Photochemical sample treatment: a greener approach to chlorobenzene determination in sediments

Due to worker׳s exposure, solvent and stationary phases׳ consumption, sample purification is one of the most polluting steps in analytical procedures for determination of organic pollutants in real samples. The use of photochemical sample treatment represents a valid alternative methodology for extracts clean up allowing for a reduction of the used amount of organic solvents. In this paper we report the first application on the photolytic destruction of organic substances to eliminate some of the interferences in the analysis of Chlorobenzenes in sediment samples. The method׳s efficiency and robustness were compared with classic silica column purification process currently used in clean up procedures in sediment analysis. Quality parameters such as recovery, linearity and reproducibility were studied. The entire procedure was validated by three replicate analysis of spiked real sediment sample. The quantification limits (LOQ) obtained by us ranged from 1.0 to 2.3 ng g(-1), while the detection limits (LOD) were of 1.0 ng g(-1). The RSD for each congener was below 10% and recoveries were in the range 95-130%. Results based on the analysis of real samples showed similar or improved detection thresholds and pointed out the advantages of the photochemical methodology in terms of costs, use of chemical substances and operator׳s safety according to Green Analytical Chemistry principles.