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Rapid analysis of azo‐dyes in food by microchip electrophoresis with electrochemical detection
Author(s) -
Dossi Nicolò,
Piccin Evandro,
Bontempelli Gino,
Carrilho Emanuel,
Wang Joseph
Publication year - 2007
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200700208
Subject(s) - amaranth , repeatability , detection limit , analyte , chromatography , electrokinetic phenomena , electrophoresis , chemistry , capillary electrophoresis , analytical chemistry (journal) , materials science , food science
A method based on microchip electrophoresis with electrochemical (EC) detection has been developed for the simultaneous determination of Yellow AB, Red 2G, Sunset Yellow, New Coccine, and Amaranth which are azo‐dyes frequently added to foodstuffs. Factors affecting both separation and detection processes were examined and optimized, with best performance achieved by using a 10 mM phosphate buffer (pH 11) as BGE solution and applying a voltage of 2500 V both in the separation and in the electrokinetic injection (duration 4 s). Under these optimal conditions, the target dye analytes could be separated and detected within 300 s by applying a detection potential of −1.0 V ( vs. Ag/AgCl) to the glassy carbon (GC) working electrode. The recorded peaks were characterized by a good repeatability (RSD = 1.8–3.2%), high sensitivity, and a wide linear range. Detection limits of 3.8, 3.4, 3.6, 9.1, 15.1 μM were obtained for Yellow AB, Red 2G, Sunset Yellow, New Coccine, and Amaranth, respectively. Fast, sensitive, and selective response makes the new microchip protocol very attractive for the quantitative analysis of commercial soft drinks and candies.