Silk fiber for in-tube solid-phase microextraction to detect aldehydes by chemical derivatization

•Silk fiber was introduced as adsorbent material of SPME to detect aldehydes.•An online SPME-HPLC analysis system was built.•The SPME device provided good extraction efficiency for aldehydes after chemical derivatization.•Online analysis method was efficient to detect aldehydes in environmental samples.

Aldehydes are the potentially damaging pollutants in the environment, but it is difficult to be determined due to the low concentration level. Therefore, to accurate analysis of aldehydes, it is important for efficient sample preparation with selective enrichment and rapid separation. Environmentally friendly silk fiber as adsorbent material was directly applied to develop in-tube solid-phase microextraction for analyzing aqueous samples combined with high performance liquid chromatography. 2,4-Dinitrophenylhydrazine as a derivative reagent was used for chemical derivatization of aldehydes before extraction. Under optimum conditions, an online analysis method was built with the limits of detection in the range of 0.005-0.01 μg L−1 and the linearity in the range of 0.03-10 μg L−1. Three aldehydes were determined in two real samples, and the relative recoveries were in the range of 95-102%.