Gas Chromatography-atomic Emission Detection Research Articles

Continuous liquid‐liquid extraction combined on‐line with capillary gas chromatography‐atomic emission detection for environmental analysis

AbstractThe on‐line coupling of a liquid‐liquid extraction system with capillary gas chromatography using atomic emission detection (GC‐AED) has been studied. The required large volumes of about 100 μl of an iso‐octane solution can be introduced into the GC‐AED system by using the AED solvent vent and a solvent vapor exit in front of the capillary analytical column. Test solutions containing several pesticides were detected using the carbon, chlorine, nitrogen and sulfur channels. Analyte detectability (in concentration units) was improved significantly and low concentractions of the test compounds could be determined (1–5 ng/ml). Aqueous samples were on‐line extracted and analyzed. The precision of the large‐volume injection itself as well as the total extraction‐GC‐AED system was satisfactory (RSD of ca. 2 and 4%, respectively). As a real‐life application, several ground water samples were screened.

Gas chromatography‐atomic emission detection (GC‐AED) set‐up for bio‐monitoring of PCBs and methylsulfonyl‐PCBs

AbstractGas chromatography‐atomic emission detection (GC‐AED) has been evaluated in order to determine the optimal conditions for chlorine and sulfur response of chlorinated biphenyls (CBs) and methylsulfonyl metabolites of CBs (MeSO2‐CBs). The influence of the shape of the capillary column end facing the plasma, make‐up gas flow, additional transfer line make‐up gas flow and reagent gas flows on the detector response has been studied. Using an additional make‐up gas flow applied through a transfer line capillary having a decreased outlet diameter yielded an increased detector response with minimum detectable levels for sulfur and chlorine of 1.7 and 20 pg, respectively. Further, a substantial decrease in peak tailing was achieved. The applicability of the method for analysis of biological materials is demonstrated by the determination of the main CB congeners present in human blood and of MeSO2‐CBs in seal blubber.

Element-selective detection of pesticides by gas chromatography—atomic emission detection and solid-phase microextraction

The analysis of samples contaminated by organic compounds, especially pesticides, is an important tool of environmental monitoring. A new isolation method has been developed for the determination of pesticides in environmental water samples using solid-phase microextraction (SPME). Thus, the extraction and preconcentration steps of sample preparation are focused in a single process step. For the determination of organophosphorus pesticides using SPME extraction and preconcentration steps a GC—atomic emission detection coupling system was used. This coupling technique is a very selective analytical tool. Element-characteristics chromatograms acquired by using different element emission lines can be obtained, enhancing the selectivity of the method in environmental monitoring, and they can be used to identify even unknown compounds in environmental samples. A fused-silica fiber coated with a polymer (polydimethylsiloxane) phase is used to extract organic compounds and transfer them into a GC injector for thermal desorption and analysis. Volatile pesticides can be efficiently isolated from aqueous environmental samples, as demonstrated for organophosphorus pesticides. This method shows a precision of 8–12% (R.S.D.), depending on the compound. Furthermore, it is capable of limits of detection in the ppb and sub-ppb range. The adsorption and desorption times to carry out the optimum equilibrium and thermodesorption conditions, have been optimized. Determination of pesticides in spiked river water samples with this technique is reported and a comparison of SPME to established extraction techniques, i.e. solid-phase extraction is also carried out. The results demonstrate the suitability of the SPME approach for analysis of these polar compounds.

Large-volume injections in gas chromatography-atomic emission detection: An approach for trace-level detection in water analysis

The ruggedness and analytical performance of on-line capillary gas chromatography-atomic emission detection (GC-AED) have been studied using 100-μl injections of sample solutions in ethyl acetate, via a loop-type interface. A series of organophosphorus compounds were selected as test analytes; they were monitored using the carbon, sulphur, nitrogen, chlorine, bromine and phosphorus channels. The system showed no flame-outs or other maintenance problems even after 300 large-volume injections. The analytical potential of the system, expressed in terms of repeatability, linearity and minimum detectable amount, was not affected and a 100-fold increase in analyte detectability, in terms of concentration units, compared with a conventional 1-μl injection was observed. As an application, GC-AED was combined off-line with solid-phase extraction. Several environmental contaminants were preconcentrated from river and tap water samples, and 20% (100 μl) of the ethyl acetate eluent were directly analysed. With a sample volume of only 10 ml, the detection limits of the organophosphorus pesticides typically were ca. 0.1 μg/l.

Rapid Identification of Benzothiazole in River Water With On-Line Solid-Phase Extraction-Gas Chromatography-Mass Selective Detection

Abstract Solid-phase extraction coupled on-line with gas chromatography-mass spectometry and off-line with gas chromatography-atomic emission detection is shown to be a rapid technique for the trace-level determination and provisional identification of (an) organic pollutant(s) in surface water.

A degradation procedure for determination of halogenated structural elements in organic matter from marine sediments

This study showed that an oxidative degradation method originally developed to study lignin structures can be used to investigate the presence of halogenated structures in high-molecular-weight organic matter from marine sediments. When the sediment sample itself, or the organic matter isolated from the sediment, was properly desalted prior to the degradation, remaining halides did not cause any halogenation reactions that interfered with the analysis of halogenated phenolic structures. Gas chromatography — atomic emission detection (GC-AED) and gas chromatography - mass spectrometry (GC-MS) analyses of degraded and methylated organic matter from Baltic Sea sediments showed that chlorinated, brominated, and iodinated analogues of 4-ethoxybenzoic acid methyl ester were present in all analysed samples. The chlorinated species have previously been identified upon degradation of humic substances from unpolluted freshwaters. The identification of brominated and iodinated structural elements represents the first indication of a large-scale bromination and iodination of high-molecular-weight organic matter in marine environments.

Characterization of an element-specific detector for combined gas chromatography—atomic emission detection

An element-specific detector using a capacitively coupled plasma developed recently for gas chromatography was characterized according to the accepted terms of gas chromatographic detectors. The most important detector parameters, sensitivity, linearity, limit of detection, linear range and selectivity, were determined for channels of four elements, carbon, chlorine, bromine and sulphur, with a view to potential applications. The parameters obtained were compared, as permitted by the different mechanisms of operation, with some common gas chromatographic detectors of similar application. The characteristics of the detector were evaluated independently of application.

Capillary gas chromatography—atomic emission detection: A useful instrumental method in pesticide residue analysis of plant foodstuffs

AbstractThe high selectivity of element‐specific atomic emission detection has proven suitable for screening analysis of plant foodstuffs for pesticide residues by capillary gas chromatography, especially for those foodstuffs which contain high levels of matrix compounds. The elemental composition of a peak can, furthermore, be examined by looking at the partial emission spectra recorded during a GC run. This instrumental feature prevents false positive signal interpretation as a result of high concentration levels of eluting matrix compounds.

Alkyltin speciation in sea water with on-line hydride conversion and gas chromatography—atomic emission detection

A method for the speciation of alkyltin pollutants in sea water combines solid phase extraction of organotin species from aqueous samples and an on-line hydride generation technique with gas chromatography, followed by element-specific detection for tin. Detection was performed using a microwave-induced plasma atomic emission detection system which provides a 0.5 pg detection limit for tin and a 3·10 4 tin-to-carbon selectivity ratio. Solid-phase extraction provides fast, simple analyte concentration while on-line hydride conversion improves chromatographic behavior and analyte recovery. This combination results in a method capable of measuring pg/ml levels of alkyltin species in the complex matrix of sea water.

Element‐selective atomic emission detection for capillary GC of metal‐containing compounds

AbstractElement‐selective GC detection by microwave‐induced plasma atomic emission spectroscopy has been used to examine a wide variety of compounds containing metals, non‐metals, and metalloids. “Recipes”, or new selective detection schemes for use with the software of the computer‐controlled system, have been developed for the selective detection of boron, aluminum, gallium, titanium, vanadium, chromium, manganese, rhenium, palladium, and platinum. Figures of merit including limits of detection, linear dynamic range, and spectral selectivity over carbon have been established for most of these elements. Gas chromatography – atomic emission detection (GC‐AED) has been applied to the selective detection of vanadium, nickel, and iron in metalloporphyrins present in crude oil, manganese‐selective detection of methylcyclopentadienylmanganese tricarbonyl (MMT) in gasoline, and titanium‐selective detection of reaction mixtures containing titanium catalysts or titanium boride molecular precursors.

Optimization of comprehensive speciation of organotin compounds in environmental samples by capillary gas chromatography helium microwave-induced plasma emission spectrometry

The operational variables are optimized for chromatographic resolution and detection limits. A comprehensive method for the determination of mono-, di-, tri-, and some tetraalkylated organotin compounds in water and sediments by gas chromatography-atomic emission detection (GC-AED) is developped. The absolute detection limit is about 0,05 pg (as Sn), and the calibration is linear over three decades.

Measurements using gas chromatography with coelution and dual-isotope atomic emission detection

Dual-isotope measurements by gas chromatography (GC)—atomic emission detection (AED) may enhance results for quantitative analyse. Adding a known amount of an isotopically labelled form of target analytes in each sample can compensate for irreproducibilities or uncertainties associated with sample pretreatments and sample loading. Similarly, fluctuations in AED temperatures, flows and interferants can be compensated via the added labelled forms if each target analyte and its isotopically labelled for coelute. Under these conditions they are subject to identical excitation environments and are measured from the same viewed volumes. Consequently, improved quantitative results may be attained by coellution in GC—AED methods which mimic isotope dilution.

Elemental Analysis by Gas Chromatography-Atomic Emission Detection for the Control of a Deuterated Derivatization Reagent

Abstract Methyl iodide is a derivatization reagent often used to methylate molecules with amine, hydroxyl or carboxylic groups before a gas chromatographic analysis. In order to improve the analytical qualities of quantitative determination by gas chromatography mass spectrometry, derivatization with reagents labelled with stable isotopes can be used. Deuteromethyliodide can be used instead of methyliodide to obtain labelled compounds easily detected, as far as the reagent is pure enough. This paper illustrates the use of the gas chromatography atomic emission detection coupling (GC-AED) for the study of the purity of a reagent labelled with deuterium (IC2H3) used for the derivatization of a new immunoenhancer (sodium ditiocarb - lmuthiolR) before the GC-MS determination of the parent drug and its methylated metabolite. The elements monitored simultaneously are: carbon (193.03 nm), hydrogen (656.3 nm), deuterium (656.04 nm), iodine (183.1 nm) and sulfur (180.7 nm). The chromatograms corresponding to these various elements obviously show the presence of compounds containing deuterium and I or hydrogen associated with iodine and make easier and faster the determination of the chemical pollution of the IC2H3 batch. The monitoring of the specific wavelength associated to the atomic emission of sulfur (180.7 nm) allows easy detection o f ditiocarb and its metabolite from the chromatogram made very complex by the reagent pollution.

Pesticide analysis by gas chromatography with a novel atomic emission detector

An atomic emission detector, consisting of a microwave-induced helium plasma and atomic emission spectrometer, has been used for the gas chromatographic analysis of pesticides. In principle, it is possiblr to detect any element in the periodic table (except helium) which can elute from a gas chromatograph. Detection limits for C, H, D, N, O, Br, Cl, F, S, Si, P, Sn and Hg were found to range from 0.1 to 75 pg/s with selectivities over carbon of 5000 or more. The gas chromatography—atomic emission detection system has been used for the detection and elemental characterization of 27 different pesticides by obtaining element-specific chromatograms for C, H, N, O, Br, Cl, F, P and S. By performing quantitative analysis for each element, it was possible to calculate the approximate empirical formulas for 20 different herbicides in two different mixtures. An extract from an apple doped with three pesticides was analyzed by gas chromatography—atomic emission detection.

Evaluation of a microwave cavity, discharge tube, and gas flow system for combined gas chromatography-atomic emission detection

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEvaluation of a microwave cavity, discharge tube, and gas flow system for combined gas chromatography-atomic emission detectionBruce D. Quimby and James J. SullivanCite this: Anal. Chem. 1990, 62, 10, 1027–1034Publication Date (Print):May 15, 1990Publication History Published online1 May 2002Published inissue 15 May 1990https://doi.org/10.1021/ac00209a013RIGHTS & PERMISSIONSArticle Views692Altmetric-Citations241LEARN 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 (2 MB) Get e-Alerts Get e-Alerts