Simultaneous Determination of 23 Carcinogenic Dyes in Toothpaste and Mouthwash by High Performance Liquid Chromatography

KeyWord:high performance liquid chromatography  carcinogenic dye  toothpaste  mouthwash

Abstract:

      A high performance liquid chromatographic(HPLC) method with innovative sample pretreatment was developed for the simultaneous determination of 23 carcinogenic dyes in toothpaste and mouthwash.The mouthwash sample was directly dissolved and diluted by ethanol.After mixed by vortex with quartz sand,the toothpaste sample was vacuum dried at 75 ¡æ,then ultrasonically extracted with ethanol at 50 ¡æ for 30 min.The separation of 23 target analytes was performed on a ZORBAX Eclipse XDB-Phenyl column(150 mm¡Á4ª±6 mm¡Á5 ¦Ìm) by gradient elution with 2ª±5 mmol/L tetrabutylammonium phosphate(pH 7ª±5) and methanol-acetonitrile(50¡Ã50,by volume) as mobile phases.The detection wavelengths for diode array detector(DAD) were 400 nm,500 nm and 600 nm,respectively.Quantitative analysis was carried out by external standard method.Results showed that the chromatographic separation for 23 carcinogenic compounds was achieved within 32 minutes.There were good linear relationships for 23 target analytes in the corresponding concentration ranges with correlation coefficients(r2) not less than 0ª±999 1.The detection limits(LOD) and quantitation limits(LOQ) were in the ranges of 0ª±06-0ª±66 mg/L and 0ª±18-1ª±98 mg/L,respectively.The average recoveries for 23 carcinogenic dyes in negative toothpaste and mouthwash at three spiked levels were in the ranges of 91ª±2%-104%and 92ª±0%-103%,with their relative standard deviations(RSD,n=6) of 2ª±5%-5ª±8%and 2ª±3%-5ª±5%,respectively.239 toothpaste and 88 mouthwash samples were detected by this method,and basic violet 3 was detected in a toothpaste sample.With the advantages of high sensitivity,good precision and satisfactory accuracy,the method is suitable for the quantitative analysis of 23 carcinogenic dyes in all kinds of toothpaste and mouthwash,and provides a good strategy reference for the quality and safety monitoring of toothpaste and mouthwash.