Determination of other s Adenosyl Nonoxynol 9 Factory methionine: take the goods, add water to make each 1 ml contains 10 mg of solution, according to the thin layer chromatography (TLC) test, drain the solution above 5 mu l, points on the silica G thin layer plate, n-butyl alcohol - glacial acetic acid and water (4:1:5) as developing agent, unfolds, dry, dry in 90 ℃ for 10 minutes, spray with ninhydrin acetone solution (0.5-100), heating at 90 ℃ for 10 minutes, immediately review, should only show a purple spots.
Dry weight loss: take the goods, 3 hours at 105 ℃ dry, loss of weight reduction shall not be over 0.2%. On ignition residue may not be over 0.1%. Iron to take the goods of 1.0 g, inspection in accordance with the law, with the standard control fluid is made of iron solution 1.5 ml, shall not be deeper (0.0015%). Take the goods 0.50 g of heavy metals, 23 ml water dissolves, add acetate buffer (PH3.5) 2 ml, inspection in accordance with the law, containing heavy metals shall not be ten over one million. Take the goods 2.0 g arsenic salt, 23 ml water dissolves, add 5 ml of hydrochloric acid, inspection in accordance with the law, shall comply with regulations (0.0001%).
Pyrogen determination: take the goods, and made Theobromine Powder each 1 ml contains 20 mg of sodium chloride injection solution, inspection in accordance with the law and dose per 1 kg weight on rabbit injected 10 ml, should comply with the rules (for injection).
The method name: methionine API, the determination of methionine, potentiometric titration method
Application: apply the methods using titration method to determine methionine, sense of methionine content API. The method is suitable for methionine API.
Method principle: test samples with anhydrous formic acid and glacial acetic acid dissolves, and potentiometric titration with perchloric acid titration fluid, and use the result of the titration blank test correction, according to the titrant usage, calculate the content of methionine.
Methionine, as one of the alpha s Adenosyl Heme Iron Polypeptide methionine sulfur. Is a kind of composition, protein ovalbumin and casein in the lot, natural is L - type. Is one of the necessary s Adenosyl methionine, L type D is effective. Or remove methyl mercaptan and ammonia, directly and indirectly by homocysteine into alpha keto acid. Methionine biosynthesis from O - acetyl with serine, sulfide, or generated by the inverse way cysteine homocysteine (at this point only appeared in the chain of spore mold), and then to the homocysteine generated by the transfer of methyl. These methyl by (1) N - onium compound betaine (for example), 2 S - onium compounds (such as sulfur generation betaine) directly transferred, are produced by (3) active new C1 unit, etc. Furthermore active methionine itself, also by decomposition into homocysteine, creatine, N - methyl niacin, choline, such as methyl histidine methyl donor.