Total Bilirubin (TBIL) is the sum of direct bilirubin and indirect bilirubin.Serum total bilirubin is an important test item in liver and courage.It is important to accurately reflect the degree of jaundice, it is important for clinical diagnosis of hidden jaundice.In the presence of a surfactant, total bilirubin can be oxidized by sodium nitrite to form chloride.The content of the total biliary uretarin can be calculated by detecting a wavelength change of 450 nm.