Trace impurities in solvents commonly used for gas chromatographic analysis of environment samples

Distilled-in-glass and pesticide grade solvents commonly used in analyses of environmental samples for organic compounds at trace concentration levels were condensed 2000 fold and analyzed by gas chromatography, gas chromatography- mass spectrometry and selected ion monitoring. Cyclohexane, methylene chloride and methanol solvents each contained an estimated total of 1–150 ng of organic impurities per ml of uncondensed solvent. Impurities identified by mass spectra included phthalate esters, n -hydrocarbons and chrlorinated ydrocarbons; however no solvent contained all of these impurities. Pesticide grade solvents contained up to 21 components with maximum concentrations per single component of 30–50 ng/ml in the uncondensed solvent. Distilled-in-glass grade solvents had fewer and lesser amounts of similar impurities, and were found to be the most suitable for trace organic analysis.