Direct Aqueous Injection Gas Chromatography Research Articles

Determination of volatile organohalogen compounds in human urine.

A variant of thin layer headspace (TLHS) analysis with autogenous generation of the liquid sorbent was applied for the determination of volatile organohalogen compounds in urine. The analytes were isolated from the matrix at an elevated temperature in a TLHS column. They were then transported by a stream of purified air to a second TLHS column kept at sub-ambient temperature. Water vapor contained in the air condensed in the second column together with the analytes. The effluent from the second column was analyzed by direct aqueous injection gas chromatography with electron capture detection (DAI-GC-ECD). It has been established that the complex urine matrix did not affect the results at a 95% confidence level. Volatile organohalogen compounds were detected in urine of employees of a chemical laboratory where halogenated solvents were used. The urine of people who were not exposed contained insignificant or undetectable levels of these compounds. Urine levels of target analytes were the higher, the longer a person was exposed to them. The results obtained confirm that the urinary system participates in excretion of volatile organohalogen compounds.

Direct aqueous injection gas chromatography on a potassium fluoride crystal hydrate-containing sorbent: Determination of volatile organic solvents in the fermentation broth of Clostridium strains

For the direct aqueous injection gas chromatographic determination of volatile organic solvents (acetone, ethanol, butanol) in culture spent media of Clostridium acetobutilicum, a sorbent which contains potassium fluoride crystal hydrate and a conventional stationary phase, Triton X-305, is used. Analysis is carried out using a stainless-steel column packed with the developed sorbent. The total time of analysis is less than 5 minutes at a column temperature of 65°. The column is stable for at least 1 year.

Determination of halocarbons in drinking water by direct aqueous injection gas chromatography

Determination of halocarbons in drinking water by direct aqueous injection gas chromatography

Development of Analytical Methodology and a Report on Collaborative Study on the Determination of Morpholine, Cyclohexylamine, and Diethylaminoethanol in Aqueous Samples by Direct Aqueous Injection Gas Chromatography

A direct aqueous injection gas chromatographic procedure for the determination of morpholine, cyclohexylamine, and diethylaminoethanol has been developed. The method employs graphitized carbon B (60 to 80 mesh) coated with 4.8% polyethylene glycol 20 M + 0.4% potassium hydroxide and a flame ionization detection system. The detection limits (3 × signal-to-noise ratio) for morpholine, cyclohexylamine, and diethylaminoethanol were 55 ng, 52 ng, and 53 ng, respectively. Five spiked samples containing the three amines in concentrations ranging from 0.5 to 3.0 mg/mL after appropriate dilution have been analyzed by six laboratories. A duplicate of one concentration level has been separately spiked with 50 ppm of iron salts to study the influence of iron salts on the analytical technique. Statistical treatment complementary to that outlined in ASTM D 2777-86 was applied. Significant biases were observed at some spike levels for morpholine and cyclohexylamine; bias changes were not consistent with increasing concentration. No significant biases were noted for diethylaminoethanol. There was no evidence of interlaboratory variations for any concentrations of morpholine. Significant interlaboratory variability was observed for some concentrations of cyclohexylamine and diethylaminoethanol. Further, the presence of iron salts shows negligible influence on the analytical technique for the three amines.

Direct aqueous injection gas chromatography with a flame‐ionization detector: Effect of column temperature and sample volume

Direct aqueous injection gas chromatography with a flame‐ionization detector: Effect of column temperature and sample volume

Industrial applications of chromatography : I. Determination of methanol, n-butanol and toluene by direct aqueous injection gas chromatography

Dosage du methanol, du butanol et du toluene dans des eaux usees. Etude de l'effet de l'eau sur les temps de retention des composes et sur la detection

Trace analysis of volatile polar organics by direct aqueous injection gas chromatography

Procedures for the quantitative analysis of industrial effluents which involve concentration by solvent extraction or the purge-and-trap method are time-consuming, labor-intensive, and prone to error. Direct aqueous injection gas chromatography using an electron-capture detector for the analysis of volatile halocarbons at the ppb level is in routine use in many laboratories. We now discuss the development of a similar protocol for the analysis of volatile polar organics such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and tretrahydrofuran using a flame-ionization detector.

Quantitative analysis of 68 polar compounds from ten chemical classes by direct aqueous injection gas chromatography

Porous polymer packings have been used successfully in many applications of direct aqueous injection gas chromatography. We have expanded the use of aqueous injection to the quantitative analysis of 68 alcohols, acetates, ketones, ethers, sulfides, aldehydes, diols, diones, nitriles and amides on a glass column packed with unmodified tenax GC using a flame-ionization detector. Analysis of single- and multicomponent mixtures, accurate standard preparation, assessment of analytical errors, limitations of the method and problems encountered are discussed. Peak ghosting and tailing were not serious problems. The analytical error between chemical classes expressed as the coefficient of variation between duplicate samples ranged from 0.81 % for nitriles ( n  3) to 7.09 % for ethers ( n  5). The method described is fast, precise and accurate, requires little sample preparation and is applicable to a wide variety of compounds.

Reaction processes effecting the analysis of chloroform by direct aqueous injection gas chromatography

Several important reaction processes which influence the analysis of chloroform by direct aqueous injection (DAI) gas chromatography have been identified through an investigation of the chlorination reactions of humic acid and a series of simple polyhydroxyaromatic and diketone model compounds in dilute solution. The reaction of chlorine with each substrate system was studied over the pH range 2–12. Gas chromatographic analysis by the DAI and organic solvent liquid-liquid extraction (LLE) procedures gave different measurements for the yield of CHCl 3 depending on the pH of the reaction solution and the chemical structure of the substrate. Under acidic and neutral conditions, a variety of trichloromethyl-substituted intermediates were identified at high concentrations in addition to chloroform by GC/MS. Chloral hydrate, trichloroacetic acid, pentachloroacetone and hexachloroacetone undergo hydrolysis and/or decarboxylation to form CHCl 3 at the high injection port temperatures employed in aqueous injection GC analysis. The results obtained in the current study indicate that the decomposition of these and structurally-related species accounts for differences previously observed upon application of the DAI and either the LLE or purge-and-trap techniques for the determination of CHCl 3 in chlorinated natural waters.

Direct aqueous injection gas chromatography for the analysis of trace organics in water

A novel and simple method of direct aqueous injection gas chromatography is described, whereby water is selectively removed by diffusion across a permaselective membrane prior to the sample entering the chromatographic column. The technique is demonstrated using electron-capture gas chromatography to determine trace halocarbons in drinking water samples using direct injection of 1–20-μl aliquots.

Quantification of water-soluble gasoline fractions using a radioisotopic standard with direct aqueous injection-gas chromatography.

A new gas liquid chromatography (GLC) technique was devised to determine the amounts of individual water-soluble gasoline fractions (WSGFs) present in aqueous solutions. The technique described permits direct aqueous injection of water samples without the problems associated with solvent extraction techniques (JELTES and VELDINK 1967, LYSYJ and RUSSELL 1974, MALLEVIALLE 1974), and provides more accurate quantification.

Analysis of volatile, halogenated organics in water by direct aqueous injection-gas chromatography.

Analysis of volatile, halogenated organics in water by direct aqueous injection-gas chromatography.

Quantitative determination of traces of indole and o-phenylphenol by direct aqueous-injection gas chromatography.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTQuantitative determination of traces of indole and o-phenylphenol by direct aqueous-injection gas chromatographyT. S. Hermann and A. A. PostCite this: Anal. Chem. 1968, 40, 10, 1573–1576Publication Date (Print):August 1, 1968Publication History Published online1 May 2002Published inissue 1 August 1968https://doi.org/10.1021/ac60266a002RIGHTS & PERMISSIONSArticle Views42Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (457 KB) Get e-Alerts Get e-Alerts

Phenolic Analyses by Direct Aqueous Injection Gas Chromatography

This article summarizes the preliminary results of a continuing investigation to develop gas‐liquid chromatographic procedures using direct injection of aqueous samples for analysis of phenolic‐type materials in water. This study demonstrated the ability of these procedures to separate and identify structurally related materials, determined the method's precision and accuracy, and compared its advantages and limitations with the commonly employed 4‐aminoantipyrine colorimetric method.