Improved screening analysis of organic pollutants in river water samples by gas chromatography with atomic emission detection (GC-MIP-AED)

The potential of gas chromatography with a microwave-induced plasma atomic emission detector (GC-MIP-AED) for the screening analysis of trace organic components in river water samples is presented. The application of a commercially available GC-MIP-AED system to the screening of organic trace compounds has been greatly enhanced by the optimisation of the operating parameters to achieve the highest sensitivity for the simultaneous determination of C, H, Cl, Br, S and N. An improved evaluation of the chromatographic data has been carried out using several new self-developed macros, which allow the calculation of elemental response ratio factors (RRFs) and empirical formulas for the analysed compounds at different concentration levels. A significant dependence of the RRFs on the concentration level was found for hydrogen and sulphur, whereas the dependence of the RRFs on the type of compound is not significant, considering the analytical objective. Limits of detection in the pg-range can be obtained for the elements investigated. The calculation of empirical formulas and its precision is shown for several analytes over a wide range of concentration. At a concentration level close to the limit of detection the error of the formula calculation increases significantly. The performance characteristics of the GC-MIP-AED system in the presence of matrix interferences are assessed by measuring spiked river water samples.