This study demonstrates a 2D-LC method for determination of Sudan dyes I, II, III, and IV in three different curry pastes using an UltiMate 3000 Dual Gradient HPLC system. The sample is partially separated in the first dimension, then the portions of the chromatogram containing peaks of interest are sent to the second dimension where they are further resolved. The second dimension uses a column with selectivity different from that used in the first dimension. The total runtime is 25 min. The offline sample preparation step is only a simple sample extraction using acetonitrile followed by filtration. The two-dimensional method precludes the need for more rigorous offline SPE sample preparation. This results in significant time and labor savings, and thereby reduces the cost per analysis.
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