New diagnostic techniques for the detection of organic acidemias.
We describe an improved procedure for the extraction of organic acids which is equally suitable for urine, plasma and amniotic fluid and gives similar high recoveries for a wide variety of organic acids, without interferences from phosphate, sulfate, or urea. Internal standards are added, the oxoacids are converted to the pentafluorobenzyloximes; the sample is concentrated, acidified, chromatographed on a small column of silicic acid, and the effluent neutralized and dried. After forming the trimethylsilyl derivatives, gas chromatography is done on a 0.53 mm X 30 m low-polarity bonded-phase fused silica capillary column. For gas chromatographic-mass spectrometric quantification, the peak areas at the m/z of a characteristic fragment ion for each acid relative to the peak areas of ions of the internal standards are related to standard curves.
Department of Pediatrics, University of California, San Diego, La Jolla.
L
L
Sweetman
G
G
Hoffmann
S
S
Aramaki
D000328:Adult; D002264:Carboxylic Acids / Q000097:blood*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008661:Metabolism, Inborn Errors / Q000097:blood*
D002264:Carboxylic Acids