Analysis of polycyclic aromatic hydrocarbon metabolites in cow's milk by liquid-liquid extraction and synchronous room-temperature fluorescence spectroscopy

We present the first application of synchronous room-temperature fluorescence spectroscopy to the analysis of monohydroxy-polycyclic aromatic hydrocarbons in milk samples. Metabolites are extracted from milk samples by a two-step liquid-liquid extraction procedure. The small sample (400 mu l) and extracting solvent (1.4 ml) volumes facilitate the simultaneous extraction of numerous samples via an environmentally friendly procedure, which is well-suited for routine monitoring of numerous samples. Quantitative analysis is carried out in the sample extract without the need for previous chromatographic separation. Excellent recoveries and limits of detection at the parts-per-billion level were obtained for 2-hydroxyfluorene, 6-hydroxychrysene, 1-hydroxypyrene and 3-hydroxybenzo[a]pyrene. The non-destructive nature of the new method provides ample opportunity for metabolite confirmation via chromatographic techniques.