Comprehensive two-dimensional gas chromatography time of flight mass spectrometry (GC×GC-TOFMS) for environmental forensic investigations in developing countries

Abstract

a b s t r a c tThe disposal and dumping of toxic waste is a matter of growing concern in developing countries, including South Africa. Frequently these countries do not possess access to gas chromatography-high resolution mass spectrometry (GC-HRMS) for the determination of persistent organic pollutants (POPs). This publication describes an alternative approach to the investigation of toxic waste using comprehensive gas chromatography coupled to time of flight mass spectrometry (GC Â GC-TOFMS). The technology permits both comprehensive screening of toxic samples for numerous classes of organic pollutants and also quantitative analysis for the individual compounds. This paper describes the use of this technique by analysing samples obtained from a hazardous waste treatment facility in South Africa. After sampling and extraction the samples were analysed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and four dioxin-like non-ortho substituted polychlorinated biphenyls (PCBs). The quantitative values, as well as detection limits, obtained using the GC Â GC-TOFMS methodology compares well with those obtained using GC-HRMS; the accepted benchmark technology for this analysis. Although GC Â GC-TOFMS is not a target compound analytical technique (as is GC-HRMS), it is possible to obtain information on numerous other classes of organic pollutants present in the samples in one analytical run. This is not possible with GC-HRMS. Several different column combinations have been investigated for handling very complex waste samples and suggestions are presented for the most suitable combination.

Gas Chromatography in Environmental Sciences and Evaluation of Bioremediation

“…Panić and Górecki reviewed GC×GC in environmental analyses and monitoring and they indicated that the main challenge in environmental analysis is that the analytes are usually present in trace amounts in very complex matrices (Panić & Górecki, 2006). In overcoming this problem, GC×GC-MS is a very powerful and attractive system that has been successfully applied for powerful identification of polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) (de Vos et al, 2011), polychlorinated biphenyls (PCBs) (Focant et al, 2004;Hoh et al, 2007), polychlorinated naphthalenes (PCNs) (Korytár et al, 2005), nonyl phenol (NP) (Eganhouse, et al, 2009), benzothiazoles, benzotriazoles, benzosulfonamides (Jover et al, 2009), Cl-/Br-PAH congeners (Ieda et al, 2011), pharmaceuticals and pesticides (Matamoros et al, 2010) in complex environmental samples.…”

Establishing an alternative method for the quantitative analysis of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans by comprehensive two dimensional gas chromatography–time-of-flight mass spectrometry for developing countries

“…The National Metrology Institute of South Africa (NMISA), in collaboration with various institutions, launched the project towards a comprehensive screening method for multiple classes of persistent organic pollutants (POPs) in one run using Comprehensive Gas Chromatography-Time-of-Flight Mass Spectrometry (GC×GC-TOFMS) [5,6]. There are numerous challenges that have to be overcome with this approach.…”

“…It is expected that the selectivity lost due to low resolution mass spectrometry (vs HRMS) will be offset by the higher selectivity of the extra gas chromatographic dimension. Moreover, as full range mass spectral data are always acquired (detailed full range mass spectral acquisition for selected classes of POPs is described in a previous paper [6]), it is not a target compound technique such as single ion monitoring (SIM), and is ideal for screening for multiple classes of environmental pollutants in a single analysis [1,[10][11][12][13][14]. Retrospective data mining of archived data will be possible when future focus turns to new target compounds, e.g., the brominated dioxins.…”

“…Chief amongst these being the separation of the PCDD/F congeners from each other and from matrix interference and the sensitivity considerations to allow accurate quantitative measurement down to 500fg for 2,3,7,8-TCDD as required by US EPA Method 1613 [7]. The ultimate goal of this methodology would be a comprehensive screening method for multiple classes of POPs in one run [5,6] coupled with accurate quantitation of important pollutant classes. This paper focuses on PCDDs and PCDFs and describes the analysis of the seventeen priority PCDD/F congeners mandated by EPA Method 1613 [7].…”

Experience in South Africa of combining bioanalysis and instrumental analysis of PCDD/Fs

“…These methods not only screen for a variety of potentially harmful compounds, but can also accurately quantify POPs at the concentrations required by statutory organizations in first world countries (9,10,11). Such methodologies must be affordable, simple and robust, because in addition to limited funding, in many developing countries there is also a shortage of qualified personnel that can routinely conduct these analyses.…”