The stability of the cobaltous thiocyanate complex in ethyl alcohol-water mixtures and the photometric determination of cobalt

The Analyst ◽  
1947 ◽  
Vol 72 (860) ◽  
pp. 478 ◽  
Author(s):  
Norbert Uri
1979 ◽  
Vol 44 (11) ◽  
pp. 3264-3274 ◽  
Author(s):  
Nguyen Truong Son ◽  
Eduard Ružička ◽  
Jan Lasovský

The reactions of four dyes of the alizarin green series with UO22+ ions in the presence of cetyltrimethylammonium cation (CTA+, S) were studied. At lower tenside concentration than the critical micelle concentration (cmc), defined ternary UO2L2S4 or UO2L2S2 complexes are formed in the solution. The stability constants of the complexes formed were determined and a procedure for the photometric determination of uranium and cetyltrimethylammonium was proposed.


The Analyst ◽  
1997 ◽  
Vol 122 (10) ◽  
pp. 1045-1048 ◽  
Author(s):  
Pablo Richter ◽  
M. Inés Toral ◽  
Emely Fuenzalida ◽  
Pablo Richter ◽  
A. Eugenia Tapia

2019 ◽  
Vol 85 (7) ◽  
pp. 16-21
Author(s):  
Liliya R. Mubarakova ◽  
German K. Budnikov

Sultones are cyclic esters of hydroxysulfonic acids, which are formed in the process of sulfonation of α-olefins with sulfur trioxide gas. More stable sultones may be present in the final product — an anionic surfactant — sodium α-olefin sulfonate (AOC-Na). AOC-Na is widely used in the production of household chemicals and cosmetic products, including liquid dishwashing detergents. Sultones are strong skin sensitizers, their level in AOC-Na should be strictly controlled and not exceed 5 ppm. Operational and strict control of the sultone content upon AOC-Na production allows timely adjustment at the stage of hydrolysis, which leads to a more complete disclosure of the sultone cycle with the formation of the corresponding olefin sulfonates and hydroxyalkanesulfonates. We propose a method for determining δ-hexadecansultone in liquid dishwashing detergents and sodium α-olefinsulfonates obtained on the basis of α-olefins of C14 – C16 fractions using GC/MS, which provides shortening of sample preparation and keeps the sensitivity with a detection limit of 0.02 mg/kg. The effect of various weakly polar and non-polar organic solvents used for Sultone extraction from AOC-Na and liquid detergent on liquid extraction based on the dispersion of the extractant in an alcohol/water phase is studied. When selecting the solvent we have shown that the use of diethyl ether provided the best extraction of the analyte. Determination of the analyte extraction recovery was performed using the reaction of hydrolysis of the extracted mixture. We specified the operating mode of the device which provided complete separation of the components of the analyzed compounds including the samples of liquid detergent for dishes being a multicomponent mixture of complex composition.


2019 ◽  
Vol 85 (10) ◽  
pp. 23-28
Author(s):  
F. S. Aliyeva ◽  
F. O. Mamedova ◽  
F. N. Bahmanova ◽  
Yu. A. Yusibov ◽  
F. M. Chyragov

Author(s):  
Sunny Katyara ◽  
Lukasz Staszewski ◽  
Faheem Akhtar Chachar

Background: Since the distribution networks are passive until Distributed Generation (DG) is not being installed into them, the stability issues occur in the distribution system after the integration of DG. Methods: In order to assure the simplicity during the calculations, many approximations have been proposed for finding the system’s parameters i.e. Voltage, active and reactive powers and load angle, more efficiently and accurately. This research presents an algorithm for finding the Norton’s equivalent model of distribution system with DG, considering from receiving end. Norton’s model of distribution system can be determined either from its complete configuration or through an algorithm using system’s voltage and current profiles. The algorithm involves the determination of derivative of apparent power against the current (dS/dIL) of the system. Results: This work also verifies the accuracy of proposed algorithm according to the relative variations in the phase angle of system’s impedance. This research also considers the varying states of distribution system due to switching in and out of DG and therefore Norton’s model needs to be updated accordingly. Conclusion: The efficacy of the proposed algorithm is verified through MATLAB simulation results under two scenarios, (i) normal condition and (ii) faulty condition. During normal condition, the stability factor near to 1 and change in dS/dIL was near to 0 while during fault condition, the stability factor was higher than 1 and the value of dS/dIL was away from 0.


Sign in / Sign up

Export Citation Format

Share Document