| A hybrid high performance liquid chromatographic method was developed for the determination of alkyphenol ethoxylates（NPnEO and OPnEO，n=0-30）in detergent products and cosmetics.Different types of samples were extracted by ultrasonic assisted extraction using a mixture of acetonitrile-water（8∶2）.The chromatographic separation was conducted with a reverse phase column of C18（Poroshell 120 EC-C18,75 mm×4.6 mm,2.7 μm）coupled with a HILIC-Silia column（Atlantis HILIC Slica,250 mm×4.6 mm,5 μm）by gradient elution using acetonitrile-10 mmol/L ammonium acetate as mobile phase.The detection was performed with a fluorescence detector（FLD）.A quantitative model was established based on fluorescence molar absorption coefficients of NPnEO and OPnEO.With the quantification of the hybrid standard solution of NPnEO and OPnEO,the fluorescence molar absorption coefficients of NPnEO and OPnEO were determined.The average molecular weight of NPnEO and OPnEO in real samples were measured,and the concentrations of the analytes were calculated with the fluorescence molar absorption coefficients.With this method,the average recoveries for APEOS ranged from 99.0% to 105.7% with relative standard deviations no more than 12.5%,and the limit of quantitation were both 40.0 mg/kg. |