SOLVENT-FREE SAMPLE INTRODUCTION FOR SUPERCRITICAL-FLUID CHROMATOGRAPHY USING POLYMER-COATED FIBERS

A solvent-free sample introduction method for supercritical fluid chromatography that uses polymer coated fused silica fibers results in very stable baseline and high efficiency separations. The method has two steps: first, a fiber is exposed to a prepared mixture of target analytes or a sample so that the polymeric coating absorbs analytes, and second, the fiber is placed inside a piece of tubing connected to the column of a supercritical fluid chromatograph. The supercritical fluid carrier extracts analytes from the coating and transfers them onto the head of the column. Pressure programmed separation follows. The method was tested on high molecular weight and polar analytes using 100 and 50 mu m i.d. capillary columns. Fibers with a polydimethylsiloxane coating were used to extract hydrophobic analytes, and fibers with a polyacrylate coating were used to extract more polar compounds.