S. G. Chu

Organic contamination in the greenhouse soils from Beijing suburbs, China.

Selected persistent organic pollutants including HCHs, DDTs and PAHs together with PAEs were determined in the greenhouse soils from Beijing suburbs. The total concentrations were 11.64-29.80 ng g(-1) for HCHs, 18.04-101.33 ng g(-1) for DDTs, 1.34-3.15 microg g(-1) for PAEs and 1.92-7.84 microg g(-1) for PAHs, respectively. Predominance of beta-HCH in all samples was obviously observed, suggesting a lack of new HCHs sources. High concentrations of DDE and DDD in comparison to their parents in the samples indicated that most of the DDT had been transformed into its metabolites. The contamination of PAHs was relatively serious and the most abundant compounds were 4-, 5- and 6-ring unsubstituted PAHs. The profiles reflect the important effect of traffic on the PAHs remaining in greenhouse soils. Three phthalate esters (DIBP, DnBP and DEHP) accounted for more than 97% of the phthalates studied. Analysis of n-alkanes was also performed in order to trace the natural or anthropogenic sources of hydrocarbons. Characterization and identification of these compounds in greenhouse soil may help in development of strategies to be used in monitoring organic pollutants in this region.

The determination of chlorophenols in waste water by capillary zone electrophoresis with an organic modifier

SummaryAcapillary zone electrophoretic method has been optimized to improve selectivity and resolution in the analysis of chlorophenols in waste water. Use of a buffer system containing organic solvent dramatically improved the separation of chlorophenols. It was shown that selectivity was strongly affected by electrolyte pH and the presence of organic modifiers. The results show that the determination of all seventeen chlorinated derivatives of phenol in water can be achieved by use of a single organic modifier. For example, with acetone as organic modifier all 17 chlorophenols could be separated and determined within 20 min. The standard deviation of migration times and peak areas of the chlorophenols were in the ranges 0.48–0.67% and 3.9–5.1% respectively. Detection linear ranges covered two orders of magnitude of concentration with correlation coefficients of 0.998–1.000, except for 4-chlorophenol. Quantitative aspects of capillary zone electrophoresis are also discussed. It was concluded that capillary zone electrophoresis is a potential method for determination of chlorophenol pollutants in waste water.