A facile and fully automated on-fiber derivatization protocol for direct analysis of short-chain aliphatic amines using a matrix compatible solid-phase microextraction coating

Abstract

Solid-phase microextraction (SPME) analysis of short-chain aliphatic amines (C-3-C-6) in aqueous solutions was investigated using pentafluorobenzaldehyde (PFBAY) as on-fiber derivatization reagent. A standard gas generating vial agent was used for on-fiber loading of the derivatization agent so as to avoid the need for its regeneration at each derivatization cycle. Several parameters such as loading time, reaction temperature, and reaction/extraction time were optimized for headspace and direct sampling in aqueous solutions. Three different coating chemistries were tested and their performances compared in order to achieve the best compromise between sensitivity and analysis throughput. The newly developed PDMS/DVB/PDMS coating showed superior performance in terms of extraction efficiency while the capability to prevent on-fiber degradation of the derivatizing products. The optimized method was used for quantitation of short-chain aliphatic amines in aqueous samples and provided detection limits in the low ppb range for all the amines tested with accuracy values between 79 and 120%. The method was applied towards the analysis of environmental water samples and the accuracy of the results was evaluated by different calibration approaches.