POLY(VINYL ALCOHOL) AS SOLID SUBSTRATE MATERIAL FOR ROOM-TEMPERATURE PHOSPHORIMETRY

A mixture of poly(vinyl alcohol) (PVA) and a small amount (5%) of cell ulose (CLL) was pressed under similar to 280 kg/cm(2) to form a disk o f 1 mm thickness, and the prepared disk was used as a solid substrate for room-temperature phosphorescence (RTP). The addition of CLL was to reduce the fragility of the disk and enhance the permeability of samp le solutions into the disk surface. The sample solution spotted PVA-CL L solid substrates were dried in a microwave oven conveniently. The ef ficiency of PVA-CLL solid substrates was monitored by RTP intensity of p-aminobenzoic acid (PABA) spotted on them, and the results showed th at the RTP signal of PABA was largely enhanced as compared to that on the conventional paper solid substrates. Another prominent feature of the PVA-CLL solid substrate is that the RTP signal can be observed suf ficiently even without a dry gas flush during the RTP measurement, whi le a dry gas hush is essential for the conventional substrates. A cali bration curve for PABA was linear from 7.3 to 1200 pmol/spot. The resu lts for the RTP measurements of chlorpromazine hydrochloride and tetra caine hydrochloride were also reported. The limits of detection of PAB A and the other two drugs were 0.03, 0.16 and 1.26 ng, respectively.