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提出了用PMBP-萃淋树脂柱色谱萃取、甲酸洗脱分离稀土,在KCl介质中用偶氮胂Ⅲ显色剂光度法测定磷肥中稀土总量的方法。对三种磷肥试样测定的统计结果表明,本方法标准偏差(SD)小于1.6%、相对标准偏差(RSD)小于7%。与PMBP-苯溶剂萃取光度法测定结果相比,相对误差小于3%。本法用于磷肥中稀土总量测定,具有结果可靠、无环境污染、易于推广的优点。 相似文献
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测定微量钼的分光光度法很多,但都是用于含量在10~(-3)%以上的样品,对于复杂矿物中含量在10~(-4)~10~(-5)%范围内的分光光度法尚未见有报导.本文研究根据文献[2]的显色反应和条件采用结晶紫分光光度法测定磷矿石中微量 相似文献
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According to the appearing of isosbestic point in the absorption spectra of Ho/Y-Tribromoarsenazo(TBA)systems,the complexation reaction is considered to be M nL=ML_n.A method has been proposed basedon it for calculating the mole fraction of free complexing agent in the solutions from spectral data.and two linearregression formula have been introduced to determine the composition,the molar absorptivity,the conditionalstability constant of the complex and the concentration of the complexing agent.This method has been used in Ho-TBA and Y-TBA systems.Ho~(3 )and Y~(3 )react with TBA and form 1:2 complexes in HCl-NaAc buffer solution at pH 3.80.Their molar absorptivities determined are 1.03×10~8 and1.10×10~8 cm~2·mol~(-1),and the conditional stability constants(logβ_2)are 11.37 and 11.15 respectively.Afterconsidering the pH effect in TBA complexing,their stability constants(log β_2~(ahs))are 43.23 and 43.01.respectively.The new method is adaptable to such systems where the accurate concentration of the complexingagent can not be known conveniently. 相似文献
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