Microextraction in Packed Syringe (MEPS) Utilizing Methylcyanopropyl–Silarylene as Coating Polymer for Extraction of Drugs in Biological Samples

Microextraction in packed syringe (MEPS) is a new technique for miniaturised solid‐phase extraction that can be connected online to GC or LC. In this work, a liquid polymer was used as coating polymer on a filter in a 10 µL and 250 µL syringe to handle small sample volumes (≤10 µL plasma). Ropivacaine in plasma samples was used as model substance. The validation of the methodology showed that the accuracy values of quality control samples (QC) were in the range of 103%–114% for GC‐MS, and 98–101% for LC‐MS‐MS. The precisions, given as relative standard deviation (R.S.D.) were in the range 1.9 to11% for Inter‐ and intra‐day precisions. The standard curves were obtained within the concentration ranges 5‐2,000 nM in human plasma samples. The regression correlation coefficients (R2) for plasma samples were 0.99 for all runs using GC‐MS and LC‐MS‐MS.