The analysis of biological fluids for the antenatal and perinatal diagnosis of metabolic disease

Gas chromatography/mass spectrometry profiling methods for the identification and accurate quantitation of organic acid metabolites in urine, amniotic fluid and serum have been developed. These methods allow quantitation of organic acids in body fluid samples with a lower limit of detection of 0.3 yg/ml and a precision of 0.1 yg/ml, with less than 4% variation between duplicate samples. An isotope dilution method was developed to validate the profiling method for methylmalonic acid.