In-syringe dispersive micro-solid phase extraction using carbon fibres for the determination of chlorophenols in human urine by gas chromatography/mass spectrometry

• Carbon fibres (CFs) are synthesized and evaluated as sorbent.
• The synthesis is simple, cheap and environmental friendly.
• CFs are used for the extraction of chlorophenols (CPs) from urine samples.
• The analytical method allows the determination of CPs in the low μg/L range.

In this article, carbon fibres (CFs) are presented as sorbent material for the dispersive micro-solid phase extraction of twelve chlorophenols from urine samples. CFs are synthesized by a reagentless and green procedure consisting of heating raw cotton, a natural precursor, at high temperature (400 °C) in an inert atmosphere (Ar) during 2 h. The resulting fibres, which present good water dispersibility, are finally loaded on an in-syringe device. This device, which integrates the extraction and final elution of the analytes, is disposable and it is adapted to process low sample volumes. Working at the optimum conditions, the extraction procedure in combination with gas chromatography/mass spectrometry allows the determination of the analytes in urine at the low μg/L range. In fact, the limits of quantification (LOQs) of the analytes were in the interval from 1 μg/L to 2.5 μg/L with precision values, expressed as relative standard deviations (RSD), better than 13%. Relative recovery values, ranging from 74.5% to 113%, demonstrate the applicability of the proposed method.