RESUMO
Objetive To explore the method for determination of titanium dioxide in sunscreen cosmetics by spectrophotometry.Methods The cosmetic sample was undergone ashing treatment at 500 ℃ for dry 4 h,then was added with 2 g ammonium sulfate and 8ml concentrated sulfuric acid,for complete digestion.Titanium dioxide was determined by spectrophotometry with diantipyryl-methane as the chromogenic agent.Results The linear range of the standard curve was 0.1-6.0 ?g/ml.The detectable minimum concentration was 0.1%.Linear correlation coefficient was 0.999 8.The average recovery rates were 97.2%-98.5%.RSDs were 0.62%-1.85%(n=6).Conclusion This method is simple,rapid,accurate and suitable for the determination of titanium dioxide in sunscreen cosmetics.
RESUMO
Objective To develope a method for determination of hydroxide in depilatory cosmetics and to provide the basis for the establishment of national standard method for determination of hydroxide in depilatory cosmetics. Methods Potentiometric titration method was used in this assay. Results This method revealed good precision(RSD