Determination of adulteration of malachite green in green pea and some prepared foodstuffs by micellar liquid chromatography.

A simple, fast, and robust micellar LC method was developed for the separation and identification of the nonpermitted color malachite green in green pea and some ready-to-eat foodstuffs. Malachite green (4-[(4-dimethylaminophenyl) phenyl-methyl]-N,N-dimethylaniline) is a hazardous dye that is used to treat fungal and protozoan infections in fish and is a common adulterant (coloring agent) in green pea and other green vegetables because of its green color. In the present work, malachite green was determined in various foodstuffs using a direct injection technique on an RP C18 column with isocratic elution. The optimum mobile phase consisted of 0.15 M sodium dodecyl sulfate (SDS), 6% pentanol buffered at pH 5. Detection was carried out at 620 nm. Malachite green was eluted in 9.2 min without any interference caused by endogenous compounds. Linearities (r > 0.9999), intraday and interday precision (RSD less than 1.00%) in micellar media, and robustness were studied for method validation. LOD and LOQ were 0.10 and 0.25 ppm, respectively. The simplicity of the developed method makes it useful for routine analysis in the area of food QC.