Abstract
A novel enzymatic simultaneous assay of phenylalanine and tyrosine using phenylalanine-and tyrosine-decarboxylases was developed. The two enzymes were absorbed in a small piece of filter paper, dried and placed in a test tube, followed by the addition of sample solution. After the whole quantity of the sample was absorbed into the filter paper, the tube was incubated, then t-butylmethylether containing diethylamine was added to stop the reaction and to extract the reaction products, β-phenylethylamine and tyramine. Fluorescence intensities of β-pheylethylamine and tyramine in the organic phase were then measured at 278 nm and 305 nm of emission with excitation at 255 nm, and 275 nm, respectively.
