“…The extraction is based on partitioning of the analyte between the organic phase on the fused silica fibre and the analyte. Many factors, such as pH, temperature, salt concentration and stirring, affect the equilibrium constant and the equilibration time [7][8][9][10][11][12]. The major disadvantages of SPME in quantitative analysis are low recovery (low sensitivity), the frequent inability of the fibre to withstand a complete run (standards + blanks + QC samples + patient samples) and the impossibility of treating samples in an organic solvent.…”