Enhancing sensitivity of ion mobility spectrometry determination of aldehydes by in situ gas phase derivatization with dibutylamine

Abstract

A simple and fast method for the detection of aldehydes by headspace solid-phase microextraction (HS-SPME) based on nanostructure polypyrrole film coupled to ion mobility spectrometery (IMS) is described. The detection of aldehydes (pentanal, hexanal and heptanal) has been successfully accomplished using in situ chemical derivatization with dibutylamine as the derivatization reagent and IMS. The simultaneous and rapid detection of aldehydes is important, since elevated level of aldehydes is considered as the biomarker of different diseases. The highlight of this method was that it involved an amine nucleophilic addition reaction (which was often considered as Mannich reaction) in gas phase for enhancing IMS sensitivity of aldehydes. Dibutylamine was used as the derivatization reagent driven into the cell by using a syringe pump. The calibration graphs were linear in the range of 2.0–50.0 μg mL−1 with R 2 ≥ 0.99 in aqueous solutions and limit of detections were determined ≤ 1.8 μg mL−1. The RSD% values of the aldehydes determination was ≤ 8 %. Here we have demonstrated that other amine types (butylamine and tributylamine) can derivatize aldehydes and significantly improve the IMS sensitivity of tagged analytes. However, IMS spectrum is complicated by presence of the different product ions in the process.