Carbonyl compounds responsive 2,4-dinitrophenylhydrazine doped polydimethylsiloxane based membrane as alternative derivatizing strategy prior to in-tube solid phase microextraction coupled with capillary liquid chromatography analysis

In this work, a DNPH doped PDMS based membrane was developed to facilitate carbonyl compound derivatization. This membrane delivers DNPH in presence of carbonyl compounds to form hydrazones. Subsequently, the resulting hydrazones are preconcentrated, separated and detected by in-tube solid phase microextraction (IT-SPME) coupled on-line with capillary liquid chromatography (CapLC) with Uv-Vis diode array detection (DAD). The method proposed allowed the determination of the analytes up to 200 µg/L. The limits of detection were between 0.1 and 3.3 µg/L and intra-day precision and inter-day precision were lower than 7 % and 21 %.

The applicability of the strategy proposed was tested in environmental (waters and PM10) and biological samples (saliva). Samples were satisfactorily analysed with recoveries in the range of 68 %-80 %. The main advantages of the proposed strategy were the increment of DNPH stability, a reduction in the solutions and wastes required for the analysis and protection of the chromatographic column minimizing the excess of DNPH, thus providing a more sustainable analytical method to estimate carbonyl compounds.