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Indirect fluorescence of aliphatic carboxylic acids in nonaqueous capillary electrophoresis using merocyanine 540
Author(s) -
Chiu TaiChia,
Huang MingFeng,
Huang ChihChing,
Hsieh MingMu,
Chang HuanTsung
Publication year - 2002
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/1522-2683(200202)23:3<449::aid-elps449>3.0.co;2-p
Subject(s) - chemistry , capillary electrophoresis , aqueous solution , acetonitrile , chromatography , ascorbic acid , carboxylic acid , quantum yield , solvent , fluorescence , resolution (logic) , analytical chemistry (journal) , organic chemistry , physics , food science , quantum mechanics , artificial intelligence , computer science
A method for the analysis of aliphatic carboxylic acids (ACAs) in nonaqueous capillary electrophoresis (NACE) in conjunction with indirect laser‐induced fluorescence (ILIF) using merocyanine 540 (MC 540) is described. Performing the analysis in organic solvent is advantageous when using MC 540, because of its greater quantum yield in aprotic solvent. To achieve a high dynamic reserve (DR) and optimize resolution, we have tested a number of aqueous mixtures containing alcohols and acetonitrile (ACN). The optimum buffer for the analysis of C2‐C18 ACAs, in terms of sensitivity, resolution, and speed, is an aqueous mixture of 40% ACN, 30% ethanol, and 1 m M Tris at apparent pH 7.4 (adjusted with ascorbic acid). Under this condition, the DR is greater than 1000, thereby the limits of detection for acids are in the range of sub‐ν M to ν M . Linear plots show that the dynamic ranges for the analysis of ACAs are at least two decades in concentration, with regression coefficients all greater than 0.98. The relative standard deviations of the migration times and peak heights for all ACAs are less than 2.0%. Furthermore, this simple and cost‐effective method has been applied to the analysis of marine lipid concentrate, with the concentrations of 1.67 ± 0.03 and 4.50 plusmn; 0.05 m M ( n = 5) for C14 and C16 acids, respectively, in a tablet of marine lipid concentrate sample.