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在中性或弱酸性溶液中,Sb~V可以定量地被Cr~(2+)还原成金属狀态,但在此情况下,砷离子并不会被还原成元素。因此三价及五价砷的存在,对銻的測定并不发生干扰。过濾銻被还原后的沉淀,并以氯化銨溶液(2%)洗滌2～3次,沉淀以20毫升硫酸(1:4)溶解,然后滴加K_2Cr_2O_7溶液,經5～10分鐘,过量的K_2Cr_2O_7先以硫酸亞铁銨溶液滴定至淡黄色,然后加隣苯氨基苯甲酸指示剂6滴,继續滴定至色变。用二苯胺作指示剂时,溶液内需加磷酸。如銻的含量約1毫克时,最好用0.2NK_2Cr_2O_7溶液滴定;銻的含量更少,則需用0.1NK_2Cr_2O_7溶液。本法的灵敏度在100毫升溶液中可測出0.05毫克的銻。原文:2,201～203(1957)
In neutral or weakly acidic solutions, Sb ~ V can be quantitatively reduced by Cr ~ (2+) to the metal state, but in this case, arsenic ions are not reduced to the elements. Therefore, the presence of trivalent and pentavalent arsenic does not interfere with the determination of antimony. The precipitated antimony is filtered and washed with ammonium chloride solution (2%) 2 to 3 times. The precipitate is dissolved with 20 ml of sulfuric acid (1: 4), and then K 2 Cr 2 O 7 solution is added dropwise for 5 to 10 minutes. K_2Cr_2O_7 first ammonium ferrous sulfate solution titration to pale yellow, then add o-aniline benzoic acid indicator 6 drops, continue titration to color change. With diphenylamine as an indicator, add phosphoric acid in the solution. Such as antimony content of about 1 mg, the best solution with 0.2NK_2Cr_2O_7 titration; less antimony content, you need 0.1NK_2Cr_2O_7 solution. The sensitivity of this method can be measured in 100 ml of solution 0.05 mg of antimony. Original: 2,201 ~ 203 (1957)