Coupling needle trap devices with gas chromatography-ion mobility spectrometry detection as a simple approach for on-site quantitative analysis.

This study presents needle trap device (NTD) coupled with a portable gas chromatography-ion mobility spectrometry detection system (NTD-GC-IMS) as an advantageous, simple, cheap and reliable approach for on-site quantitative analysis. The NTD-GC-IMS system was evaluated using α-pinene, limonene and acetone as analytical models. Results showed satisfactory response stability (intra and inter-day relative standard deviation (RSDs)<10%), as well as limits of detection (LODs) comparable to those provided by conventional benchtop instruments (LODs<0.7ng). Additionally, this methodology, together with solid phase microextraction (SPME-GC-IMS), was successfully used for on-site monitoring of temporal emissions of α-pinene by a pine branch at different times during the same day. Quantitative analysis was satisfactorily accomplished in a significantly short period of time (330s) owing to the low detection limits that IMS detection provides.