利用Berthelot颜色法测定发酵液中铵离子的干扰排除

在利用Berthelot反应测定微生物发酵中铵离子浓度时,培养液中的亚硫酸钠严重干扰了测定结果。预先加入适量的次氯酸钠溶液处理样品能有效地排除这一干扰。对次氯酸钠的加入量、处理时间和待测样品的pH进行优化,结果表明:当次氯酸钠与亚硫酸钠的摩尔比为2∶1、处理时间>1 m in、样品处理前调pH<9.0时,测得发酵液中铵离子浓度,经离子色谱法对照测试验证.最大相对误差为2.3%,达到了理想的效果。

Interference Removal in Ammonium Measurement of Fermentation Broth by Berthelot Color Reaction

Sodium sulfite seriously interfered ammonium measurement in fermentation broth by Berthelot color reaction method.Pretreatment of samples by adding proper amount of sodium hypochloride was found effective to remove the interference.The adding amount of sodium hypochloride,pretreatment time and sample pH were investigated.It was confirmed by ion chromatography analysis that the ammonium concentration of the fermentation broth sample containing sodium sulfite,including some microorganism cells,could be determined satisfactorily by the Berthelot color reaction method modified.