Enzymatic determination of zinc in vegetables using apocarbonic anhydrase.

摘要

A new enzymatic method has been developed to determine trace amounts of Zn2+ in vegetables (peas, carrots, cabbage, lettuce, potatoes, aubergine, tomatoes, spinach, onions and sweet corn). The basis of the method is that apocarbonic anhydrase regains its activity in proportion to the concentration of Zn2+ present in the solution. Bovine carbonic anhydrase was purified from erythrocyte haemolysate by affinity chromatography and the bound Zn2+ removed by dialysis of purified enzyme against a solution of pyridine-2, 6-dicarboxylic acid. Pure (100%) apoenzyme was obtained. The concentration of Zn2+ in vegetable samples was determined using the enzymatic method and by atomic absorption spectroscopy. Determinations made using the two methods were not significantly different one from another.