Determination of critical properties for binary and ternary mixtures containing dimethyl carbonate and alkanes

2018 ◽  
Vol 137 ◽  
pp. 40-49 ◽  
Author(s):  
Nan Xin ◽  
Chengjie Wang ◽  
Ying Zhang ◽  
Xiangyang Liu ◽  
Maogang He
1974 ◽  
Vol 29 (7) ◽  
pp. 1045-1049
Author(s):  
H. Beßerdich ◽  
E. Kahrig ◽  
Fr. Lange

The pulsation diffusion method is used successfully for the determination of diffusion coefficients in different systems (selfdiffusion, binary and ternary mixtures) and in connection with diffusion separation in liquids. The main advantage is the enhancement of matter transport by periodic flow e. g. in a capillary. Adapting a computation by P. L. Kapiza it is reported on a general treatment for the special conditions in a pulsation diffusion apparatus. Transport behavior depends strongly on hydrodynamic and mass transfer parameters. The results are important for the application of the pulsation method for measuring diffusion coefficients and for separation problems.


2001 ◽  
Vol 69 (4) ◽  
pp. 367-374
Author(s):  
A. Amin ◽  
H. Saleh

A simple, rapid and accurate potentiolnetric method is described for tliedetermination of Os(VIII) in tlie co~icentrationr ange 0.4-4.0 mg/ml. Tlie method isbased on tlie addition of hydralazine hydrochloride to Os(VIII) to reduce it to Os(IV). The excess of hydralazine hydrocliloridew as oxidized by iodine dissolved ill acetic acid. The liberated iodide was then potentiometrically titrated against mercury(II) using silver amalgam as the indicator electrode. The potential of this method for sime- microdetermination is important in practical applications where tlie above reaction should proceed quantitatively towards completion. The relative standard deviation for six replicate deterinination of osmium(VIII) in binary andternary mixtures without the need for extraction or heating.


Fuel ◽  
2016 ◽  
Vol 180 ◽  
pp. 442-447 ◽  
Author(s):  
Camilla Daniela Moura-Nickel ◽  
Lilian Carla Contarti da Cruz ◽  
Luciana Igarashi-Mafra ◽  
Carlos Itsuo Yamamoto ◽  
Marlus Pinheiro Rolemberg ◽  
...  

1988 ◽  
Vol 53 (12) ◽  
pp. 3040-3049 ◽  
Author(s):  
Vladimír Buršík ◽  
Vlastimil Kubáň ◽  
Lumír Sommer

Spectrophotometric methods were employed to study the chelate formation between Fe(III) ions and 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (BrPADAP) in dimethylformamide (φ = 20%) and Triton X-100 (φ = 0·1%). The ML2 chelate with absorption maxima at 535 and 590 nm and molar absorption coefficients of 6·5 and 8·2 m2 mmol-1 is formed quantitatively in the pH interval 3·5 - 4·0 for at least a seven-fold concentration excess of BrPADAP. Concentrations of c(Fe) = 1·6 - 8·1 μmol l-1 can be determined independently in 0·1M acetate buffer with pH 3·6. Iron and copper ions can be determined simultaneously in the presence of zinc ions in binary or ternary mixtures in the concentration ranges c(Fe) = 2 - 8 μmol l-1 and c(Cu) = c(Zn) = 3 - 16 μmol l-1. The relative deviations in the calculated concentrations, Δcr, are 1 - 4% for Fe and up to 5% for Cu in binary and ternary mixtures with equivalent concentrations up to a concentration excess of one component of five-fold in binary mixtures or of one or two components of up to three-fold in ternary mixtures. The simultaneous determination of Zn(II) is accompanied by a Δcr value of up to 30 - 50% and cannot be recommended under the given experimental conditions.


2000 ◽  
Vol 83 (5) ◽  
pp. 1068-1075 ◽  
Author(s):  
María Dolores Gil García ◽  
María Martínez Galera ◽  
Maria Del Carmen Pablos Espada ◽  
Antonia Garrido Frenich ◽  
José Luis Martínez Vidal

Abstract Partial least-squares (PLS) analysis was applied for the first time to ternary and binary mixtures of pesticides producing overlapping peaks in gas chromatograms. Several preprocessing algorithms for pretreatment of data were tested for optimization of the PLS models, and the most advantageous were used in each case. Three different mixtures of pesticides were resolved with satisfactory results: parathion-methyl, chlorpyrifos-methyl, and vinclozolin; parathion-ethyl, chlorpyrifos, and triadimefon; and endosulfan sulfate and carbophenothion. The proposed models were applied to the determination of 3 mixtures of pesticides at levels of 0.02–1.00 ng/mL in wetland water samples after a preconcentration step with C18 cartridges, with recoveries ranging from 82.7 to 117.4%. The reported method is sufficiently sensitive to measure pesticide residues at the maximum allowable concentrations given in the European Union Drinking Water Directive.


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