Determination of L-Glutathione Reduced
At present, there are many methods for the determination of L-Glutathione Reduced, such as: colorimetry, iodometry, fluorescence method, enzyme cycle method, capillary electrophoresis, etc., which also includes the most commonly used high-performance liquid chromatography. These methods have their own advantages, but also have their own shortcomings. In recent years, with the continuous deepening of L-Glutathione Reduced research, the research of L-Glutathione Reduced determination method has great significance for it.
The principle of iodometry is to use the reducibility of L-Glutathione Reduced, which can react with potassium iodate, and when the reaction of L-Glutathione Reduced to be measured is complete, the remaining potassium iodate can be oxidized with potassium iodide It is iodine, and the end point of the reaction is determined by the color method that starch turns blue when it meets iodine. Determine the corresponding L-Glutathione Reduced concentration according to the amount of potassium iodate consumed. The main method used is that the consumption of L-Glutathione Reduced is proportional to the consumption of potassium iodate. A standard curve can be drawn and then titrated with potassium iodate. The source of L-Glutathione Reduced, the amount of potassium iodate consumed by titration on the standard curve and the corresponding L-Glutathione Reduced concentration, so as to determine the mass fraction of L-Glutathione Reduced. This method of operation is simple, the requirements of the instrument used are not very high, and the measurement time is relatively short, but this method has a shortcoming, the sensitivity of the measurement is not very high, and a preliminary measurement can be done for products with higher content. .
The principle of fluorescence method is to use L-Glutathione Reduced and other substances to form a fluorescent system to determine the content of L-Glutathione Reduced. Usually used is the complexation of o-phthalaldehyde, which can produce a fluorescent complex with L-Glutathione Reduced under alkaline conditions. The fluorescence emitted by the fluorescent complex under ultraviolet light is used to combine the fluorescence signal with L-Glutathione Reduced. A standard curve is drawn for the concentration of the sample, and the concentration of L-Glutathione Reduced can be determined based on the fluorescence signal and the standard curve displayed by the ultraviolet light, so that the content of L-Glutathione Reduced can be determined. This method is highly sensitive and the determination speed is very fast, but the interference of this method is large, so that the error of the determination of L-Glutathione Reduced content is relatively large.
- Alloxan Method
The alloxan method mainly uses L-Glutathione Reduced to react with alloxan under experimental conditions, and the resulting compound has the highest absorption peak at 305nm, using the highest absorption of the resulting compound Peak to determine the content of L-Glutathione Reduced. In the alloxan method, the color reaction exhibited by the reaction did not significantly decrease after a period of time, indicating that this method is stable in color development. The most important thing is that the relative error of this method can be controlled in a very low range, which further proves that the accuracy and precision of this method are relatively high, and other substances do not interfere with the determination.
The principle of colorimetry is to use a color reagent to develop color at a specific detection wavelength to determine the content of L-Glutathione Reduced. The color reagent used for L-Glutathione Reduced is a mixture of copper sulfate test solution and new copper reagent, and the detection wavelength is 456 nm. It also uses the color signal and the concentration of L-Glutathione Reduced to draw a standard curve. Within the range, the concentration of L-Glutathione Reduced can be determined. The most obvious advantage of the colorimetric method is the low cost of the experiment, the simple experiment, the short operation time, and the fast analysis speed.
- Enzyme cycle
The principle of the enzyme cycle method is to use redox reaction, reduced L-Glutathione Reduced is oxidized by dimercapto-2-nitro benzoic acid to generate oxidized L-Glutathione Reduced and relatively stable 5-mercapto-2-nitro benzoic acid. Using oxidized L-Glutathione Reduced and reduced nicotinamide adenine dinucleotide phosphate, reduced L-Glutathione Reduced is finally generated. The rate of 5-mercapto-2-nitrobenzoic acid produced in this reaction is proportional to the total L-Glutathione Reduced content in the sample, so that the L-Glutathione Reduced content can be determined. The L-Glutathione Reduced sample determined by this method is easy to prepare, and the detection speed is fast, which can save time