The Column - November 2008 - (Page 25)

November 2008 www.thecolumn.eu.com The Column Q&A The Rise and Rise of Multidimensional GC The Column’s Janet Kelsey spoke with Marco Koenen and Ed Ledford of Zoex about the rising popularity of multidimensional gas chromatography. Multidimensional gas chromatography is a fairly new technique compared with those conventionally used in chromatography. Can you explain why its popularity is on the rise? Multidimensional GC (MDGC) is becoming popular with many GC analysts because of the growing realization that conventional one-dimensional techniques are not sufficient for the analyses of even “moderately” complex mixtures (which describes most samples) and because of the ease of integration and operation of MDGC within existing GC systems. Like all new technologies that come onto the market, the uptake of MDGC commercially over the last 15 years has been dominated by GC opinion leaders and those at the forefront of GC research. MDGC technology has expanded and the term is now recognized to include “comprehensive GC” (total transfer of analytes from primary to secondary column) and “heart-cutting” (partial transfer of analytes from primary through secondary column). The versatility of multidimensional GC, together with simple integration into existing GC systems, today caters to all GC analysts, from laboratory technicians to academic researchers. Moreover, legislation is driving detection limits to lower concentrations and economic demand for higher information throughput is also contributing to the growing popularity of Contact: Marco Koenen E-mail: info@zoex.eu MDGC. Because analysts are regularly faced with troublesome co-eluters, active compounds and more complex matrices, an increasing number of GC users are turning to MDGC. Why should MDGC be considered in preference to GC? Surprisingly, MDGC is almost always useful for any analysis requiring separation of more than about 37 peaks. This is because of the statistics of peak overlap in conventional GC: at about 37 peaks, statistically speaking, there will be at least one difficult coelution. At 100 separated peaks, the game is over. Analysts are facing an MDGC problem and probably a comprehensive GC problem at that level of complexity. There are several sample types where MDGC, and particularly comprehensive GC, currently find popularity: petroleum and refinery products, fragrance and flavour extracts, forensics and clinical toxicology (metabolomics) and environmental applications, which include pesticides and persistent organic pollutants (POPS). But essentially all applications of GC, other than simple major component analysis, benefit from MDGC techniques. Analysts who perform data analysis both using MDGC and GC will see a whole range of benefits, which include up to 30 times more resolving power than GC, easier method development, higher sensitivity for low-level target analytes, 23 http://www.thecolumn.eu.com

Table of Contents for the Digital Edition of The Column - November 2008

The Column - November 2008
Contents
Smoke Signals
News
Incognito Method "Non" - Specificiations!
Market Trends and Analysis Market Profile: Capillary Electrophoresis
Simple Differentiation of Black Tea Samples Using a Chemometric Approach
Q&A: The Rise and Rise of Multidimensional GC

The Column - November 2008