摘要：Tha micro quantitative determination of Ca in serum with glyoxal bis (2-hydroxyanil) (GBHA) was investigeted. Of many metal ions which are present with Ca in serum, Na, Mg and Pb did not form complex with GBHA. Zinc and Cu are masked by adding 10% NaCN solution to the reaction mixture, Fe and Mn are also masked with 10% triethanolamine. n-Butanol was the most preferable solvent for the extraction of the colored chelate component of Ca with GBHA, because of high sensitivity and no interference with yellow colored serum bilirubin. Methanol and sodium hydroxide-sodium borate buffer were used for the solvent for the preparation of the GBHA reagent solution and for color development, respectively. The stability of the colored chelate in the solution was good. The colorimetric determination of Ca in serum gave good agreements in the recovery of added Ca to serum and in comparison with earlier Clark-Collip's method.
