Development and characterization of a FIA system for selective assay of L-ascorbic acid in food samples.
An amperometric detector and an enzymatic reaction were combined for the measurement of L-ascorbic acid. The enzyme cell (containing immobilized ascorbate oxidase) was connected to a flow injection analyzer (FIA) system with a glassy carbon electrode as an amperometric detector. During optimization and measurements two sample injectors were used, one before and one after the enzyme cell, thus eliminating the background interferences. Subtraction of the signal area given in the presence of enzyme from the one given in the absence of enzyme was applied for measuring analyte concentrations and calibration at 400 mV. Analysis capacity of system is 25 samples/hour. The relative standard deviation (RSD) was below 5% (5 times repeated, 400 μmol/L conc.), linearity up to 400 μmol/L, limit of detection (LOD) 5 μmol/L, fitting of calibration curve in 25-400 μmol/L range was R (2) = 0.99.
Vig
Attila
A
EGERFOOD Regional Research Centre, College of Károly Eszterházy, Leányka u. 6, Eger, 3300, Hungary. v.attila81@freemail.hu
Igloi
Attila
A
Adanyi
Nora
N
Gyemant
Gyongyi
G
Csutoras
Csaba
C
Kiss
Attila
A
D001204:Ascorbate Oxidase / Q000737:chemistry; D001205:Ascorbic Acid / Q000032:analysis*; D002384:Catalysis; D004563:Electrochemistry; D004800:Enzymes, Immobilized / Q000737:chemistry; D017022:Flow Injection Analysis / Q000295:instrumentation*; D005504:Food Analysis / Q000295:instrumentation*; D057230:Limit of Detection; D015203:Reproducibility of Results
D004800:Enzymes, Immobilized; D001204:Ascorbate Oxidase; D001205:Ascorbic Acid