Preliminary results on the use of Tenax for the extraction of pesticides and polynuclear aromatic hydrocarbons from surface and drinking waters for analytical purposes

Fifty years of solid-phase extraction in water analysis--historical development and overview

The use of an appropriate sample handling technique is a must in an analysis of organic micropollutants in water. The efforts to use a solid phase for the recovery of analytes from a water matrix prior to their detection have a long history. Since the first experimental trials using activated carbon filters that were performed 50 years ago, solid-phase extraction (SPE) has become an established sample preparation technique. The initial experimental applications of SPE resulted in widespread use of this technique in current water analysis and also to adoption of SPE into standardized analytical methods. During the decades of its evolution, chromatographers became aware of the advantages of SPE and, despite many innovations that appeared in the last decade, new SPE developments are still expected in the future. A brief overview of 50 years of the history of the use of SPE in organic trace analysis of water is given in presented paper.

Tenax-GC Extraction Technique for Residual Polychlorinated Biphenyl and Polyaromatic Hydrocarbon Analysis in Biodegradation Assays

A rapid Tenax-GC extraction technique has been evaluated for use in conjunction with aqueous biodegradation assays for polyaromatic hydrocarbons and polychlorinated biphenyls. The method was quantitatively efficient and reproducible for phenanthrene, but variable and not quantitative for Aroclor 1254 (polychlorinated biphenyls). Aqueous sample volumes and varying concentrations of organic matter influenced polychlorinated biphenyl and polyaromatic hydrocarbon extraction efficiency. Phenanthrene recovery was decreased by soil extract but unaffected by spent bacteriological culture medium. Both types of organic matter caused significant reduction of Aroclor 1254 recovery. Polyaromatic hydrocarbon and polychlorinated biphenyl biodegradation assays, performed with reservoir samples, supported the laboratory evaluation. The study demonstrated the utility of the Tenax-GC extraction technique for phenanthrene analysis in biodegradation assessment; however, Tenax-GC extraction was not appropriate for Aroclor 1254 biodegradation studies.

Concentration of headspace, airborne and aqueous volatiles on Chromosorb 105 for examination by gas chromatography and gas chromatography-mass spectrometry

Techniques are described for the collection of volatile material from headspace vapours and the atmosphere and for the direct extraction of volatiles from aqueous solution by traps containing the porous polymer Chromosorb 105. The traps are inserted through a valve into a gas chromatograph which facilitates the desorption and transfer of the volatiles to high-resolution capillary columns. Selected applications of the technique are described.

The use of tenax for the extraction of pesticides and polychlorinated biphenyls from water. II. Tests with artificially polluted and natural waters

The application of Tenax to the extraction of organic micro-pollutants such as pesticides and polychlorobiphenyls from waters has been studied, and it has been observed that also in the presence of other pollutants (oil, surface-active substances, etc.) the results obtained with an absorption column of Tenax-Celite are equivalent to those obtained with the continuous liquid-liquid extraction technique. For natural waters that contain solids in suspension that adsorb pesticides, it may be necessary to filter the water before extraction with Tenax and then to extract the suspended solids separately. Analyses of river and estuarine sea waters, filtered before extraction, showed the effectiveness of Tenax, and the extracts obtained for the pesticides analysis prove to be much less contaminated by interfering substances than the corresponding extracts obtained by the liquid-liquid technique.

Organic micropollutants in air and water. Sampling, gas chromatographic-mass spectrometric analysis and computer identification

Organic micropollutants are sampled by dynamic enrichment on a porous polymer column and subsequently thermally eluted in a flow of helium. The eluted compounds enter gas chromatograph inlet and then pass into two parallel glass capillary columns with different stationary phases, in which they are separated. The separated compounds are detected by gas chromatographic (GC) detectors and by a mass spectrometer that is connected to one or other of the two capillary columns by "heart cutting" systems. The GC and mass spectrometric (MS) signals are fed via interfaces into a minicomputer which controls the MS scan and performs data acquisition, reduction and treatment on-line and off-line. The resulting GC and MS data are displayed on a line printer or a visual display unit. The minicomputer is connected by a telephone line to an IBM 370/165 computer, where a library search system has been implemented. Some difficulties encountered, data on the sampling recovery of model compounds and the identification of compounds in air and water samples by GC-MS data and library searches are discussed.

Trace analysis of organic volatiles in water by gas chromatography-mass spectrometry with glass capillary columns

Traces of volatile organic materials in water have been concentrated by gas phase stripping and adsorption onto a porous polymer. A simple all-glass sampling device is proposed which allows efficient concentration at elevated temperatures. Sample transfer from absorbent into a gas chromatographic column is effected by a simple one-step procedure involving heat desorption. The capacity of the absorbent has been determined for a number of model substances which are found in water. Under the sampling conditions used, compounds being less volatile than benzene are usually quantitatively retained, with some exceptions. Separations were effected with highly efficient glass capillary columns. Water samples, collected from a small number of locations, included both tap water and untreated waters. A number of volatiles have been determined by gas chromatography-mass spectrometry in drinking water and in a river which flows through an industrialized area. The drinking water examined contains a large number of chlorinated and brominated compounds whereas the river water is largely free from this class of substances. Derivatives of camphor and terpenes have been identified in this particular river.