薄層クロマトグラフィーとデジタルカメラを用いる環境試料中の多環芳香族炭化水素の簡易定量法の開発

摘要

本研究は，環境試料中の多環芳香族炭化水素（PAHs）の安価で簡易な定量法の開発を目的とし，薄層クロマトグラフィー（TLC）とデジタルカメラ（DC）を用いた手法（TLC-DC法）の構築を行った．ベンゾ［a］ビレンを含むPAHs混合標準溶液（0.01～0.5ppm）10μLを，カフェイン修飾したTLCプレート上で展開後，励起光を照射し，RAHsからの蛍光をデジタルカメラで撮影した．得られたデータから発光スポットの切り出し，強度の積算により作成した各PAHの検量線は，良好な直線を示した．検出限界は6.1～8.8ng mL~(-1)（61～81 pg spot~(-1)）と見積もられた．また環境試料（底質）の前処理液を同様のTLCプレート上で展開し，標準添加法を用いて定量したところ，ガスクロマトグラフィーー質量分析法（GC-MS）で得られた結果と良く一致した．本研究より，TLC-DC法で，底質試料中のベンゾ［a］ビレン,フルオランテン，ベンゾ［b］フルオランテン，ペリレンを，GC-MSと同程度の高感度でありながら，GC-MSより安価で簡易に定量可能であることが示された．%A simple, sensitive and rapid quantitative method for polycyclic aromatic hydrocarbons (PAHs) in sediment samples was developed by using thin-layer chromatography (TLC) and a digital camera (DC). This method (TLC-DC method) has three-parts: 1. Separation of different types of PAHs on a TLC plate impregnated with a 6 % (w/v) caffeine solution; 2. Excitation of each PAH on the TLC plate by irradiation of a UV lamp and recording of the fluorescence image from each PAH by DC; 3. Analysis of the image data and making calibration curves of PAHs on a personal computer. Anthracene (Anth), fluoranthene (Flu), pyrene (Pyr), benzo[b]fluoranthene ([b]flu), benzo[a]pyrene ([a]pyr), and perylene (Pery) were selected as target compounds. The calibration curves of each PAH obtained in the concentration of 0.01 to 0.3 ppm showed high linearity (R = 0.977-0.999). The detection limits for four PAHs (Flu, [b]flu, [a]pyr and Pery) were from 6.8 - 8.8 ng mL~(-1) (61 - 88 pg per spot), which were almost at the same levels as those by the GC-MS method. Moreover, sediment samples collected at Yoro tidal flat were pretreated. Their PAH concentrations were measured by TLC-DC and GC-MS methods. The PAH concentrations of the sediment samples were 2 - 8 μg kg-dry~(-1) by the standard addition TLC-DC method, and the values obtained were in good agreement with the values obtained by the internal standard GC-MS method. These results concluded that the TLC-DC method is useful for the quantification of four kinds of PAHs, benzo[a]pyrene, fluoranthene, benzo[b]fluoranthene, and perylene in sediment samples.