ICP-AES Determination of Boric Acid and Borate in Cosmetics

The sample of cosmetics was treated by micro-wave digestion, and the content of B (in form of boric acid or borate) in the sample solution was determined by ICP-AES. Yttrium was chosen as internal standard, and spectral line with wavelength of 249.678 nm was selected as analytical line for the determination of B. Linear relationship between values of emission intensity and mass concentration of B was obtained in the range within 1.0 mg·L-1, with detection limit (3s) of 0.002 mg·L-1. The proposed method was applied to the analysis of several kinds of cosmetic samples, giving values of recovery and RSD′s (n=10) in ranges of 95.2%-100% and 2.4%-3.8% respectively.