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Rapid determination of zinc in iron ores in the presence of nickel and cobalt.
A 50
Journal of Electroanalytical Chemistry
VOL. 1
F o r t h e d e t e r m i n a t i o n of Cu a n d P b in b o t h e l e c t r o l y t i c t i n a n d h i g h p u r i t y s e l e n i u m b y s q u a r e w a v e p o l a r o g r a p h y , the m o t h e r e l e m e n t s w e r e f i r s t r e m o v e d a n d the Cu a n d P b t h e n d e t e r m i n e d s i m u l t a n e o u s l y in 0.45 N HCIO 4 s u p p o r t i n g e l e c t r o l y t e . S a m p l e s o l u t i o n s of 40 - 60 '¥ C u / 1 0 0 m l a n d 35 - 50 ¥ P b / 1 0 0 m l w e r e d e t e r m i n e d w i t h i n a n e r r o r of 2 - 4 % a n d 4 - 8 % r e s p e c t i v e l y . T h e t i m e n e c e s s a r y for the analysis was relatively short. T a . Fu. [157] A POLAROGRAPHIC STUDY OF SUBSTITUTION REACTIONS OF INORGANIC COMPLEXES. I. REACTION OF THE AuCl4 ION WITH ETHYLENEDIAMINE (in German). P. Beran and A. A. Vl~ek. (Inst. Analyt. Chem. , Charles Univ. , Prague, Czechoslovakia. ) Collect. Czeehoslov. Chem. Communs., 24 (1959) 3572. AuCl= is reduced at a dropping mercury electrode at such positive potentials that onl~ an immediate rise of current caused by the dissolution of mercury is observed. Addition of ethylenediamine causes a decrease of the diffusion-limiting current at positive potentials (about +.0.1 V) with time. Simultaneously a new more negative wave (at about -0.05 V) grows corresponding to the Au(III) ethylenediamine complex. The change of the more positive current with time seems to correspond to a c o m p l i c a t e d r e a c t i o n m e c h a n i s m . F r o m the l i n e a r p a r t of the l o g i - t i m e c u r v e t h e c a l c u l a t e d f i r s t o r d e r r a t e c o n s t a n t k 1 (in the p r e s e n c e of e x c e s s of e t h y l e n e d i a m i n e ) i s a f u n c t i o n of pH a n d a l i n e a r f u n c t i o n of t h e c o n c e n t r a t i o n of ethylene but showing an intercept on the kl-axis. A reaction scheme is suggested in w h i c h AuC14 u n d e r g o e s a c o m p e t i t i v e s i d e r e a c t i o n w i t h p r o t o n i s e d e t h y l e n e diamine and with hydroxyl ions. P. Zu. [1581 R A P I D I ' E T E R M I N A T I O N OF ZINC I N I R O N ORES IN T H E P R E S E N C E OF N I C K E L AND C O B A L T . Y. M i u r a . J a p . A n a l . , 8 (1959) 5. T h e s a m p l e w a s d i s s o l v e d i n a m i x t u r e of HC1 a n d HNO3, e x t r a c t e d w i t h e t h e r to r e m o v e the m a j o r i t y of t h e i r o n a n d t h e n the z i n c d e t e r m i n e d p o l a r o g r a p h i c a l l y in a s o l u t i o n of 1M CH3COOH , 1M CH3COONIt4, 0.03 N N a S C N ~md 0.003% g e l a t i n . C h r o m i u m , m o l y b d e n u m , v a n a d i u m a n d t u n g s t e n i n the o r d i n a r y i r o n o r e s a n d i r o n up to 50 m g d i d n o t i n t e r f e r e i n the a n a l y s i s . F o r t h e s a m p l e c o n t a i n i n g m o r e t h a n 1% z i n c t h e e t h e r e x t r a c t i o n c a n b e o m i t t e d . T a . Fu. [1591 D E T E R M I N A T I O N OF ZINC IN P L A N T ASHES B Y A N O S C I L L O - P O L A R O G R A P H I C METHOD. K. Y a m a m o t o . J a p . A n a l . , 8 ( 1 9 5 9 ) 2 4 5 . The a s h e s of l e a v e s of P r u n u s s a l i c i n a l L i n d l . w e r e a n a l y s e d b y a n a p p a r a t u s u t i l i z i n g a c o m m e r c i a l c a t h o d e r a y o s c i l l o s c o p e . 1.0 g of a s h e s w e r e d i s s o l v e d i n HC1, e v a p o r a t e d to d r y n e s s to r e m o v e SiO2, t h e SiO 2 r e s i d u e b e i n g t r e a t e d w i t h NH4HF 2 + HC1. T h e z i n c w a s e x t r a c t e d f r o m the s o l u t i o n b y d i t h i z o n e - C C 1 4 s o l u t i o n a n d r e - e x t r a c t e d in 0.02 N HC1 s o l u t i o n . An o s c i l l o p o l a r o g r a m w a s o b t a i n e d in a s u p p o r t i n g e l e c t r o l y t e of NH4C1 + NH4OH. Ta. Fu. [160] POLAROGRAPHIC AND OSCILLOGRAPHIC STUDY OF SOME LANTHANIDES (in German). L. Treindl. (Inst. Phys. Chem. , Komensk)} Univ. , Bratisl~va, Czechoslovakia. ) Collect. Czechoslov. Chem. Communso, 24 (1959) 3389. In solutions of lithium hal[des in the presence of La 3+, Ce3+, P r 3+, Nd3+ and Sm3+ a polarographic wave at -1.7 V was observed. This wave, accompanied by a non-turbulent maximum, is neither observed in solutions of other alkali metals nor in the presence of So~-or CIO3. The best developed limiting current was observed in 0.2 M LiCl with 0.2 M Li acetate. For the mean value of the limiting current (il) at regulated drop-times the relation iI -- K . m 075 t 030 was verified. Addition of certain dyestuffs and weak acids caused an elevation of the wave-height
Journal of Electroanalytical Chemistry
VOL. 1
F o r t h e d e t e r m i n a t i o n of Cu a n d P b in b o t h e l e c t r o l y t i c t i n a n d h i g h p u r i t y s e l e n i u m b y s q u a r e w a v e p o l a r o g r a p h y , the m o t h e r e l e m e n t s w e r e f i r s t r e m o v e d a n d the Cu a n d P b t h e n d e t e r m i n e d s i m u l t a n e o u s l y in 0.45 N HCIO 4 s u p p o r t i n g e l e c t r o l y t e . S a m p l e s o l u t i o n s of 40 - 60 '¥ C u / 1 0 0 m l a n d 35 - 50 ¥ P b / 1 0 0 m l w e r e d e t e r m i n e d w i t h i n a n e r r o r of 2 - 4 % a n d 4 - 8 % r e s p e c t i v e l y . T h e t i m e n e c e s s a r y for the analysis was relatively short. T a . Fu. [157] A POLAROGRAPHIC STUDY OF SUBSTITUTION REACTIONS OF INORGANIC COMPLEXES. I. REACTION OF THE AuCl4 ION WITH ETHYLENEDIAMINE (in German). P. Beran and A. A. Vl~ek. (Inst. Analyt. Chem. , Charles Univ. , Prague, Czechoslovakia. ) Collect. Czeehoslov. Chem. Communs., 24 (1959) 3572. AuCl= is reduced at a dropping mercury electrode at such positive potentials that onl~ an immediate rise of current caused by the dissolution of mercury is observed. Addition of ethylenediamine causes a decrease of the diffusion-limiting current at positive potentials (about +.0.1 V) with time. Simultaneously a new more negative wave (at about -0.05 V) grows corresponding to the Au(III) ethylenediamine complex. The change of the more positive current with time seems to correspond to a c o m p l i c a t e d r e a c t i o n m e c h a n i s m . F r o m the l i n e a r p a r t of the l o g i - t i m e c u r v e t h e c a l c u l a t e d f i r s t o r d e r r a t e c o n s t a n t k 1 (in the p r e s e n c e of e x c e s s of e t h y l e n e d i a m i n e ) i s a f u n c t i o n of pH a n d a l i n e a r f u n c t i o n of t h e c o n c e n t r a t i o n of ethylene but showing an intercept on the kl-axis. A reaction scheme is suggested in w h i c h AuC14 u n d e r g o e s a c o m p e t i t i v e s i d e r e a c t i o n w i t h p r o t o n i s e d e t h y l e n e diamine and with hydroxyl ions. P. Zu. [1581 R A P I D I ' E T E R M I N A T I O N OF ZINC I N I R O N ORES IN T H E P R E S E N C E OF N I C K E L AND C O B A L T . Y. M i u r a . J a p . A n a l . , 8 (1959) 5. T h e s a m p l e w a s d i s s o l v e d i n a m i x t u r e of HC1 a n d HNO3, e x t r a c t e d w i t h e t h e r to r e m o v e the m a j o r i t y of t h e i r o n a n d t h e n the z i n c d e t e r m i n e d p o l a r o g r a p h i c a l l y in a s o l u t i o n of 1M CH3COOH , 1M CH3COONIt4, 0.03 N N a S C N ~md 0.003% g e l a t i n . C h r o m i u m , m o l y b d e n u m , v a n a d i u m a n d t u n g s t e n i n the o r d i n a r y i r o n o r e s a n d i r o n up to 50 m g d i d n o t i n t e r f e r e i n the a n a l y s i s . F o r t h e s a m p l e c o n t a i n i n g m o r e t h a n 1% z i n c t h e e t h e r e x t r a c t i o n c a n b e o m i t t e d . T a . Fu. [1591 D E T E R M I N A T I O N OF ZINC IN P L A N T ASHES B Y A N O S C I L L O - P O L A R O G R A P H I C METHOD. K. Y a m a m o t o . J a p . A n a l . , 8 ( 1 9 5 9 ) 2 4 5 . The a s h e s of l e a v e s of P r u n u s s a l i c i n a l L i n d l . w e r e a n a l y s e d b y a n a p p a r a t u s u t i l i z i n g a c o m m e r c i a l c a t h o d e r a y o s c i l l o s c o p e . 1.0 g of a s h e s w e r e d i s s o l v e d i n HC1, e v a p o r a t e d to d r y n e s s to r e m o v e SiO2, t h e SiO 2 r e s i d u e b e i n g t r e a t e d w i t h NH4HF 2 + HC1. T h e z i n c w a s e x t r a c t e d f r o m the s o l u t i o n b y d i t h i z o n e - C C 1 4 s o l u t i o n a n d r e - e x t r a c t e d in 0.02 N HC1 s o l u t i o n . An o s c i l l o p o l a r o g r a m w a s o b t a i n e d in a s u p p o r t i n g e l e c t r o l y t e of NH4C1 + NH4OH. Ta. Fu. [160] POLAROGRAPHIC AND OSCILLOGRAPHIC STUDY OF SOME LANTHANIDES (in German). L. Treindl. (Inst. Phys. Chem. , Komensk)} Univ. , Bratisl~va, Czechoslovakia. ) Collect. Czechoslov. Chem. Communso, 24 (1959) 3389. In solutions of lithium hal[des in the presence of La 3+, Ce3+, P r 3+, Nd3+ and Sm3+ a polarographic wave at -1.7 V was observed. This wave, accompanied by a non-turbulent maximum, is neither observed in solutions of other alkali metals nor in the presence of So~-or CIO3. The best developed limiting current was observed in 0.2 M LiCl with 0.2 M Li acetate. For the mean value of the limiting current (il) at regulated drop-times the relation iI -- K . m 075 t 030 was verified. Addition of certain dyestuffs and weak acids caused an elevation of the wave-height