ABSTRACT
Objective: To establish an HPLC-DAD method for the determination of 9 artificial synthetic colorants used in shells of hard capsule, with traditional Chinese materia medica Yigan Jiedu capsule used as a case study. Methods: Nine water-sol uble colorants, tartrazine, sunset yellow, amaranth, ponceau 4R, erythrosine, brilliant blue, quinoline yellow, azorubine and allura red, were determined by the HPLC-DAD method. The column was Agilent Zorbax Extend C 18(250 mm×4.6 mm, 5 μm), the mobile phase was the methanol-20 mmol/L ammonium acetate solution in gradient elution, the flow rate was 1.0 ml/min, the column tempera ture was 35℃, and the injected sample solution volume was 5 μl. Results: The chromatographic peaks of all colorants were well sep arated and showed a good linearity in the range of 8.74-960 ng(r=0.9997~1.0000), and the recovery of nine colorants was 90.42%-104.07%. Total 1-5 kinds of colorants were detected in 26 batches of samples, among which, more than 3 kinds of colorants were de tected in 13 batches of samples and 15 batches of samples contained more than 0.5% of total colorant content. Conclusion: The use of colorant in capsule shells needs to be standardized, and the present method might be used for the quality control of hard capsule shells used in the drugs and health products.