Quantitative measurement method for theanine

Abstract

The invention discloses a quantitative measurement method for theanine. The method comprises the following steps of: leaching a tea sample by using water, spotting a theanine standard solution, a blank solution and a tea leaching liquor on rectangular filter paper respectively, taking an ethanol-water-ninhydrin mixed solution as a developing agent, performing vertical chromatography, drying, eluting by using an ethanol solution, and measuring the content of the theanine by comparing color at the wavelength of 570nm by using a spectrophotometer. The tea sample is leached by water and the ethanol solution is used for development, so that the stimulation of toxic substances to operators and pollution of the toxic substances on environment are avoided; ninhydrin is mixed into the developing agent, so that operating steps are reduced, and the quantification of development reaction and uniform color spots are ensured; the blank solution and the theanine working solution are spotted and subjected to chromatography, and a standard curve is made, so that a control, a standard substance and a sample are subjected to the same treatment, errors are reduced, and the measurement accuracy is improved; and all measurement steps are simple, the types of related medicines are a few, and the method is economic and environment-friendly.

Description

technical field [0001] The invention belongs to the field of biochemistry, in particular to a method for measuring the content of theanine with a spectrophotometer after chromatography on plant sample paper. [0002] Background technique [0003] L-theanine, also known as glutamyl ethylamine, English name L-Theanine, Cas number: 3081-61-6, molecular formula: C 7 h 14 N 2 o 3 , is an amide compound, white or off-white powder, melting point 214-215 degrees, easily soluble in water, with caramel aroma and fresh taste similar to monosodium glutamate. [0004] L-theanine only exists in some plants of the genus Camellia and a kind of fungus in nature, accounting for between 1% and 2% of the dry weight of tea leaves, accounting for more than 50% of the total free amino acids, and is the main substance that constitutes the flavor of tea One of them is also widely used in the food industry. Modern medicine has confirmed that theanine has many health care effects on the human bo...

AI Technical Summary

Problems solved by technology

The ether used in this method is extremely volatile, is an anesthetic, and is a dangerous product. Ethyl acetate, n-butanol, glacial acetic acid, and ammonia water are all irritating and low-toxic drugs to the human body; the circular filter paper has a limited spread distance due to its diameter. It is relatively short and requires continuous secondary spectrum expansion to separate amino acids, resulting in a waste of drugs and no time advantage; the color reaction occurs after the paper chromatography is sprayed with ninhydrin, and the color spots are uneven due to the lack of control of the amount of the color developer : The standard curve is prepared, and the standard sample is not subjected to paper chromatography steps, which is different from the measurement sample processing, resulting in measurement errors: There is no special spotting for the blank, and it is cut at will, which causes the measurement to be inaccurate

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