Polycyclic aromatic hydrocarbons in milk powders marketed in Argentina and Brazil.

The aim of this study was to quantify polycyclic aromatic hydrocarbon (PAH) levels in milk powder samples commercialised in Argentina and Brazil during 2012. Thirty-one samples were available from the retail market. An HPLC method for the determination of PAHs was applied involving a clean-up step with silica cartridges. Recoveries were greater than 79% for all PAHs analysed. Reproducible determination with adequate detection and quantification limits (LOD and LOQ) were attained by HPLC with fluorescence detection for 14 PAHs. Acenaphthylene was determined with a UV-VIS detector. There is no significant difference in any PAHs or in the sum of them between the Argentinean and Brazilian samples. Therefore, the samples were evaluated together. The highest concentration of benzo(a)pyrene (BaP) detected was 0.57 µg kg⁻¹ in milk powder. Contamination of samples expressed as the sum of 15 analysed PAHs varied between 11.8 and 78.4 µg kg⁻¹ and as PAH4 (BaP, chrysene, benzo(a)anthracene and benzo(b)fluoranthene) was between 0.02 and 10.16 µg kg⁻¹. The correlation coefficient for PAH2 (BaP and chrysene) and PAH4 groups was 0.95, for PAH2 and PAH8 it was 0.71, and for PAH4 and PAH8 it was 0.83. All the samples were below the regulatory limit for BaP, but 65% of commercial milk powders do not comply with the European Union limit for PAH4. This is the first report of PAH contamination in powder milk from Argentina and Brazil.