Direct coupling of microcolumn liquid chromatography with in-tube solid-phase microextraction for the analysis of antidepressant drugs

The direct coupling of in-tube solid-phase microextraction (in-tube SPME) w ith microcolumn liquid chromatography (micro-LC) has been investigated for the analysis of antidepressants in human urine. The use of in-tube SPME has been clearly shown to be advantageous for the on-line coupling of the SPME method, as the sample pretreatment technique, with micro-LC as the separat ion technique. This is because much smaller amounts of the sample solutions , desorption solvents and the mobile phase are required compared with conve ntional SPME-LC systems. The parameters for preconcentration have been inve stigated for the extraction capillary with the newly developed 'wire-in-tub e' configuration.