Determination of gibberellic acid by capillary electrophoresis

Abstract

Micellar electrokinetic chromatography (MEKC) was developed as a method for quantitative determination of gibberellic acid (GA₃) in fermentation broth, using disodium tetraborate (Na₂B₄O₇) as a buffer at pH 9.2 and sodium dodecylsulfate (SDS) as a micellar phase. Baseline resolution of GA₃ from other compounds in the fermentation broth was achieved using the following MEKC conditions: 25 mM Na₂B₄O₇, 100 mM SDS and separation voltage of+30 kV. The amount ofGA₃ in the fermentation broths determined by MEKC was found to be in good agreement with that by high performance liquid chromatography. The MEKC method was also applied for quantitative determination of GA₃ in commercial products. Advantages of this method include fast analysis, high accuracy and precision and no sample preparation except for filtration and dilution.