Deng Jian, Xu Jin-sheng, Fan Hua, Yuan Ya-li, Liu Chuan-xiang
College of Chemistry and Chemical Engineering, Nanhua University, Hengyang 421001, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2005 Mar;25(3):436-8.
A new method for direct determination of ammonia in plasmas with indophenol reagent is described. It is shown that using sodium citrate as anticoagulant in phosphate buffer within pH 10.5-11.2, indophenol reagent reacts sensitively with ammonia in the plasmas to form a stable blue compound with a maximum absorption at 630 nm with low interference. The apparent molor absorptivity is 2.48 x 10(4) L x mol(-1) cm(-1) , and the linear range 0-1500 micromol x L(-1) (r = 0.9999) with a detection limit of 1.7 micromol x L(-1). The relative standard deviation is 1.13% (n=11) and the recoveries are in the range of 93.6%-101.6% with an average recovery of 97. 0%. The proposed method has been applied to detect ammonia in the plasmas from 43 healthy persons and 97 patients who suffered from liver diseases with satisfactory results.
本文描述了一种用靛酚试剂直接测定血浆中氨的新方法。结果表明，在pH 10.5 - 11.2的磷酸盐缓冲液中使用柠檬酸钠作为抗凝剂时，靛酚试剂能与血浆中的氨灵敏反应，形成一种稳定的蓝色化合物，在630 nm处有最大吸收，干扰小。表观摩尔吸光系数为2.48×10⁴ L·mol⁻¹·cm⁻¹，线性范围为0 - 1500 μmol·L⁻¹（r = 0.9999），检测限为1.7 μmol·L⁻¹。相对标准偏差为1.13%（n = 11），回收率在93.6% - 101.6%之间，平均回收率为97.0%。该方法已应用于检测43名健康人和97名肝病患者血浆中的氨，结果令人满意。
