title: Rapid automated quantitation of isoleucine, leucine, tyrosine and phenylalanine from dried blood filter paper specimens.
abstract: Isothermal and isocratic HPLC chromatography for rapid quantitation of isoleucine and leucine (merged peak), tyrosine and phenylalanine from a single dried blood filter paper specimen (1/8" dot blot) is described. The net chromatography time of the relevant peaks is less than 3 min. The results can be used to screen for PKU, MSUD, and tyrosinemia in one single assay. The advantage for early determination of PKU by simultaneous quantitation of both phenylalanine and tyrosine with the determination of their ratio is discussed. Using a dual column system this procedure might be suitable for large-scale newborn screening.
authors.affiliation: Human Genetics Program, Tulane University School of Medicine, New Orleans, LA 70112.
authors.forename: Y
authors.initials: Y
authors.lastname: Qu
authors.forename: J B
authors.initials: JB
authors.lastname: Miller
authors.forename: R H
authors.initials: RH
authors.lastname: Slocum
authors.forename: E
authors.initials: E
authors.lastname: Shapira
mesh_terms: D000592:Amino Acid Metabolism, Inborn Errors / Q000097:blood / Q000175:diagnosis; D001322:Autoanalysis / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007231:Infant, Newborn; D007532:Isoleucine / Q000097:blood*; D007930:Leucine / Q000097:blood*; D008375:Maple Syrup Urine Disease / Q000097:blood / Q000175:diagnosis; D015997:Neonatal Screening; D010209:Paper; D010649:Phenylalanine / Q000097:blood*; D010661:Phenylketonurias / Q000097:blood / Q000175:diagnosis; D014443:Tyrosine / Q000097:blood*
chemical_list: D007532:Isoleucine; D014443:Tyrosine; D010649:Phenylalanine; D007930:Leucine