Determination Of Methionine Content In Feedstuff by Potentiometric Titration

Methionine is an important essential amino acid for animals. Methionine hydroxy analogues can be converted into methionine in animal bodies and exert their nutritional effects. In addition, it can also function as a component of several important enzymes (or as a cofactor) in animal bodies. Used as a rumen protein source for ruminants and an acidifier for piglet diets, it can inhibit bacteria, reduce heat stress, and decrease nitrogen excretion, protecting the environment. In addition, methionine is an important amino acid in poultry feed, which can effectively improve egg production rate. We use potentiometric titration to measure the content of basic copper chloride in feed additives, which is more accurate and faster.

Instrument configuration

Instrument: GT30 automatic potentiometric titrator Electrode: ORP electrode

Experimental reagents

0.1mol/L Sodium Thiosulfate Standard Titration Solution

Analysis method

Add excess potassium iodide to the sample and titrate the excess iodine with a standard solution of sodium thiosulfate.

Reference resources:

GB/T 17810-2009 Feed Grade DL Methionine

Calculation formula:

X: the content of methionine in the sample, measured in%;

M:the mass of methionine expressed in grams per mole (g/mol) , which is equivalent to 1mL of sodium thiosulfate standard solution;

C: the actual measured concentration of sodium thiosulfate standard titration solution in moles per liter (mol/L);

V1: the numerical value of the volume of standard sodium thiosulfate titration solution consumed by titrating the sample, in milliliters (mL);

V0 : the value of the volume of sodium thiosulfate standard titration solution consumed by blank titration, in milliliters (mL);

M: Sample quality, measured in grams (g).