Fluoranthene

TPS concentrations were measured according to the method reported by Yoshida et al. (21 (link)), using 5-mm cubic tissue blocks of 124 samples from 47 cases excised from each area assessed as strong, weak or no during the surgery. To the resected brain tumor tissue per 100 mg, 5 mL of a mixture of HEPES buffer solution and CH₃OH (1:9) was added, then the tissue was homogenized while cooling in ice for 1 min, and the supernatant was used as a measurement sample. The TPS and the internal standard, fluoranthene (Wako Pure Chemical Industries Ltd., Osaka, Japan), in each measurement sample were separated based on the principle of reverse phase liquid chromatography (Inertsil® ODS-2, GL Science Inc., Tokyo, Japan), and detected by a fluorescence detector. Based on each peak area obtained, the peak area ratio relative to fluoranthene was calculated and used the values as TPS concentrations. For patients in whom the concentration was measured at multiple sites in each area assessed as strong, weak or no fluorescence, the mean concentration was used for the evaluation.

Hexane, acetone, ethanol, and sodium sulfate (Wako Pure Chemicals Industries, Ltd., Japan) used for the analyses were of residual agricultural chemical grade. Water purified by a Millipore Direct-Q^® 3UV water purification system was washed with Hexane twice prior to use. Authentic PAH standards (phenanthrene [Phe], anthracene [Anth], fluoranthene [Flu], pyrene [Pyr], chrysene [Chry], benzo[b]fluoranthene [[b]flu], benzo[a]pyrene [[a]pyr], and perylene [Pery]), deuterated PAHs, and p-terphenyl-d₁₄ were purchased from Wako Pure Chemicals Industries, Ltd. (Japan). Deuterated surrogate standards were used to compensate for PAH losses during analysis.