PHOTOCHEMILUMINESCENT DETECTION OF ANTIRADICAL ACTIVITY .3. A SIMPLE ASSAY OF ASCORBATE IN BLOOD-PLASMA

A simple procedure to determine the ascorbate in blood plasma was elab orated based on a temporary inhibition of the photo-induced, O-2(-.)-m ediated, chemiluminescence emanating from oxidation of luminol. To rem ove the interferences, mainly from urate, a simple enzyme-free one-ste p method for plasma sample preparation by means of a gel filtration wa s combined with the photochemiluminescent investigation of the eluate. The results of the photochemiluminescent assay of ascorbate coincide well (r = 0.994) with a photometric method with ascorbate oxidase. The mean value of ascorbate in human blood plasma, obtained from 37 healt hy volunteers, was 59.6 +/- 25.8 mu mol/l. Patients with atheroscleros is having a myocardial infarction in their anamnesis displayed signifi cantly lower values: 27.2 +/- 12.8 mu mol/l (n = 32), P < 0.001.