Photochemical sample treatment for extracts clean up in PCB analysis from sediments

Sample purification can be considered the most polluting step of the whole analytical process for PCBs determination in sediment samples. The use of photochemical sample treatment represents an alternative methodology for extracts clean up allowing for a reduction of the used amount of organic solvents. The first application of a photochemical sample treatment for the selective removal or reduction of organic substances interfering with PCBs analyses in sediments is reported. The method's efficiency and robustness were compared with currently used chromatographic purification. Quality parameters such as recovery, linearity and reproducibility were studied. The entire procedure was validated by four replicate analysis of certified reference sediment. The quantification limits (LOQ) obtained by us ranged from 1 to 3.1 ng g−1. The RSD for each congener was below 15% and recoveries were in the range 40–130%.Results based on the analysis of real and certified samples showed similar or improved detection thresholds and pointed out the advantages of the photochemical methodology in terms of costs and environmental friendly conditions.

► This is the first application of photochemical sample treatment for reduction of interfering with PCBs analyses in sediment. ► Photochemical purification is a low cost, rapid and reliable approach. ► Photochemical processes do not use solvents and can be applied simultaneously to several samples. ► Best results were obtained irradiating the sample for 3 h by UV at 365 nm and bubbling oxygen.