Determination of titanium dioxide content in middle and fine cotton varieties by UV spectrophotometry

4,5-Dihydroxy-2,7-naphthalenedisulfonic acid ligands and titanium had color reaction and produced stable complexes,the maximum absorption wavelength of the complexes was 461nm,molar absorption coefficient e=3.17×104L·(mol·cm)-1,titanium concentration showed a good linear relationship,in the range of 0.001~1.0μg·mL-1 with the varieties of cotton fabric were measured in the titanium.In the results,the relative standard deviation(RSD) was 2.91%,the recovery was 94.57%~100.14%.