1990 年 6 巻 4 号 p. 589-592
Photoacoustic spectroscopy by the rear-surface detection method was proposed for an aluminum-foil thin-layer chromatography (TLC) plate. The aluminum-foil TLC plate was attached to a photoacoustic cell (15mm id.; chamber volume, ca. 0.7ml). The surface of the TLC plate was illuminated by a chopped laser-beam (30Hz; beam size 0.75 mmφ). The photoacoustic signal of the aluminum-foil TLC plate was detected by an electret condenser microphone located at the other end of the cell. The photoacoustic signal of the sample on the TLC plate was seen as a signal superposed on a background signal of the aluminum foil. Background signals caused by light absorption at the surface of aluminum foils were measured for foils 17, 40, 110μm thick. A 40μm-thick aluminum foil showed the largest signal intensity. The amount of cobalt-PAN (1-(2-pyridylazo)-2-naphthol) chelate on a TLC plate was determined by the proposed method. A linear relationship between the amount of cobalt-PAN and the signal intensity was obtained within the range 20-300ng. The detection limit of cobalt-PAN was about 5ng. The reproducibility of measurements for 150ng cobalt-PAN on seven different TLC plates was 0.246 (RSD).
