Determination of Sulfonated Water-Soluble Azo Dyes in Foods by SPE Coupled with HPTLC-DAD

摘要

The purpose of the present work is to demonstrate an application of high-performance thin-layer chromatography-diode array scanning densitometry (HPTLC-DAD) after solid-phase extraction (SPE) for the identification and quantitative analysis of azo dyes in samples of drinks and drops. To prepare the samples for SPE, diethylamine was added to a final concentration of 0.025 M. For analysis of dyes, the samples were applied to Bakerbond Octadecyl C18 SPE columns. After being loaded with the samples, the C18 SPE columns were eluted with different volumes and concentrations of mixtures (v/v) of methanol-acetate buffer, pH 3.5. The procedure described for the determination of compounds is inexpensive and can be applied to routine analysis of analytes in water-soluble samples of drinks and drops after preliminary cleanup, concentration, and fractionation by SPE. Limits of detection and limits of quatita-tion values were satisfactory, in the range 31.5-119.4 and 95.3-361.8 ng per zone, respectively, for all determined dyes.