Determination of the sum of short chain chlorinated n-alkanes with a chlorine content between 50% and 67% in sediment samples by GC–ECNI-MS and quantification by multiple linear regression

Abstract

A method for the quantification of the sum of short chain chlorinated paraffins (SCCPs) by GC–ECNI-MS was developed. This method is suited to the special demands of environmental sediment analysis using an approach of sum determination by multiple regression quantification and is independent of the chlorine content as well as robust against changes in C-number distribution of the SCCPs to be analysed. The method is based on the integration of the signals for two selected m/z values (375 and 423) over the full retention range of the SCCPs. The calibration is performed using three synthetic mixtures representing the variety of SCCP-mixtures as found in environmental samples as well as in technical mixtures. Quantification is performed using a multiple linear regression calibration with two selected m/z value signals achieving an LOQ of 0.6μg/g sediment.The proposed quantification procedure for sediments was verified by 16 independently prepared and differently composed SCCP-mixtures mimicking a variety of sediment samples quoted in literature.For the analysis of the sediment samples a two-step clean-up was applied comprising a column chromatographic clean-up and GPC.The method allows for a standardized analysis according to the European water framework directive, especially in the case of trend monitoring of sediments.