In-pipette-tip natural-feather-supported liquid microextraction for conveniently extracting hydrophobic compounds in aqueous samples: A proof-of-concept study

In this study, a novel in-pipette-tip natural-feather-supported liquid microextraction (NF-SLME) method was developed for conveniently extracting hydrophobic compounds in aqueous samples. Natural feathers were used as the support medium of an oily extraction solvent and an in-pipette-tip extraction device was simply constructed with the cost less than 0.1 CNY. The whole extraction process could be conveniently conducted with a pipettor. As a proof of concept, the in-pipette-tip NF-SLME method was applied to extract antidepressants in urines. The best extraction recoveries were obtained when the extraction solvent was 15 μL of n -octanol, the pH of the sampling solution was 10.0, the desorption solution was 200 μL of acetonitrile, and the numbers of cycles of drawing solution in/out for extraction and elution were 5 and 2, respectively. Coupled with high-performance liquid chromatography–ultraviolet, a quantification method was validated in ranges of 0.05–10 μg/mL with satisfactory linearities (R 2  ≥ 0.988). The limits of quantification were calculated to range from 0.032 to 0.048 μg/mL, which is adequate for antidepressant analysis in urine. The potential of the in-pipette-tip NF-SLME method was further illustrated by the successful extraction of triazole pesticides and androgenic steroids with good recoveries.