Markes thermal desorption instruments used for environmental monitoring | Two new influential papers

Markes International's thermal desorption instrumentation has been used for research recently published in two influential journals:

Determination of phosphine and other fumigants in air samples by thermal desorption and 2D heart-cutting gas chromatography with synchronous SIM/Scan mass spectrometry and flame photometric detection

Svea Fahrenholtz, Heinrich Hühnerfuss, Xaver Baur, Lygia Therese Budnik

Journal of Chromatography A, 1217 (2010) 8298–8307

Abstract
Fumigants and volatile industrial chemicals are particularly hazardous to health when a freight container is fumigated or the contaminated material is introduced into its enclosed environment. Phosphine is now increasingly used as a fumigant, after bromomethane – the former fumigant of choice – has been banned by the Montreal Protocol. We have enhanced our previously established thermal desorption–gas chromatography–mass spectrometry (TD-GC–MS) method by integrating a second gas chromatographic dimension and a flame photometric detector to allow the simultaneous detection of phosphine and volatile organic compounds (VOCs), providing a novel application. A thermal desorption system is coupled to a two dimensional gas chromatograph using both mass spectrometric and flame photometric detection (TD-2D–GC–MS/FPD). Additionally, the collection of mass spectrometric SIM and Scan data has been synchronised, so only a single analysis is now sufficient for qualitative scanning of the whole sample and for sensitive quantification. Though detection limits for the herewith described method are slightly higher than in the previous method, they are in the low µLm−3 range, which is not only below the respective occupational exposure and intervention limits but also allows the detection of residual contamination after ventilation. The method was developed for the separation and identification of 44 volatile substances. For 12 of these compounds (bromomethane, iodomethane, dichloromethane, 1,2-dichlorethane, benzene, tetrachloromethane, 1,2-dichloropropane, toluene, trichloronitromethane, ethyl benzene, phosphine, carbon disulfide) the method was validated as we chose the target compounds due to their relevance in freight container handling.

Further details: http://tinyurl.com/68oc3on

Halogenated hydrocarbon pesticides and other volatile organic contaminants provide analytical challenges in global trading

Lygia T. Budnik, Svea Fahrenholtz, Stefan Kloth and Xaver Baur

J. Environ. Monit., 2010, 12, 936–942

Abstract
Protection against infestation of a container cargo by alien species is achieved by mandatory fumigation with pesticides. Most of the effective fumigants are methyl and ethyl halide gases that are highly toxic and are a risk to both human health and the environment. There is a worldwide need for a reliable and robust analytical screening procedure for these volatile chemicals in a multitude of health and environmental scenarios. We have established a highly sensitive broad spectrum mass spectrometry method combined with thermal desorption gas chromatography to detect, identify and quantify volatile pesticide residues. Using this method, 1201 random ambient air samples taken from freight containers arriving at the biggest European ports of Hamburg and Rotterdam were analyzed over a period of two and a half years. This analytical procedure is a valuable strategy to measure air pollution from these hazardous chemicals, to help in the identification of pesticides in the new mixtures/-formulations that are being adopted globally and to analyze expired breath samples after suspected intoxication in biomonitoring.

Further details: http://tinyurl.com/62whqop