Simultaneous Determination of 11 Benzophenone-Type Ultraviolet Absorbents in Textiles by HPLC

The shredded textile sample (0.500 0 g) was extracted ultrasonically at 60 ℃ for 30 min with 30 mL of methanol. After cooling to room temperature,the supernatant was taken and filtered with 0.45 μ m organic filter membrane. HPLC was applied to the simultaneous determination of 11 benzophenone-type ultraviolet absorbents in the filtrate. xBridge shield RP C₁₈ chromatographic column (250 mm×4.6 mm, 5 μm) was used as separation column, and mixtures of 0.1% (φ, the same below) formic acid solution and methanol-isopropanol solution (volume ratio of 7∶3) containing 0.1% formic acid with different mixing ratios were used as mobile phase in the gradient elution. Detection at 280 nm was adopted in the determination. Linear relationships between values of peak area and mass concentration of the 11 benzophenone-type ultraviolet absorbents were kept in the same range of 0.5-20.0 mg·L^-1, with detection limits (3S/N) in the range of 3-9 mg·kg^-1 and lower limits of determination (10S/N) in the range of 9-27 mg·kg^-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 87.6%-107%, with RSDs (n=6) of determined values in the range of 1.9%-8.3%. The method was used to analyze samples of 33 batches of anti-ultraviolet fabric. Except that 4-hydroxybenzophenone was not detected in all fabrics, other benzophenone-type ultraviolet absorbents were found in these samples. The highest detection rate of 2-hydroxy-4-methoxybenzophenone was 58%, and the mass fraction of 2-hydroxy-4-methoxybenzophenone was in the range of 42-261 mg·kg^-1.