【摘要】 稀土元素是我国丰产元素之一,矿区和冶炼厂有废水排出,要治理废水,需要测试废水中稀土的含量,目前未见报导.我们研究了CPAmN测试工业废水中铈组稀土的含量,以后再研究钇组稀土的测试方法.废水中含有许多其他离子,其中钙、钪、钛、钍和锆对测定有严重干扰,为了消除干扰,用PMBP萃取分离后再行测定. 过去用苯或氯仿做PMBP的溶剂,因其毒性大,有害于人体健康,我们用石油醚代替苯或氯仿,在给定条件下,等体积、一次萃取入有机相,再用等体积pH1.9甲酸溶液反萃取,除钐的回收率为84%外,其余铈组稀土均在90%以上.比耳定律的范围为0～12微克铈.铈的摩尔吸光系数为8.5×10~4升/摩尔·厘米;Sandell灵敏度为0.00165微克铈/厘米~2.以河水和工业废水为例,铈的回收率在95.8～100.3%之间,对测定结果感到满意.更多还原

【Abstract】 The choice of petroleum ether instead of benzene or chloroform used as a solvent for l-phenyl-3-methyl-4-benzoyl-5-pyrazolone to extract cerium sub-group rare earth elements from their foreign elements is investigated.In petroleum ether, the keto-form of PMBP converts advantageously into enol-form which reacts with rare earth elements to form chelates.The recovering method for petroleum ether is simple.Petroleum ether is less poisonous than benzene or chloroform.After PMBP-petroleum ether extraction at pH5.5 and back extraction with formic acid at pH1.9,the percentage of recovery of any cerium sub-group rare earth element is above 90, except that of samarium is 84.The molar absorptivity of cerium at 666 nm is found to be 8.5×10⁴ 1·mole^-1·cm^-1,the sensitivity （according to Sandell） is 0.00165μg Ce/cm².Beer’s law is obeyed for 0～12 μg of cerium in 25 ml of solution at 666 nm.Sampling from river water and industrial waste water, the recovery of cerium is between 95.8～100.3%, and the results of determinations are satisfactory.更多还原