Gas chromatographic-mass spectrometric screening for organic acidemias using dried urine filter paper: determination of #alpha#-ketoacids

摘要

There are several organic acid disorders that require information on #alpha#-ketoacids, such as maple syrup urine disease or #alpha#-ketoadipic acidemia. The recovery, stability and diagnostic availability of #alpha#-ketoacids in dried urine filter paper analyzed by GC-MS with oxime-trimethylsilyl derivatization was studied for organic acidemia screening. The recovery of all nine types of #alpha#-ketoacids tested, but for phenylpyruvate, 2-ketoadipate, and p-OH-phenylpyruvate, from filter paper samples was acceptable. The stability of pyruvate, branched-chain #alpha#-ketonacids, #alpha#-ketoadipate and #alpha#-ketoglutarate was stable for at least 28 days, although some #alpha#-ketoacids such as succinylacetone were unstable. It indicated it was difficult to diagnose only tyrosinemia type 1 among nine specimens from organic acidenia patients tested. The method could be applied to global organic acidemia screening.