Comprehensive two-dimensional chromatographic techniques for ultra-trace quantitative analysis of chlorinated dioxins in South Africa

Doctoral defense of Mrs. Jayne de Vos

Director: Chemistry, NMISA, Pretoria

When:        Friday 10 July 2015

Time:          11h30

Venue:       The Avogadro, Chemistry Building, Room 3.22

Jayne is the Director for Chemistry at the National Metrology Institute of South Africa (NMISA).  She has been involved with separation science and mass spectrometry for more than 20 years, working firstly on arson analysis while at the SAPS FSL and CSIR, and subsequently on the analysis of persistent organic pollutants while at NMISA, which she joined in September 2002.  She has a Master’s Degree in Applied Sciences: Chemistry that she received with distinction from the University of Pretoria in 2005.  She has now completed her Doctoral thesis in Chemistry, investigating the suitability of comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) as applied to chlorinated species for metrological measurement equivalence.

The thesis describes the method development and analysis of the seventeen toxic PCDD/F congeners, using GC×GC-TOFMS methodology.  The technique provides the selectivity (added peak capacity of GC×GC) and the sensitivity (focusing effect of the modulator) needed to meet the requirements as mandated for analysis in US EPA Method 1613B.  GC×GC-TOFMS provides a quick, convenient screen for numerous pollutant classes in a single analysis and can achieve detection limits comparable with US EPA Method 1613B requirements if sample extraction and clean-up are optimised to target PCDD/Fs.  The technique is ideal for application in developing countries where GC-HRMS is not available, and can be used to minimise costs by selecting only positive samples for further overseas analysis by GC-HRMS.  NMISA (and South Africa) now has a validated GC×GC-TOFMS dioxin analytical capability for low level (ultra-trace) quantitative screening of chlorinated compounds.  These are also the first metrologically validated results for PCDD/Fs using this methodology.

Contact person: Egmont Rohwer, Ph: (012) 420 2512