A new method for the determination of plasma phenylalanine.
Two hundred microlitres of plasma is deproteinised, and chloride is removed with TCA/silver iodate. After centrifugation of the phenylalanine in the protein-free extract is oxidised to benzaldehyde with buffered sodium metaperiodate. The benzaldehyde is extracted into iso-octane, and the absorbance of the organic layer is measured at 240 nm. The method gives good agreement with a paper chromatographic method at normal and elevated levels of phenylalanine. All the reagents are stable indefinitely, and a single determination can be completed in 15 minutes.
D001547:Benzaldehydes / Q000032:analysis; D006801:Humans; D008722:Methods; D010504:Periodic Acid; D010649:Phenylalanine / Q000097:blood*; D013056:Spectrophotometry, Ultraviolet
D001547:Benzaldehydes; D010504:Periodic Acid; D010649:Phenylalanine