Determination of polycyclic aromatic hydrocarbons (PAHs) and total fats in human milk

A sensitive and reliable analytical method was developed for the simultaneous extraction of PAHs and total fats and their determination in the human milk. The method involved a liquid-liquid extraction of PAHs and fats, followed by the gravimetric determination of the latter. PAHs were separated from lipids by size exclusion chromatography eluting with methylene chloride and analysed by gaschromatography coupled with mass spectrometry (GC/MS). The recovery of analytes was in the range of 42-101% and agreed well with their boiling temperatures (R2=0.779). Precision of the method was found between 7.6 and 19%. Quantification and detection limits for individual PAHs ranged from 0.011 to 0.032 and from 0.006 to 0.022 microg/Kg milk (wet weight), respectively. Quantification limit for the total fat determination was 0.26 g/Kg milk (wet weight). This procedure, applied to milk samples of ten healthy, non-smoking, Italian primiparae, living in rural or low-traffic zones, allowed for the identification and quantitative determination of naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, benzo(b)fluoranthene and benzo(k)fluoranthene in the mean concentration range 0.114-6.95 microg/Kg milk (wet weight). The most volatile compounds, which were not investigated elsewhere, were found at much higher concentrations than those observed for the others. No relation was found between PAH and total fat concentrations.