Vacuum ultraviolet (VUV) detector for gas chromatography (GC) provides qualitative spectral information from 125 nm to 240 nm. In this article, this information was applied to facilitate the development of a GC method for challenging pharmaceutical applications. Seven organic solvents were screened for trace level water content using VUV detection at 168 nm, and the results were used to identify n-hexane as a suitable diluent for 4-ethoxy-1,1,1-trifluoro-3-buten-2-one (ETFBO), a water reactive compound. Selective detection of compounds of interest was demonstrated by varying detection wavelengths. All compounds were detected at 145 nm except for one unknown impurity, which co-eluted with n-hexane solvent. This impurity was detected at 225 nm, where n-hexane has no absorbance. In addition, the VUV spectra were used to: 1) accurately track peaks during early method development; 2) detect co-eluting peaks; 3) match peak identity in a sample vs. a standard; and 4) assess peak purity. With the universal detectability, qualitative spectral information and ease of use, VUV will become a versatile tool for GC for both method development and routine analysis.
Keywords: Detection of water in organic solvents; Gas chromatography; Peak purity assessment; Peak tracking; Pharmaceutical applications; Vacuum ultraviolet detection.
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