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A very fast, selective kinetic method for the determination of propyl gallate is proposed. The analytical parameter used for this purpose is the initial rate of the luminescence reaction between propyl gallate and terbium(Ir1) in the presence of sodium dodecyl sulfate, and is calculated from the slope of a kinetic plot of the luminescence signal as a function of time. The luminescence signal arises from an intramolecular energy transfer between excited propyl gallate and terbium(m), which is followed by the lanthanide emission. Kinetic data can be obtained within only 0.2 s, which entails using the stopped-flow mixing technique but facilitates automation. The calibration graph is linear over the range 0.08-1.0 pg ml-1 propyl gallate and the detection limit is 0.02 pg ml-1. The relative standard deviation is close to 2%. The proposed method was applied to the determination of propyl gallate in various edible and cosmetic oil samples with a mean recovery of 99.1 YO.

The stopped-flow mixing technique was applied for the first time to micelle-stabilized room-temperature phosphorimetry by measuring the fast appearance of the phosphorescent signal yielded by carbaryl in the presence of sodium dodecyl sulfate and thalious ion. The slope and amplitude of the kinetic curves obtained are directly proportional to the analyte concentration, which allows one to develop very simple, fast, automatic methods for the phosphorimetric determination of dissolved carbaryl without the need for solid substrates. Kinetic and equilibrium data can be obtained within only 2-3 s with a greater precision than that provided by solid-surface room-temperature phosphorimetry. The calibration graphs obtained for the proposed kinetic and equilibrium stopped-flow method were linear over the range 0.030-2.0 and 0.050-3.0 Mg mL"1 carbaryl, respectively, and the detection limits achieved were 0.010 and 0.014 Mg mL*1, respectively, i.e., lower than those provided by solid substrates.Kinetic methodology is widely used in phosphorimetry to determine the lifetime of the excited triplet state, a characteristic property of molecules and their environment. The phosphorescence lifetime is a major parameter since compounds having very similar spectral features may have greatly different triplet lifetimes. However, kinetic methodology has not been used for analytical purposes by measuring the rate of formation of a phosphorescent system. Similar to other analytical techniques, this can be accomplished by obtaining a kinetic curve reflecting the variation of phosphorescence with time and using its slope as an analytical parameter. Such