Determination of mimosine and 3,4-dihydroxypyridine in milk and plasma of goats

R. Puchala, J. J. Davis and T. Sahlu

A simple method for determination of mimosine and 3,4-dihydroxypyridine(3,4-DHP)in plasma and milk was developed. Milk and plasma, with tyrosine as internal standard, were deproteinized using 9% trichloracetic acid and extracted with diethyl ether. Metabolites were separated by isocratic high-performance liquid chromatography, with 0.02 M ortho phosphoric acid (pH 2.5) at 0.5 ml/min and a Hypersil ODS microbore column. Mimosine, 3,4-DHP and tyrosine were detected at 275 nm. The recovery of the mimosine added to the plasma samples was 101.6±2.3% and 103.3±1.0% for milk samples. 3,4-DHP recovery for plasma samples was 101.2±0.9% and for milk samples 100.8±1.4%. The analyses yielded relative standard deviation of 2.65 and 2.82%, respectively.