White or almost white crystalline powder or colourless crystals
Appearance (JP)
White crystals or crystalline powder
Solubility (USP)
Soluble in water, in warm dilute alcohol and in dilute mineral acids. Insoluble in ether, in absolute alcohol, in benzene and in acetone
Solubility (EP, BP)
Soluble in water, very slightly soluble in ethanol (96%)
Solubility (JP)
It is freely soluble in formic acid and soluble in water and very slightly soluble in ethanol (95%). It dissolves in dilute hydrochloric acid.
pH (USP)
5.60 - 6.10 (1% in water)
pH (EP, BP)
5.50 - 6.50 (2.5% in water)
pH (JP)
5.2 - 6.2 (2.5% in water)
Identification : FTIR (JP)
Matches with the standard pattern
Identification A : FTIR (USP)
Matches with the standard pattern
Identification A : Specific rotation (EP, BP)
+22.5 to +24.0 (c = 2% in HCl R1 at 20 ± 0.5°C, dried substance)
Identification B : FTIR (EP, BP)
Matches with the standard pattern
Identification C: TLC (EP, BP)
The principal spot in the chromatogram obtained with the test solution is similar in position, colour and size to the principal spot in the chromatogram obtained with the reference solution
Identification D (EP, BP)
A dark red colour develops
Appearance of solution (EP, BP)
2.5% solution in water is clear and colourless
Clarity & colour of solution (JP)
Solution of 0.5 gm in 20 mL of 2 mol/L HCl is clear and colourless
Chloride (USP)
<= 0.05%
Chloride (EP, BP)
<= 0.02%
Chloride (JP)
<= 0.021%
Ammonium (EP, BP, JP)
<= 0.02%
Sulfate (USP)
<= 0.03%
Sulfate (EP, BP)
<= 0.03%
Sulfate (JP)
<= 0.028%
Iron (USP)
<= 0.003%
Iron (EP, BP)
<= 0.001%
Sulfated ash (EP, BP)
<= 0.10%
Arsenic (JP)
<= 0.0002%
Related substances : TLC (JP)
The spots other than the principal spot from the sample solution are not more intense than the spot from the standard solution
Related compounds, system suitability : HPLC : resolution (USP, EP, BP)
>= 5.0, the resolution between the methionine and L-methionine sulfoxide peaks
Related compounds : Methionine sulfoxide : HPLC (USP)
<= 0.1%
Related compounds : N-Acetyl-D,L-Methionine : HPLC (USP)
<= 0.20%
Related compounds : Any unspecified impurity : HPLC (USP, EP, BP)
<= 0.10%
Related compounds : Total unspecified impurities : HPLC (USP, EP, BP)
<= 0.3%
Specific rotation (USP)
+22.4° to +24.7° (c = 2% in 6N HCl, at 25°C)
Specific rotation (EP, BP)
+22.5° to +24.0° (c = 2% in HCl R1 at 20 ± 0.5°C, dried substance)
Specific rotation (JP)
+21.0° to +25.0° (c = 2% in 6M HCl at 20°C, dried substance)