Nanofibers mat-based solid-phase extraction method for the pretreatment of urine samples and its application in the primary study on the disposition of nonylphenol after long-term low-level exposure in rats

- An eco-friendly solid-phase extraction method based on nanofibers mat was developed.
- Noticeable less consumption of sorbent and organic solvent was required.
- Simple but effective extraction of nonylphenol from rat urine samples was achieved.
- Remarkable lower detection limit, better precision and accuracy was confirmed.
- Biomonitoring of simulated real nonylphenol exposure was achieved preliminarily.

A method was established for the analysis of nonylphenol (NP) in rat urine samples based on a solid-phase extraction (SPE) procedure with an amino functionalized polyacrylonitrile nanofibers mat (NH2-PAN NFSM) as sorbent coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The calibration curves prepared in three different days showed good linearity over a wide range of NP concentrations from 0.1 to 100.0 ng/mL. It was remarkable that the proposed NH2-PAN NFsM based SPE method showed superior extraction efficiency with the consumption of only 4 mg of sorbent and 500 μL of eluent. The eluent without any further concentration was directly analyzed by HPLC-MS/MS. As a result, a simple and effective sample preparation was achieved. In addition, the notable lower detection limit (LOD) of 0.03 ng/mL revealed the excellent sensitivity of the proposed method in comparison with that in literatures. The recoveries ranged from 85.0% to 114.8% with the relative standard deviations (RSDs) ranging from 7.5% to 13.7%, which were better than or comparable to those from the published methods, suggesting high accuracy of the proposed method. The proposed method was applied in primary study on the disposition of nonylphenol after long-term low-level exposure in rats, providing information for health risk assessment on the real scenarios of NP exposure. NH2-PAN NFsM shows great potential as a novel SPE sorbent for the analysis of biological samples.