A semi automated procedure for the measurement of 3-methoxy-4 hydroxy mandelic acid.

A semi automated procedure for the determination of 3-methoxy-4-hydroxy-mandelic acid (HMMA) in urine has been evaluated. This procedure offers advantages in simplicity, speed and precision over existing manual techniques which utilize spectrophotometric fluorimetric and gas liquid chromatographic methods. The urine is extracted with ethyl acetate from a highly acidic sample, purified by extraction into acetate buffer and the diazo colour reaction developed. All stages of the procedure are carried out using the Brown and semi-automatic extractor equipped with partition tube. The within and between assay coefficient of variation obtained on pooled freeze-dried urine samples was 6.7% and 7.7% respectively.