Determination of group parameters for organically bound chlorine, bromine and iodine in precipitation

The presence of organically bound halogens in precipitation was studied by first adsorbing organics on activated carbon and then analysing the chlorid e, bromide and iodide formed during combustion of the carbon. A standard in strument for the group parameter AOX (adsorbable organic halogens) was used for the combustion. The halides formed were trapped in an alkaline solutio n and analysed by capillary zone electrophoresis. The method described enab led determination of sub-ppb concentrations of the group parameters AOCl, A OBr and AOI (adsorbable organic chlorine, bromine and iodine, respectively) . Analysis of rain and snow collected at different sites in Europe showed t hat organochlorines were responsible for the major part of the AOX content in all samples collected. Organically bound bromine was found in sub-ppb co ncentrations in all of the samples, whereas organic iodine was detected in only two of the samples. (C) 1998 Elsevier Science Ltd. All rights reserved .