Determination of trihalomethanes in soil matrices by simplified quick,easy, cheap,effective, rugged and safe extraction and fast gas chromatography with electron capture detection

A method based on QuEChERS extraction is proposed for the determination of trihalomethanes (chloroform, bromodichloromethane, dibromocloromethane and bromoform) in soil samples. The new version of QuEChERS adapted to soil samples consists of liquid extraction with ethyl acetate, the addition of water to moisten the samples, salting-out partitioning of the water with anhydrous MgSO₄, and direct injection of the organic extract, obtained after the centrifugation step, into the gas chromatograph. This simplified extraction procedure maintains the advantages of the original method and avoids some steps, making the final procedure simpler, faster, and cheaper, with the consequent reduction in errors associated with sample manipulation. The experimental conditions of the analytical method, based on fast gas chromatography (FGC) and micro-electron capture detection (μECD), were optimized. The column and oven program used allowed fast separation of the compounds in less than 4 min and the total analysis cycle time was as short as 10 min. The existence of a matrix effect was checked and the analytical conditions of the method were studied in a fortified garden soil sample. The highly sensitive and selective detector used afforded to detection limits in the order of ng/kg for the target compounds. To validate the proposed method two certified reference materials (CRMs) were analyzed.     

Derivatization and determination of arsenic in marine samples by gas chromatography with electron capture detection

Summary Arsenic in marine samples was determined by gas chromatography with electron capture detection after derivatization with 2,3-dimercaptopropanol. Biological tissues and sediments were analyzed after acid decomposition. For sea water, arsenic was preconcentrated by coprecipitation with hydrous iron (III) oxide. The results obtained by this approach compare favourably with the certified values of the reference materials analyzed. Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984     

Application of capillary gas chromatography with electron capture detection and split-splitless injection to the evaluation of volatile halogenated hydrocarbon removal using hydrogen peroxide after break-point chlorination in drinking water treatment

In this paper we report a way to evaluate the removal of volatile halogenated hydrocarbons formed after break-point chlorination in the Arno river raw water at the Mantignano Utility, Florence, Italy, following dechlorination by hydrogen peroxide. The removal evaluation is performed by GC-ECD on fused silica capillary columns with split-splitless injection on n-pentane extracts and by other analytical techniques such as UV₂₅₄ absorption, TOC and TOX. Both laboratory and pilot plant data on Arno river raw water are reported and discussed.     

Determination of nitrated polycyclic hydrocarbons in aerosols using capillary gas chromatography combined with different electron capture detection methods

A method is described which allows the determination of subnanogram concentrations of mono- and dinitrated polyaromatic hydrocarbons with two to four ring systems in aerosol samples. High performance liquid chromatography is used to separate the nitro compounds from other classes of substances. Carbozoles elute in the same fraction. Both electron capture detection and negative ion chemical ionization mass spectrometry combined with capillary gas chromatography are used for quantification. Use of these two methods leads to a considerable improvement of selectivity and sensitivity for nitrated compounds. In contrast to the situation with a nitrogen-sensitive detector, carbazoles do not interfere and detection limits in the order of 10–200 pg/m³ are possible. The applicability of the method is critically discussed. Determination of nitrated polyaromatic hydrocarbons in aerosol samples from an aluminum smelter serves as an example.     

Determination of carboxylic acids and phenols in water by extractive alkylation using pentafluorobenzylation,glass capillary GC and electron capture detection

A method is presented for the simultaneous determination of a wide range of carboxylic acids and phenols in water. Extractive alkylation is used with the tetrabutylammonium ion as counter ion and pentafluorobenzylbromide as alkylating agent. Extracts are analyzed by glass capillary gas chromatography and electron capture detection. Using one ml of water sample, the detection limit lies in the range of 1–10 μg/l. Application has been made to the analysis of steam condensate and domestic sewage effluent.