UHPLC Determination of Naringin and Denatonium Benzoate in Children's Finger Paint Pads

The sample of children's finger paint pad was extracted ultrasonically for 20 min with a mixture of methanol and 0.02 mol·L^-1 KH₂PO₄ solution (volume ratio, 3:7). After cooling to room temperature,the solution was centrifugated for 15 min at the speed of 16 000 r·min^-1. The supernatant was taken and filtered on 0.22 μm filtering membrane. UHPLC was applied to the determination of naringin and denatonium benzoate in the filtrate. C₁₈ chromatographic column was used as separation column with mixtures of acetonitrile and 0.02 mol·L^-1 KH₂PO₄ solution (pH 4.3) with different mixing ratios as mobile phase in the gradient elution, and diode array detector was adopted for determination. Linear relationships between values of peak area and mass concentration of naringin and denatonium benzoate were kept in the same range of 0.1-5.0 mg·L^-1, with detection limits (3S/N) of 0.75, 1.15 mg·kg^-1 respectively. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 73.5%-104%, with RSDs (n=6) of determined values in the range of 4.2%-6.6%.