Determination of volatile organic compounds in water by purge-and-trap gas chromatography coupled to atomic emission detection

In this study, the potential of the combination of atomic emission detection (AED) with conventional purge-and-trap gas chromatography for the determination of 16 volatile organic compounds (VOCs) in water was investigated. The advantages of element-specific detection that are proprietary to GC-AED were shown, i.e. differentiation between the halogens, substance independent calibration and calculation of empirical formulas. For element-specific detection, four wavelengths were monitored, corresponding to carbon (495.72 nm), hydrogen (486.13 nm), chlorine (479.45 nm) and bromine (478.55 nm) emission. Calibration standards were prepared following a special protocol developed in our laboratory in order to avoid sample losses due to the high volatility of most of the VOCs. The reproducibility within batch falls generally within a range of 5% relative standard deviation (R.S.D.). Only the highly volatile analytes showed values up to 25% R.S.D. The method was validated by analyzing standards at different concentration levels.