Interlaboratory trial on the analysis of alkylphenols, alkylphenol ethoxylates, and bisphenol A in water samples according to ISO/CD 18857-2.

ISO/CD 18857-2 (International Organization for Standardization, Geneva) describes a new international standard method for the determination of octylphenol, nonylphenol, their mono- and diethyoxylates, and bisphenol A in nonfiltered samples of drinking, ground, surface, and wastewater. The method is based on the extraction of the analytes from an acidified water sample by solid phase extraction, solvent elution, derivatization, and determination by gas chromatography with mass spectrometric detection. For validation of this method, 14 laboratories from 4 different countries in Europe and Canada participated in an interlaboratory trial to determine the performance characteristics of the method, which are intended for publication in the corresponding standard. The interlaboratory trial was evaluated according to ISO 5725-2 and included two duplicate nonfiltered water samples: surface water containing the target compounds in an analyte concentration range from 0.05 to 0.4 microg/L and wastewater containing the target compounds in a concentration ranged from 0.1 to 5 microg/L. The repeatability variation coefficients (within-laboratory precision) varied for all samples and compounds between 1.9 and 7.8%, showing a sufficiently high repeatability of the method. The reproducibility variation coefficients (between-laboratory precision) were found to vary within a satisfactory range of 10.0-29.5% for surface water and 10.8-22.5% for wastewater. The recoveries as a measure of accuracy varied from 98.0 to 144.1% for surface water and from 95.4 to 108.6% for wastewater. The determined concentrations of the samples compared well to the "true" values, thus showing very satisfactory accuracy of the method. In the chromatogram of the surface water sample, a high unresolved background made up of coextractable matrix compounds was apparent. It is conceivable that compounds from this background may be responsible for enhanced recoveries of 144.1% for 4-nonylphenol (mixture of isomers) and of 123.4% for 4-nonylphenol monoethoxylate (mixture of isomers) in the surface water samples. The isotope-marked standard compounds developed in this context proved to be reliable internal standards that allow a precise and accurate quantitation of all compounds specified in ISO/CD 18857-2. The results of the interlaboratory trial confirmed that the analytical method is robust and reliable and can be used as a standard method to analyze the target compounds in water samples.

[Distribution pattern of chemicals in surface waters as a reflexion of entry pattern--volatile halogenated hydrocarbons]. / Stoffmusterverteilungen in Oberflächengewässern als Reflexion von Eintragsmustern--Leichtflüchtige halogenierte Kohlenwasserstoffe.

The part gives some data about various light volatile halogenated hydrocarbons in surface waters of the industrialized city and its surroundings--the halogenated forms, chloroform and bromoform and the most used solvents trichloroethylene, tetrachloroethylene, tetrachloromethane and 1,1,2,2-tetrachloroethane. 80% of the concentrations of chloroform, tri- and tetrachloroethylene were in the range of less than 1 microgram l-1, 90% of bromoform, tetrachloromethane and 1,1,2,2-tetrachloroethane were found to amount less than 0.1 microgram l-1. With the help of the differential-diagnostic assessment method described in the first part we tried to evaluate the data for tetrachloromethane. The highest values were obtained for almost all sampling points in April--a possible cause may be the use of this solvent for cleaning and repairing procedures with sport boats (although tetrachloromethane has been prohibited for such uses for some years there may be some remainders which were used for these purposes).