Fast off-line FPSE-HPLC-PDA determination of six NSAIDs in saliva samples

A fast off-line FPSE-HPLC-PDA method has been reported that allows simultaneous clean up and determination of six non-steroidal anti-inflammatory drugs (NSAIDs) in saliva samples from healthy volunteers. Particularly, furprofen, indoprofen, ketoprofen, fenbufen, flurbiprofen, and ibuprofen were chromatographically resolved. Benzyl paraben was chosen as the internal standard (BzPB, IS). These target compounds were successfully extracted from human saliva using fabric phase sorptive extraction (FPSE) and then analysed in the liquid chromatographic system by means of a short analytical column (Symmetry C18, 75 × 4.6 mm, 3.5 µm) using acetonitrile (AcN) and phosphate buffer (PBS, 30 mM; pH = 2.5) as the mobile phases. The method, validated through the calculation of all analytical parameters in accordance of International Guidelines, was applied to real saliva sample analysis collected from informed volunteers. The proposed approach that included the use of sol-gel polytetrahydrofuran (sol-gel PTHF) sorbent immobilized on cellulose support and C₁₈ stationary phase used in HPLC, showed high potential as a fast tool for future clinical and forensic applications. The herein reported results encourage potential future application of FPSE in the forensic field. Furthermore, the FPSE membrane was tested in dried saliva spot mode (DSS) in order to check its potential use as a sampling device, also for forensic applications.