Molecular formula determination of halogenated compounds in environmental samples using gas chromatography and atomic emission dection

Abstract

Abstract. Atomic emission spectroscopy coupled with capillary gas chromatography (GC) has been evaluated for molecular formula determination of several chlorinated and brominated compounds present in three environmental samples. Variations in elemental responses due to compound type, poor chromatographic resolution, and small signals relative to the background were all found to complicate molecular formula calculations. About 20% of the calculated molecular formulas presented in this paper agreed with theoretical values. For most applications, identifications based solely on GC coupled with atomic emission detection (AED) are not sufficiently accurate. However, the combination of elemental information derived from a GC-AED analysis with complementary data obtained from other detection techniques results in a strong analytical tool for analyte identification.

Simultaneous Element-Selective Detection of C, F, Cl, Br, and I by Capillary Gas Chromatography Coupled with Microplasma Mass Spectrometry

“…No fluorinated compounds were detected. Previous work with this extract have been performed with GC-AED and GC-MS [14,15]. These have shown that peaks number 1 and 2 were trichloro-trimethylbenzenes and peak number 3 was a bromo-dichloro-methylbenzene.…”

Determination of brominated alkylbenzenes in nickel industry sludge by capillary gas chromatography

“…For GC-AED, previous studies have demonstrated that response in the bromine-selective mode is dependent only on the amount of bromine introduced into the plasma [8,9,11,12,[18][19][20][21]. Thus, bromine-responses are almost independent of molecular structures and this has been demonstrated for a broad range of different compounds including brominated alkylbenzenes [15,16]. Based on this, quantification of the brominated alkylbenzenes identified above was accomplished rapidly with a single calibration curve for bromine (Table I).…”

“…Thus, although the knowledge obtained by GC-AED was limited to elemental information, this effectively complemented the results from GC-EIMS. In addition to the qualitative elemental information, GC-AED may be utilized for the estimation of molecular formulas [15,16].In the present work however, this was of relatively little interest because most of the brominated alkylbenzenes coeluted with chlorinated matrix constituents. Thus, poor accuracy was expected for the molecular formulas estimated by GC-AED.…”

“…This information in combination with the GC-EIMS resuits discussed above was sufficient to positively identify C9H8BrCI3 in peak No. 15 and C9H9BrC12 in peak No. 11.…”

Towards the use of ICP-OES for the elemental analysis of organic compounds such as glucosamine

“…The identication of organic compounds by atomic emission spectrometry (AES) through determination of their empirical formula has so far only been carried out by gas chromatography coupled to a microwave induced plasma (MIP). [10][11][12][13][14][15][16][17][18] However, this approach has a number of drawbacks. It is only applicable to relatively volatile thermally-stable compounds, thereby requiring derivatisation of non-volatile analytes, which signicantly increases the analysis time and sources of error.…”