Chlorinated paraffin screening in chocolate products and infant formula by planar solid phase extraction

A planar solid phase extraction with visual light detection (pSPE–Vis) was developed to screen chlorinated paraffins (CP) in chocolate products and infant formula. The analysis of selected persistent organic pollutants, such as polychlorinated biphenyls, excluded co-elution with CP. Separation and detection of CP in the target zone were obtained after simple-to-perform sample preparation, including a sulfuric acid treatment. The validation study for CP showed recoveries near 100%, a limit of decision of 7.8 ng g−1, and a limit of detection of 15.7 ng g−1 sample. The analysis of 63 samples from the German market revealed CP up to 260 ng g−1 in chocolate products and 54 ng g−1 in infant formula, which underlines the need for CP monitoring in food. The results are comparable with literature data and were evaluated in an interlaboratory test. The pSPE–Vis method is a cost-effective tool for total CP screening. Developed for initial screening, the method enables the detection of CP-contaminated samples, supporting their prioritization for more detailed follow-up analysis by HRMS.