EFFECT OF HEATING THE INTERFACE ON CHROMATOGRAPHIC PERFORMANCE OF SOLID-PHASE MICROEXTRACTION COUPLED TO HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The effect of heating the injector was investigated for solid phase mi croextraction (SPME) coupled to high-performance liquid chromatography (HPLC). Analytes extracted with an SPME fiber were introduced to a HP LC separation column using the specially designed SPME-HPLC interface, where the analytes were desorbed with HPLC solvent mobile phase, The SPME fiber was heated in this interface to enhance desorption with a h eating wire coiled around the chamber using a dc power supply or a cap acitive discharge quick heating system. A temperature increase reduces the fiber coating-solvent distribution constant, and increases diffus ion rates, thereby enhancing the mass-transfer rate from the stationar y phase of the fiber to the mobile phase, A higher desorption rate red uces injection band width, and reduces peak broadening, thus enhancing the chromatographic performance, Desorption temperature was found to have a pronounced effect on the efficiency of desorption and separatio n, Increasing the desorption temperature significantly reduced carryov er on the fiber and enhanced the chromatographic resolution.