【摘要】 本文报告用BPHA的氯仿溶液萃取水相中的硫氰酸钛,硫氰酸根能提高钛的萃取率与加深顏色(增加反应的灵敏度)。为便于随后比色,萃取时酸浓度应为12N硫酸或8N盐酸。此外,尚找出BPHA及硫氰酸銨的适宜用量、測定钛适宜范围及其他离子的影响。此法可应用于大量鋁中微克量钛的比色测定。钛,BPHA与硫氰酸根三者所形成的絡合物能溶于氯仿。經用推广的Job法測定其組成比为 Ti:BPHA:SCN=1:2:1。更多还原

【Abstract】 A chloroform or iso-amyl alcohol solution of N-benzoyl-N-phenylhydroxylamine （BPHA） can be used for the extraction of titanium from strong acid solution. The titanium-BPHA complex in the organic solvents mentioned is yellow and good for the separation of milligram quantities of titanium. It has been found in our laboratory that the addition of ammonium thiocyanate to acid titanium solution would increase both the percentage extraction of titanium and the colour intensity of its complex. Based upon this reaction, a procedure with solvent extraction and spectrophotometric determination of microgram quantities of titanium has been devised.Factors that might affect the percentage extraction and spectrophotometric determination of titanium have been studied. It has been found for extraction of 10 ml of aqueous titanium （20μg） solution with 5 ml of BPHA-CHCl₃ solution, the addition of 0.2gm of ammonium thiocyanate to aqueous phase is adequate. The aqueous solution should be 10—16 N in sulphuric acid or 7—9 N in hydrochloric acid. For up to 20μg of titanium, the use of 10 mg of BPHA is sufficient and the colour intensities produced obey Beer’s law. The colour intensity of titanium-BPHA-thiocyanate complex does not change within two hours, thereafter it increases slightly. The use of carbon tetrachloride or benzene does not produce a colour as intense as chloroform for the same amount of titanium. The absorption spectrum of the titanium complex has been recorded. Therefrom, 420 mμ has been selected for recording the extinction of the titanium complex.The effect of diverse ions has been studied. One mg of cobalt （Ⅱ）, iron （Ⅲ） and lanthanum （Ⅲ） does not interfere. The tolerable amount of antimony （Ⅲ）, bismuth （Ⅲ）, nickel （Ⅱ）, tin （Ⅳ） and zirconium （Ⅳ） is 100μg. Copper （Ⅱ） causes low results and should be masked with thiourea. Vanadium （Ⅴ）, molybdenum （Ⅵ） and tungsten （Ⅵ） may be present up to two or three times the amount of titanium in sample. Tartaric, oxalic and phosphoric acids may be present up to 100mg. Fluoride ions interfete, while large amount of aluminum （0.1 gm） does not, therefore the method is suitable for the determination of traces of titanium （3—20μg） in aluminum.With extended Job’s method of continuous variation, the ratio of titanium, BPHA and thiocyanate in the complex has been found to be 1:2:1. And the probable formula of the complex may be更多还原