DETERMINATION OF SULFURIC-ACID AND OXALIC -ACID IN DRINK BY MEANS OF HPLC BIOSENSOR COUPLING

In the present work a new rapid HPLC-method is described for measuring sulphite in beer and other foodstuffs. In this case an enzyme reactor is coupled with a HPLC-system for postcolumn derivatisation, and the created products are detected amperometrically. It is a very sensitive method (detection limit 0.02 mg/l SO2), which gives accurate and repr oducible results also in the sub-ppm range (<10 ppm). The detector res ponse is linear up to 4 mg/l SO2. A comparison with a distillative met hod shows good correlation. In a further application, the determinatio n of oxalic acid in beer, the high accuracy of the method was shown by means of the comparison with an ion-chromatographic method.