Determination of Boric acid in Cosmetics by Ion Exclusion Chromatography

The sample of cosmetics was dissolved with water,and the content of boric acid in sample solution was determined by ion exclusion chromatography.The IonPac ICE-Borate(250 mm×9 mm,7.5 μm) exclusion chromatographic column was used for separation,and a mixture of 3 mmol·L-1 methanesulfonic acid (MSA) and 60 mmol·L-1 mannitol was used as eluent.Non-inhibitory conductivity detection was adopted in the determination.Linearity range of boric acid was found in the range of 0.12 to 20.0 mg·L-1,with detection limit (3s) of the method of 0.85 mg·kg-1.The proposed method was applied to the determination of boric acid in cosmetics,giving values of recovery found by standard addition method in the range of 93.2% to 103.5% and RSD (n=6) ranged from 2.4% to 5.9%.