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运用酪氨酸与４－氨基安替吡啉的显色反应测定食品中酪氨酸的含量。微波加热水解３０ｓ后，可在不分离其它氨基酸的条件下直接测定酪氨酸。向５ｍＬ的水解液中依次加入５ｍＬ５．０×１０－２ｍｏｌ／Ｌ４－氨基安替比林，２．５ｍＬＮＨ４ＯＨ－ＮＨ４Ｃｌ缓冲溶液（ｐＨ９．４０），２．５ｍＬ０．１ｍｏｌ／Ｌ高碘酸钠溶液，用二次水定容于５０ｍＬ。显色２５ｍｉｎ后，以空白作参比，在４８０ｎｍ波长下测定吸光度值。浓度在６．０×１０－６～１．８×１０－４ｍｏｌ／Ｌ的酪氨酸符合比耳定律。表观摩尔吸光系数为３．０３×１０３Ｌ／ｍｏｌ．ｃｍ。对含量为３．１９％酪氨酸样品多次重复测量，相对标准偏差为０．４２％。考察了其它氨基酸对测定的干扰。该方法测定的回收率为１００．４％～１０２．０％。同时推测了显色反应的机理。
Determination of tyrosine in foods by chromogenic reaction of tyrosine with 4-aminoantipyrine. Tyrosine can be measured directly without separating other amino acids after microwave heating and hydrolysis for 30s. To 5 mL of the hydrolyzate, 5 mL of 5.0 × 10 -2 mol / L 4-aminoantipyrine, 2.5 mL of NH 4 OH-NH 4 Cl buffer solution (pH 9.40), 2.5 mL of 0.1 mol / L sodium periodate solution, With secondary water volume in 50mL. After 25 min of color development, the blank was used as a reference, and the absorbance value was measured at a wavelength of 480 nm. The tyrosine concentration of 6.0 × 10-6 ~ 1.8 × 10-4mol / L conforms to Beer’s law. The apparent molar absorptivity is 3.03 × 103L / mol. cm. Repeated measurements of 3.19% tyrosine sample with a relative standard deviation of 0.42%. Other amino acids were investigated for interference with the assay. The recovery of this method was 100.4% ~ 102.0%. At the same time speculated that the color reaction mechanism.