【摘要】 本文提出一萃取分离和测定微克量钪与钍的快速方法。用5,7-二氯-8-羟基喹啉氯仿溶液从 pH 3.2—3.4的水溶液中萃取钍,此时钪留于水层。于有机相中加二甲酚橙乙醇溶液显色,在540毫微米处测钍的光密度。继用六次甲基四胺调整水层至 pH 5—5.5,萃取钪与显色同上,在530毫微米处测钪的光密度。此法可用于3—15微克钪和10—100微克钍的分离和测定。文中尚有用二甲酚橙测定钪和钍的试验条件。更多还原

【Abstract】 This paper describes a rapid method for the separation and determination of microgram amounts of scandium and thorium.5,7-Dichloro-8-quinolinol in chloroform is used to extract thorium from aqueous solution of pH 3.2—3.4,from which no scandium isextracted.Xylenol Orange ethanolic solution is added directly to the organic layer,afterwashing once with water,and the absorbance is measured at 540 mμ.Then the aqueouslayer containing scandium is adjusted to pH 5—3.5 with urotropin and extract again withdichloroquinolinol in chloroform solution.The scandium in organic layer is also deter-mined directly by adding Xylenol Orange ethanolic solution and measuring the absor-bance at 530mμ.The method is good for 3—15μg of scandium and 10—100μg ofthorium.Iron(Ⅲ)is extracted together with thorium and thus separating from scan-dium.Aluminum shall not develop a colour in the organic layer used at room tempera-ture.Though a small amount of thorium is extracted into the organic layer from aqueoussolutions at or greater than pH 6,the main portion of it does not remain in aqueoussolution,but forms a film at the interface.The phenomenon may be ascribed to thehydrolysis of thorium,with the formation of insoluble basic salts.The percentage extraction of scandium,together with that of thorium,is given in Fig.1(in the Chinese text).Scandium begins to get into organic layer after pH 3.4 and canbe quantitatively extracted from aqueous solution of pH 5 to 8.5 with 0.007 M dichloro-quinolinol in chloroform and thorium,pH 3.2 to 4.5.Therefore pH 3.2 to 3.4 is selectedfor their separation.Although the pH range is narrow,but its control offer no difficultywith acetic acid and ammonium acetate buffer.One ml of 0.1 percent Xylenol Orange ethanolic solution is sufficient for 10μg ofscandium,and 4—5 ml of the same reagent,for 40 μg of thorium to develop the colour.The optical density,after addition of Xylenol Orange,is ready for measurement.Thecolour intensity of scandium is stable over a 3-hour period,while that of thorium,onehour.By plotting optical density vs.amount of scandium(0—15μg)or thorium(0—60μg),straight lines through the origin can be obtained.And scandium line pos-sesses a greater slope.更多还原