This paper describes a method for the determination of PAHs in black, green and decaffeinated tea infusion samples. The method is based on the solid phase extraction of the PAHs using Sep-Pak vac tC-18 cartridges. The PAHs are then eluted from the cartridges with dichloromethane. Quantification and detection are carried out by HPLC with a fluorimetric detector using a program of excitation and emission wavelength pairs. Recoveries at concentration levels in the range 190-1790 ng l-1 were higher than 65% for all PAHs except dibenz[a,h]anthracene, for which it was around 54%. The mean content of PAHs was in the range 28.7-112 ng l-1 in the tea infusions, with relative standard deviations between 2 and 18% (n = 4).

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A new method for PAHs determination in toasted bread samples is proposed. The method is based on supercritical-fluid extraction, using CO 2 and acetonitrile as modifier. The extracted PAHs were collected in 1 mL acetonitrile. Quantitation was carried out by HPLC with fluorimetric detection. A Hypersil Green PAH column, acetonitrile-water gradient mobile phase, and a program of 11 excitation and emission wavelength pairs for fluorimetric detection were used. Recoveries at concentration levels in the range 0.15-3.56 µg/kg bread were close to 100% for all PAHs except fluoranthene, chrysene, and benzo[ghi]perylene. Some PAHs were detected in these samples within the range 0.323-9.40 µg/kg toasted bread; the relative standard deviations were in the range 2 -12% (n=4).

A rapid method for the determination of PAHs in soil samples based on their extraction with methylene chloride by sonication and subsequent separation by HPLC with fluorimetric detection is proposed. A Hypersil Green PAH column was used with a gradient of acetonitrile/water as the mobile phase, together with a program of nine excitation and emission wavelength pairs. Recoveries were in the range 70-98%, except for acenaphthene and naphthalene, at concentration levels 1.08-442 microg/kg with relative standard deviations in the range 2-15% (n = 4). Total PAHs found in soil samples were in the range 15-282 microg/kg. The results were compared with those obtained by applying the 3540 EPA method for two samples.

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