[Determination of five kinds of restricted preservatives in cosmetics by HPLC]

In order to detect and monitor preservative component in cosmetic, the method for determination of five kinds of restricted substances benzoic acid, chloroxylenol, o-phenyl phenol and p-chloro-m-cresol chlorhexidine in cosmetics by HPLC was carried out.

10 kinds of commercial cosmetics as test samples, using methanol as the extracting solution, saturated sodium chloride solution as precipitant, and Agilent Eclipse XDB-C18 (250 mm x 4.6 mm, 5 microm) as analytical column methanol -0.1 nol/L sodium dihydrogen phosphate solution (pH 3.0) was as mobile phase eluting at a flow rate 1.0 ml/min, the detective wavelength was 285 nm.

The method for determination of chlorhexidine and other four kinds of restricted substances had good linear relationship, the linear correlation coefficients were greater than 0.9990, the limit of detection ( LOD) of 0.8 - 2.2 ng, the average recoveries were between 95.0% -104.0%.

The method is accurate and reliable, and it is a useful supplement for "Hygienic Standard for Cosmetics".