Spectral properties of quinine sulfate in PVA films for front-face format emission measurements.

The luminescence properties of quinine sulfate (QS) embedded in poly(vinyl alcohol) (PVA) film have been studied in detail. Fluorescence excitation and emission spectra were measured using a front-face configuration, and the corresponding intensities were tabulated. A fluorescence quantum yield of 0.51 was determined for QS-doped PVA, using QS dissolved in 1N H2SO4. Both excitation and emission anisotropy measurements indicated effective immobilization of QS molecules within the polymer matrix. The fluorescence lifetime of QS-doped PVA was measured using a picosecond-pulsed 375 nm laser diode and analyzed with both exponential and Lorentzian distribution models. The broad lifetime distribution suggests a complex interaction between QS molecules and the polymer matrix. The QS-doped PVA films are well suited for measurements involving solid materials and front-face geometries.