An improved method for measuring blood concentrations of phenylpyruvic acid
Coburn, S.P.; Mahuren, J.D.; Fuller, R.W.
Clinical Chemistry 17(5): 378-381
1971
ISSN/ISBN: 0009-9147 PMID: 5573400 Document Number: 33855
A mixture of 4 ml serum or plasma, 4 g NaCl, 0.2 ml HCl and 10 ml ethyl acetate was shaken for 3 min and centrifuged at 1200 g for 10 min. The acetate layer, 8 ml, and 0 5 ml phosphate buffer, pH 8 1, was shaken and centrifuged. The phosphate layer, 150 mu l, was added to each of 2 tubes containing 0.2 ml phosphate buffer or 0.2 ml borate buffer, pH 8.1. Absorbance was measured at 298 nm 1 h after mixing and the difference between the 2 mixtures was due to phenylpyruvic acid.