ABSTRACT
Objective To study the determination of chromium in human hair by spectrophotometry using starch as color agent. Methods The total chromium(Cr)in human hair was oxidized by (NH4?雪2S2O3 into Cr6+,which could oxidize KI to form I-3 in acid medium. I-3 reacted with starch to form a blue colored complex,which revealed the maximum absorption peak at 590 nm. Results The contents of Cr in human hair were 8.46-29.56 ?g/g.The lowest detection limit and linear range were 0.02 and 0.02-1.0 ?g/ml respectively.The coefficient of variation and standard material-added recovery rates were 3.3% and 94.8%-104.5% respectively. Conclusion This methods was rapid,accurate and convenient for the determination of chromium in human hair.
ABSTRACT
Objective To study acute toxicity of nanometer titanium dioxide to the liver and kidney of mice. Methods 20 KM mice (22-26 g) were randomly divided into two groups, the control group and the experimental group, TiO2 (20-30 nm) suspension (single dose of 5 g/kg body weight) was given to mice by a single oral gavage, the mice in the control group were given the physiologicalsaline. 14 days after the treatment, the mice were sacrificed and the serum were collected to evaluate the levels of ALT(alanine amino transferase), AST(aspartate aminotransferase), ALP(alkaline phosphatase), UA(uric acid), Cr(creatinine),BUN(blood urea nitrogen), CK(creatine kinase), LDH(lactate-dehydrogenase), ?-HBDH(alpha-hydroxybutyrate dehydrogenase), TBIL(total bilirubin levels). The tissues of the liver and kidney were excised and were embedded in paraffin blocks, hematoxylin-eosin (HE) staining for further histopathological diagnosis. Results The serum ALT, ALT/AST, BUN, LDH and ?-HBDH of the TiO2 group were statistically higher than those in the control group (P