Analytical Sciences


Abstract − Analytical Sciences, 19(8), 1173 (2003).

Determination of Proteins Using thep-Acetylchlorophosphonazo-Barium(II) Complex as aSpectroprobe
Shulin ZHAO,  DianmeiLIU, and Shuting LI
Department of Chemistry and ChemicalEngineering, Guangxi Normal University, Guilin 541004, China
A novel spectrophotometric method has beendeveloped for the determination of proteins using thep-acetychlorophosphonazo (CPA-pA)-barium(II) complex as aspectroprobe. In the pH range of 2.0 - 2.8, the absorbance of theCPA-pA-barium(II) complex at 649 nm is greatly decreased by protein.The absorbance decrease is in proportion to the concentration of protein inthe range of 0 - 20 mg/L. The apparent molar absorptivities are 1.56 x106, 1.70 x 106 and 6.04 x 105 Lmol-1 cm-1 for bovine serum albumin (BSA), humanserum albumin (HAS) and ovalbumin (OVA), respectively. The method isreproducible and simple, and has been used to determine total protein inhuman sera. The results are in agreement with those obtained by thepyrocatechol violet (PV)-Mo(VI) method, with relative standard deviationsof 2.5 - 3.5% (n = 6).