A novel approach to enhance the sensitivity of residual solvent analysis in static headspace gas chromatography (HS-GC) was developed. During the investigation of matrix effects on the recovery of residual solvents using HS-GC analysis, we found that the spiking of a particular additive in DMSO decreased the partition coefficients (K) of various common residual solvents, and thus substantially increased their concentrations in the gas phase (headspace). Further study also found that other compounds structurally similar to the additive could produce the unique matrix effect. By utilizing this matrix effect, the sensitivities of 1,1-dichloroethene, 1,1,1-trichloroethane, carbon tetrachloride, and 1,2-dichloroethane were increased by 67%, 67%, 80%, and 64%, respectively, compared to the analyte solution without the additive. Other residual solvents, which also showed enhancement of sensitivities, are ethanol, isopropanol, tert-butanol, methylene chloride and chloroform (enhanced up to 40%, 50%, 57%, 42%, and 66%, respectively). The results of the study indicates that intermolecular interactions, particularly hydrogenbonding interaction among the additive, residual solvent and diluent, may play a key role in this matrix effect, as the strongest effect is observed for analytes that possess strong hydrogen bond acidity and/or low basicity, i.e., alcohols and chlorinated compounds.
Chen Z, Huang WX, Yu S, Yang J, Liu H (2015) Utilization of a Matrix Effect to Enhance the Sensitivity of Residual Solvents in Static Headspace Gas Chromatography. J Chromatogr Sep Tech 6:289. doi:10.4172/2157-7064.1000289