Targeted Analysis and Accurate Profiling of Volatiles and Semi-volatiles in High Complexity Samples

GC×GC-HRMS is one of the most powerful tools available to analytical chemists for the targeted analysis and accurate profiling of volatiles and semi-volatiles in samples of high complexity. This technique combines the excellent resolving power granted by two-dimensional separations with accurate mass measurements that provide a substantial advantage for identity confirmation. It is therefore not surprising that GC×GC-HRMS is increasingly more accepted in labs dealing with challenging analytical requests in very complex matrices such as, for instance, environmental and food analysis.

JSB recently investigated the use of GC×GC with Zoex thermal modulation coupled to an Agilent QTOF detector for quantification of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). These compounds are synthetic chlorinated compounds banned or restricted due to their toxicity to humans and impact on the environment but, being persistent pollutants, are still present as residues in soil, water, food etc. Their identification and quantification is of great importance for environmental and food safety since they represent a risk even at very low level. The QTOF grants wide operational flexibility allowing EI and CI acquisition, as well as MS/MS capability. In this example JSB selected the NCI to obtain higher sensitivity for the halogenated compounds. The results obtained for linearity and repeatability show that GC×GC with thermal modulation and QTOF are robust and provide performance suitable for reliable identification and quantification at low concentrations.