A simultaneous determination method for 16 synthetic colorants in hotpot condiment was developed
by high performance liquid chromatography. The samples were successively extracted with 2 mol/L carbamide
solution containing 5% ammonia (dissolved in methanol) and methanol–acetone solution, and
then the target analytes could be divided into two groups named as lipid-soluble and water-soluble colorants
by ethyl acetate-cyclohexane with liquid–liquid extraction. The lipid-soluble and water-soluble
colorants were purified by gel permeation chromatography and solid phase extraction column packed
with polyamide resin, respectively. The obtained two eluates were combined, concentrated, and separated
by C18 column and determined by diode array detector. Good linear relationships between peak
areas and the concentrations of the synthetic colorants were obtained in the range of 0.01–50.0 mg/L
with correlation coefficients above 0.999 (n = 10). The limits of detection and quantitation were 1–3 and
10 g/kg for 16 synthetic colorants, respectively. The average recoveries at the spiked levels of 5, 10, 20
and 50 g/kg were in the range of 63.2–97.1% with relative standard deviations (n = 6) around 1.5–10.6%.
This method is sensitive and reliable, and can be used to simultaneously determine 8 lipid-soluble and 8
water-soluble colorants in hotpot condiment.