Sensitizing Effect of Mixed Surfactants on the Colouration of Scandium(Ⅲ)with Phenylfluorone or Its Derivatives

In the presence of mixed micelle of a cationic and a nonionic surfactants,the reaction of scandium(Ⅲ)with phenylfluorone or its derivatives results in a very sensitive colouration:furthermore this chromophoricsystem tolerates the existence of a considerable amount of masking agents,so that many interfering ions can bemasked and its selectivity would be further improved.After studying the optimum conditions and main charac-ters of some similar systems,the system of Sc(Ⅲ)—Orthonitrophenyuorone—CetyltrimethylammoniumBromide(CTMAB)—Triton X-200 is chosen for the spectrophotometric determination of microamount ofscandium.The proposed method shows not only high sensitivity(with a molar absorptivity of 2.12×1~sLmol~(-1)·cm~(-1))and selectivity,but also high tolerance of chromophoric conditions.Beer's law is obeyed over arange of 0～6.0 μg Sc/25ml.If the dual-wavelength method is applied,a much higher molar absorptivity o|"3.04×10~5L·mol~(-1)·cm~(-1)than those of other systems ever reported in the literatures can be attained:more-over.its linear range is extended to 0～8.0 μg Sc/25ml and its reproducibility is also improved.     

Extraction-chromatographic Separation of Microamount Scandium(Ⅲ)with HEH(EHP) Resin and Its Analytical Application

The optimum conditions for the extraction-chromatography by using 2-ethylhexyl-2-ethylhexyl-phosphonate resin to separate scandium(Ⅲ)from large amounts of other metal ions were reported.A me-thod for the separation and determination of microamount of scandium has been developed.This methodgives higher accuracy and reproducibility than solvent extraction with PMBP,especially,for the samplescontaining high content of titanium.Many shortcomings of other methods ever reported can be overcomeby the present method.     

Co-colouration Effects in the Systems of Metal(Ⅱ)-Rare Earth(Ⅲ)-Xanthene Dye and Their Influences on Photometric Determination of Metal Ions

After comparing the influences of each rare earth(Ⅲ),11 species of metal(Ⅱ)and 8 species of acidictriphenylmethane dye on the formation of coloured coordination compound in the system of Metal(Ⅱ)-RE(Ⅲ)-Dye,it was proven that the co-colouration effect can be caused only by the xanthene dyes(XD)con-taining substituting hydroxy.group on the ortho-position of etheric oxygen group.Besides,the radius of met-al(Ⅱ)must not be smaller than a definite limit;otherwise,no co-colouration appears.Furthermore,the acid-ity of medium is another important factor to affect co-colouration,Bromopyrogallol red causesco-colouration of Pb(Ⅱ)-RE(Ⅲ)only,owing to its higher chromophoric acidity;while alizarin violet causesco-colouration of M(Ⅱ)-RE(Ⅲ)(M=Pb,Ca,Sr and Ba),due to its lower chromophoric acidity.The condi-tions causing co-colouration,the regularities of co-colouration and the influences of co-colouration inphotometric determination of metals were discussed.     

2—（2—噻唑偶氮）—5—二乙基氨基酚光度法测定微量铬的研究

本文提出了2－（2－噻唑偶氮）－5－二乙基氨基酚（TADAP）光度法测定微量铬的新方法，探索铬（Ⅲ）的TADAP配合物的配体交换惰性行为和各种表面活性剂的增溶增敏行为，给出了惰性显色配合物的形成条件、组成及其在测定微量铬中的应用。     

Ga(Ⅲ)—o-NPF—F~-—CTMAB四元显色体系及其分析应用的研究

研究了镓(Ⅲ)—邻硝基苯基荧光酮—X—表面活性剂四元显色配合物的形成条件及分析特性,并用于矿石中痕量镓的测定,结果满意。     

混合表面活性剂对钪(Ⅲ)与苯基荧光酮类显色反应的影响及高钛试样中微量钪的测定

比较了混合表面活性剂对钪(Ⅳ)与苯基荧光酮及其几种衍生物的显色反应的影响,证明苯基邻位有含孤对p电子的取代基者,混合表面活性剂并无明显的协同增敏效应,但可使显色条件变宽.提出了用P_(507)树脂萃取色层分离后用水杨基荧光酮(SAF)分光光度测定高钛试样中微量钪的方法,准确度和重现性皆好.     

〈钛(Ⅳ)-5-Br-PADAP——羟胺——氯乙酸〉体系混配络合物及其分析应用(“金属离子——2-吡啶偶氮染料——L”体系多元络合物研究之三)

本文报导了<钛(Ⅳ)——5-Br-PADAP—羟胺—氯乙酸>体系混配络合物的显色反应,此体系有不同于多数金属离子同型络合物的萃取性质,利于在其他金属离子共存时测定钛。服从比尔定律的范围为0—25μg/25ml。摩尔吸光系数为7.24×10⁴。介绍了合金钢中低含量钛的测定方法。     

Induced Co-colouration and Induced Co-decolouration between Different Rare Earths in the System of 《Metal(Ⅱ)-Rare Earth(Ⅲ)-Chromophoric Reagent-Sensitizer》

In co-colouration systems of rare earth(Ⅲ) with a metal(Ⅱ), induced colouration and decolouration ef-fects between different rare earths have been discovered. A sensitive co-colouration system of 《Lead(Ⅱ)-RareEarth(Ⅲ)-Alizarin Violet-Sensitizer》 was chosen as a typical one to study; and neodymium, gadolinium andyttrium were used to represent light, middle and heavy rare earths respectively. Semiquantitative relationshipsfor the induced effects between yttrium and neodymium as well as between gadolinium and neodymium havebeen determined and discussed. In the presence of a sensitizer, these metal ions cannot always be coloured byalizarin violet when each of them is present alone, but a very sensitive co-colouration or co-decolouration mayoccur during their coexistence under certain conditions. If these metals exist as foreign ions in the photometricdetermination of another metal, serious unperceivable interference will possibly occur. Moreover, the condi-tions leading to induced co-colouration and co-decolouration are very complicated, so that close attention mustbe paid to this area in the photometric determination of certain metals.