Performance of GC-MS and MOSES II, a hybrid modular sensor system, for the quantitative detection of the evaporation of the insect repellent N,N-diethyl-m-toluamide from two different matrices.

摘要

The purpose of this work was to determine the evaporated amount of N,N-diethyl-m-toluamide (DEET), a commonly used insect repellent, from two different matrices medium chain triglycerides (MCT) and Polyethylene glycol 400 (PEG), with GC with mass sensitive detection (GC-MS) and a hybrid modular sensor system (MOSES II). Thus, the binary mixtures are equilibrated at 80 degrees C for 45 min and then an aliquot of this headspace is analyzed by GC-MS and a sensory system consisting of an array of eight metal oxide sensors and eight quartz crystal microbalances. Both analytical methods allow a sensitive detection of even small amounts of DEET in the headspace from binary mixtures with the MCT or PEG, respectively. The two additives are found to be very different concerning their behavior to the vapor phase; i.e., the lipophilic (MCT) delivers an almost constant headspace of DEET, while the hydrophilic matrix PEG releases smaller amounts of DEET, which continuously decrease when a multiple headspace extraction is performed. Furthermore, the results reveal that both analytical methods lead to comparable results with the MCT/DEET mixtures whereas differences were seen with mixtures containing PEG. This can be attributed to the interaction of volatile portions of PEG with the sensors of the MOSES II.