Kb. Male et al., AN IMPROVED FIA BIOSENSOR FOR THE DETERMINATION OF ASPARTAME IN DIETARY FOOD-PRODUCTS, Applied biochemistry and biotechnology, 38(3), 1993, pp. 189-201
A flow injection analysis (FIA) biosensor system was developed for the
determination of the artificial sweetener aspartame (L-aspartyl-L-phe
nylalanine methyl ester). The system consisted of an enzyme column of
pronase immobilized on activated arylamine glass beads and a L-amino a
cid oxidase electrode connected in series. The dipeptide bond of aspar
tame was cleaved by immobilized pronase to release phenylalanine, whic
h was in turn monitored by the enzyme electrode that used L-amino acid
oxidase immobilized on a preactivated nylon membrane in combination w
ith an amperometric electrode (platinum vs silver/silver chloride, 700
mV). The response of the FIA biosensor was linear up to 1 mM aspartam
e with a lower detection limit of 25 muM and had good reproducibility
(rsd 0.3%). The FIA biosensor was stable for at least 30 h of continuo
us use at T(r). Each assay takes 4 min giving a sample throughput of 1
5 h-1. When applied to aspartame in dietary food products the results
obtained agreed well with those reported by the product manufacturers.