Use of a diode array detector in investigation of neonatal organic aciduria.

We investigated the use of a diode array detector in conjunction with isocratic cation-exchange liquid chromatography for detection of organic acids in urine. The spectra and retention times of abnormal peaks found on chromatography of urine from patients with methylmalonic aciduria, maple syrup urine disease, and lactic aciduria were recorded and compared with those obtained for group of pure organic acids. Our results show that diode array detection helps considerably in tentatively identifying peaks appearing on an abnormal chromatogram while awaiting confirmation by mass spectrometry.