Determination of sulfate, orthophosphate, and triphosphate ions by flow injection analysis with the lead ion selective electrode as detector

1986 ◽  
Vol 58 (3) ◽  
pp. 608-611 ◽  
Author(s):  
J. F. Coetzee ◽  
C. W. Gardner



1981 ◽  
Vol 46 (2) ◽  
pp. 368-376 ◽  
Author(s):  
Josef Veselý

Titration of sulphates with lead perchlorate employing lead ion selective electrode indication was studied using additions of various organic solvents at different pH' and ionic strength values. As the optimum emerged systems with 60-70% 1,4-dioxane, pH' 5.3-5.6. After dehydration with sodium hydroxide, dioxane must be freed from the electrode surface-oxidizing impurities by their reduction with sodium metal and subsequent distillation. The method was applied to determination of sulphates in mountain spring waters. Units of ppm can be determined; the limit of determination, however, depends considerably on the content of dioxane, total salt content in the sample, and speed of the semi-automatic titration. Lead can be determined with EDTA in concentrations down to c(Pb2+) = 5 . 10-6 mol l-1.



2016 ◽  
Vol 13 (2) ◽  
pp. 458-469
Author(s):  
Baghdad Science Journal

A simple, fast, selective of a new flow injection analysis method coupled with potentiometric detection was used to determine vitamin B1 in pharmaceutical formulations via the prepared new selective membranes. Two electrodes were constructed for the determination of vitamin B1 based on the ion-pair vitamin B1-phosphotungestic acid (B1-PTA) in a poly (vinyl chloride) supported with a plasticized di-butyl phthalate (DBPH) and di-butyl phosphate (DBP). Applications of these ion selective electrodes for the determination of vitamin B1 in the pharmaceutical preparations for batch and flow injection systems were described. The ion selective membrane exhibited a near-Nernstian slope values 56.88 and 58.53 mV / decade, with the linear dynamic range of vitamin B1 was 5 x 10-5- 1 x 10-2 and 1 x 10-4-1 x 10-2 mol.L-1, in batch and FIA, respectively. The limit of detection was 3.5 x 10-5 and 9.5 x 10-5 mol.L-1, with the percentage linearity 98.85 and 95.22 in batch and FIA, respectively. The suggested ion selective electrode has been utilized perfection in the determination of vitamin B1 in pharmaceutical formulations using batch and flow injection system, respectively.





1979 ◽  
Vol 62 (2) ◽  
pp. 315-319
Author(s):  
Saad S M Hassan ◽  
Mohamed T Zaki ◽  
Mohamed H Eldesouki

Abstract Simple, rapid, and accurate methods have been developed for determining vitamin Bx in pharmaceutical preparations without prior separation of the vitamin. The methods are based on the desulfurization reaction with potassium plumbite and measurement of the unreacted lead (II) ions at 217 nm using atomic absorption spectroscopy (AAS), or by titration with EDTA at pH 4.5 with the lead ion selective electrode and Gran's plot. The results compare favorably with those obtained using the USP fluorometric method. Recoveries of pure vitamin Bx averaged 99.1%, with a standard deviation of 0.8%, and 99.0%, with a standard deviation of 0.7%, for the AAS and ion selective electrode procedures, respectively.



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