Abstract: Usually, there is a broad excitation and emission band in room temperature phosphorescence spectra.When a multicomponent mixture is analysed, spectral overlap occurs frequently.Therefore, it is difficult to determine the constituents in mixture.The room temperature phosphorescence characteristics of p-terphenyl(p-TP) and m-terphenyl(m-TP) are extremely similar.The spectral interference between them is very serious.To eliminate this interference, we have set up the second derivative solid substrate room temperature phosphorimetry for the simultaneous determination of trace p-TPand m-TP.The proposed method is simple, rapid and reproducible.Its major advantage is that the mutual interference of p-TPand m-TPcan be eliminated effectively without any preliminary separation.The excitation wavelength of the sample spot was at 288 nm, m-TPwas measured at 448 nm with a positive signal and 460 nm with a negative signal.The calibration curve is linear over the range of 0.46 to 46 ng.The absolute LODis 0.11 ng per spot.The presence of p-TPdoes not interfere with the determination.p-TPwas measured at 526 nm with a positive signal and 548 nm with a negative signal, with a linear range of 0.46 to 46 ng and the absolute LODof 0.07 ng per spot.The presence of m-TPdoes not interfere with the determination.

Key words: Derivative solid substrate room temperature phosphorimetry, Simultaneous determination, p-Terphenyl, m-Terphenyl