Effect of Heating the Interface on Chromatographic Performance of Solid Phase Microextraction Coupled to High-performance Liquid Chromatography

Abstract

The effect of heating the injector was investigated for solid phase microextraction (SPME) coupled to high-performance liquid chromatography (HPLC). Analytes extracted with an SPME fiber were introduced to a HPLC 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 heating wire coiled around the chamber using a dc power supply or a capacitive discharge quick heating system. A temperature increase reduces the fiber coating–solvent distribution constant, and increases diffusion rates, thereby enhancing the mass-transfer rate from the stationary phase of the fiber to the mobile phase. A higher desorption rate reduces 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 separation. Increasing the desorption temperature significantly reduced carryover on the fiber and enhanced the chromatographic resolution.