Making a Case for Regenerating GC Liners in Industrial Wastewater Screening

Abstract

An environmental laboratory can save on GC inlet liners by regenerating the discarded ones after use in industrial wastewater extracts analysis. In this study, a simple regeneration method for used liners is described, and the results from those liners are compared with results obtained using new liners. The two types of liners were found to be interchangeable: the difference between the new and the regenerated liners data pairs plotted against their means had no unexpected outliers for 61 test organic pollutants. The results also show that the regenerated liners gave more precise measurements. Only the boxplots from regenerated liners had equal variance at 40 and at 80 μg L−1, the two common spiking levels for the 61 test organic pollutants. Surprisingly, the independence of new liners on the GC instruments was revealed when the relative percent deviations (RPD) were plotted against recoveries of the 61 test organic pollutants. In the plot, all 183 data points acquired using three different GC instruments fell on the same regression line: RPD = −1.07 [%Recovery] + 107. The same plot for regenerated liners produced a slope less in value than that of the new liners. The latter simply restates the better precision observed with regenerated liners.