Solid surface room temperature phosphorimetry analysis of reserpine in pharmaceutical formulations

A simple, rapid and sensitive method for reserpine analysis has been developed based on solid surface room temperature phosphorimetry. Phosphorescence emission was induced by the reserpine hydrolysis reaction in basic medium. Chromatography paper previously treated for background reduction was employed as a solid substrate. Four heavy atom salts and sodium dodecyl sulfate were tested for maximum signal intensity. A calibration curve with a linear dynamic range of three orders of magnitude (10⁻⁷-10⁻⁴M) was obtained. A 1.9 ng limit of detection was estimated and recoveries of 98.7 and 100.3% were obtained in two dosage forms with different pharmaceutical matrices.