A flow injection spectrophotometric method is described for the determination of NAD+ based on the production of NADH using immobilized alcohol dehydrogenase (ADH) isolated from Baker's yeast. The absorbance was monitored at 340 nm. The limit of detection (2 x standard deviation of the blank) was 0.01 mM with sample throughput 60 h-I. The calibration graph was linear in the range 0.2 - 1.0 mM, with relative standard deviation (n = 3) in the range 0.7 - 1.2%. Phenolic resin was used as a support for ADH immobilization and the  enzyme activity was maintained for three months.


M YAQOOB ,L RISHI ,A NABI ,M MASOOM YASINZAI ,