Solid-phase microextraction coupled with microcolumn liquid chromatographyfor the analysis of amitriptyline in human urine

Solid-phase microextraction (SPME) is a solvent-free sample-preparation tec hnique that enables isolation and pre-concentration of analytes from a samp le on a thin film coating a fused-silica fiber. In this study SPME coupled with microcolumn liquid chromatography (micro LC) has been used for the det ermination of four tricyclic antidepressants (amitriptyline, imipramine nor triptyline, and desipramine) in human urine. SPME conditions which affect e xtraction efficiency were optimized, and under the optimum conditions the s ystem was a few hundred times more sensitive than direct LC analysis withou t SPME. For amitriptyline the detection limit was 3 ng mL(-1) and the calib ration curve was linear in the range of 5 - 500 ng mL(-1). The SPME-micro L C method has been applied to the analysis of amitriptyline in patients urin e.