Simultaneous Determination of 17 Hydroxybenzoate Compounds in Medical Dressing Category Medical Device Products by High Performance Liquid Chromatography

After adding the mixed solution of methanol and acetonitrile at volume ratio of 8∶2 into samples of medical dressing category medical device products, vortex mixing, ultrasonic extraction, and centrifugal separation were performed. The supernatant was passed through a 0.22 μm filter membrane, and the filtrate was introduced into the high performance liquid chromatograph. Hydroxybenzoate compounds (PBs) were separated by gradient elution with mixed solutions of acetonitrile and 0.12% (volume fraction) phosphoric acid solution at different volume ratios on the ShimNex CS C₁₈ column, and quantified by the external standard method. It was shown that linear relationships between values of mass concentration and peak area of 17 PBs were kept in the range of 1-50 mg·L⁻¹, with detection limits (3S/N) in the range of 5-18 mg·kg⁻¹. Test for recovery was made according to the standard addition method, giving recoveries in the range of 97.6%-108%, and RSDs (n=6) of the determined values ranged from 0.30% to 4.4%. This method was used to screen 10 batches of actual samples with different matrices, and the detection rate of PBs was 40%. Methyl p-hydroxybenzoate was detected in 1 batch of samples, and ethyl p-hydroxybenzoate and propyl p-hydroxybenzoate were detected in 3 batches of samples.