Compounds In Water Samples Research Articles

Rapid sensitive speciation analysis of butyl- and phenyltin compounds in water by capillary gas chromatography atomic emission spectrometry (GC-AES) after in-situ ethylation and in-liner preconcentration

A rapid, simple and sensitive method has been developed for the simultaneous determination of butyl- and phenyltin species in environmental waters. The ionic organotin compounds are ethylated in the aqueous phase using sodium tetraethylborate (NaBEt4) and extracted with hexane. A 25 μl aliquot of the extract is injected at a low temperature into a Tenax filled liner. After solvent venting the analytes are transferred onto the capillary column using programmed temperature vaporization (PTV) injection. Detection is done by means of a microwave induced plasma atomic emission detector (MIP AED). The method allows the determination of butyl- and phenyltin compounds in water samples down to the level of 0.1 ng/l (as Sn) while 50 ml of sample is sufficient for analysis. The accuracy of the method was confirmed by GC-AAS after chelation and Grignard derivatization.

Sensitive speciation analysis of lead ion environmental waters by capillary gas chromatography microwave-induced plasma atomic emission spectrometry

Optimization of microwave-induced plasma atomic emission detection for the speciation of organolead compounds in water samples is described. The absolute detection limits achieved vary from 0.02 to 0.1 pg (as Pb) and are dependent on the volatility of the species determined. Two procedures for the separation and enrichment of organolead in water samples were evaluated. Ionic organolead species were extracted as their diethyldithiocarbamate complexes either with one portion of hexane at pH 8 or twice with pentane at pH 9, with preconcentration in the latter instance by rotary evaporation of the solvent. The detection limits obtained were down to 2 and 0.1 ng l −1, respectively for 100-ml samples. Propylation and butylation were compared for derivatization of organolead species in the extracts. Examples of results for rain and tap water analyses are given.

A new screening procedure for the estimation of oxidizable organic compounds in water samples

Immobilized lead dioxide (supported on SiO2) has been used as the packing material in a solid phase reactor for the oxidation of organic compounds in water samples by flow injection analysis (FIA). On-line oxidation takes place in a FIA-system; this allows the detection of mobilized Pb2+ either photometrically, after complex formation with 4-(2-pyridylazo)-recorcinol (PAR), or directly with flame-AAS. The oxidation yield is quite different (0–100%) for a variety of organic compounds; however, calibration was possible in all cases investigated. Thus the systems can be used for the screening of polluted waters and as a post-column chemical-reaction detector (e.g. after HPLC-separation of organic compounds). After modification the FIA determination of COD equivalent values should be possible.

Household Odors Associated With the Use of Chlorine Dioxide

In recent years, reports have indicated that the use of chlorine dioxide (ClO2) instead of chlorine as a preoxidant during water treatment is somehow related to the production of offensive odors at customers' homes and businesses. These odors were described by terms such as “kerosenelike,” “cat‐urine‐like,” and “strong chlorinous.” Attempts to isolate and identify the odor‐causing compounds in water samples taken from treatment plants and homes were unsuccessful. Suggestions from others that the offensive odors were in some way related to the presence of new carpeting in homes and businesses provided the basis for additional experiments. The principal conclusions derived from the study are that the strong chlorinous odors are caused by ClO2 itself, whereas the kerosenelike and cat‐urine‐like odors are products of gas‐phase reactions between ClO2 liberated from the water and organic substances in the air inside the customer's residence.

The Analysis of Tecnazene (2,3,5,6-Tetrachloronitro-benzene) and its Metabolites in Water and Fish

Abstract A method for the analysis of Tecnazene (2,3,5,6-tetrachloronitrobenzene) and its major metabolites (2,3,5,6-tetrachloroaniline and 2,3,5,6-tetrachlorothioanisole) is presented. This rapid analytical technique was developed to measure these compounds in samples of water and fish produced during the course of toxicological investigations. Water samples were extracted into hexane and analysed by high resolution capillary gas chromatography using flame ionisation detection (HRGC-FID). Fish samples were extracted into hexane, cleaned up on a short alumina micro-column and also analysed by HRGC-FID.

Screening methods for the identification of organic emissions from indoor air pollution sources

Development of on-line gas Chromatographic screening procedures is necessary to permit subsequent evaluation of materials in test chamber studies. This screening uses techniques such as static vapor-phase sampling by ‘headspace’ methods, and a dynamic method similar to the ‘purge-and-trap’ procedures used for determination of volatile organic compounds in water samples. These are methods of sampling that simulate the chamber conditions on a small scale, while allowing emissions to be collected and analyzed. The evaluation is done to select gas Chromatographic columns and develop operating conditions that will permit the rapid and reliable separation of chemical compounds generated during testing. The Chromatographic procedure is used in the qualitative identification of chemical compounds by gas chromatography/mass spectrometry. After identification of the compounds or, alternatively, their chemical classes, representative members are selected as calibration standards for the actual emission testing program. The standards selected are adequate to allow, in most cases, either quantitative or semi-quantitative calculation of the amount of each material present in the chamber exhaust gas. The use of response curves for the chemical classes allows subsequent recalculation of the amounts for each compound.

Determination of trace volatile organic compounds in water samples by membrane introduction mass spectrometry.

A new method of analysis was proposed based on the use of permselective membrane which gives the possibility of enriching and analyzing trace volatile organics in waters. A silicone membrane introduction device which is simple and easy to construct was designed to couple with JMS-D300 Mass Spectrometer. A quantitative formula which is available in the Membrane Introduction Mass Spectrometry was deduced. This paper studied the determination of alkanes, aromatic compounds and halogenated organics in waters by MIMS and discussed the effects of equilibrium time, temperature, sample volume, sample matrix etc. on responses of analyzed components. It was found that 22 volatile organics presented a wide linear concentration range from ppb to ppm, detection limits from 0.1 to 10 ppb and recoveries from 90% to 110%.

The Impact of Tributyl Tin (TBT) Antifouling Paints on Molluscan Fisheries

Laboratory and field experiments carried out during 1982–84 confirmed that some UK estuaries contained sufficient organotin compounds to cause reduced meat yields and shell thickening in the Pacific oyster, Crassostrea gigas. Historically the European flat oyster, Ostrea edulis, has been the basis of an important fishery on the east coast of England but the population has recently declined to an all-time low. Laboratory experiments have been carried out to compare larval survival, growth of spat and the development of gametes in adult O. edulis, and the growth of spat of four other bivalve species in the presence and absence of organotin toxins. The results from these experiments are discussed in relation to the concentrations of organotin compounds in samples of water and oyster tissues, from several sites in the UK, and the reproductive behaviour of adult oysters from natural stocks in the Crouch/Roach estuary system. The data strongly suggest that TBT is at least a contributory factor and probably a major cause of the failure in recent years of O. edulis to reproduce naturally in the Crouch Estuary. The UK Government has proposed legislation to control and reduce organotin emissions into the marine environment and this is briefly outlined.

Gas chromatographic determination of phenolic compounds in water, as their pentafluorobenzoyl derivatives

A sensitive gas chromatographic method for the determination of phenolic compounds in water samples has been developed. The phenols are converted by means of pentafluorobenzoyl chloride to the corresponding acyl derivatives. The procedure, specific for phenolic compounds, is compared with pentafluorobenzylation and was found to be faster and simpler. The method has been applied to industrial waste water.