ROOM-TEMPERATURE PHOSPHORESCENCE CHARACTERISTICS OF INDOLE-3-PROPIONIC ACID, DL-INDOLE-3-LACTIC ACID, AND INDOLE-3-GLYCOLIC ACID ON LOW-BACKGROUND PAPER SUBSTRATE
Room temperature phosphorescence characteristics of indole-3-propionic acid, DL-indole-3-lactic acid, and indole-3-glycolic acid were studied on a low-background paper substrate. The influence of potassium iodide, thallium (I) nitrate, silver (I) nitrate, and lead (II) acetate on the intensities of the analyte signals was evaluated. The effects of sodium dodecyl sulfate and pH conditions were studied as well. The analytical figures of merit were obtained for each compound under experimental conditions for maximum phosphorescence emission. Calibration curves with linear dynamic ranges extended between two and three orders of magnitude and limits of detection at the nanogram level were estimated. (C) 1995 Academic Press, Inc.