive isotope 36Cl. However, the recovery of AOX from activated carbon added to water samples was strongly pH-dependent and thereby statistically correlated to the recovery of humic substances. A procedure for determining the molecular weight distribution of AOX in surface water samples was developed. After preconcentration in a rotary evaporator, the sample was fractionated with a Sephadex G-25 column, and AOX were determined for each of the fractions collected. A HPLC (HPSEC) column, giving the same elution order as the Sephadex column, provided a method for calibration of the fractionation. Analysis of surface waters not affected by industrial effluents showed that such waters normally contained 10–50 μg/l of AOX, and that the molecular weight distribution of the AOX did not differ markedly from that of the aqueous organic substances in general. The observed concentrations of AOX indicate that there is a large, thus far unidentified, source of organohalogen compounds in surface water.
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