Absolute isothermal-distillation method of determination of osmotic pressure

1964 ◽  
Vol 29 (1) ◽  
pp. 24-35 ◽  
Author(s):  
K. Šolc ◽  
E. Erdös
2014 ◽  
Vol 1073-1076 ◽  
pp. 197-201
Author(s):  
Jun Mei Zhao ◽  
Hui Chao Bi ◽  
Yi Li ◽  
Hai Chao Bi

Purpose The flow injection distillation (zinc acetate solution) was changed to be 5% phosphoric acid in the method of determination of cyanide. Application Cyanide in groundwater was measured by FIA6000 + automatic flow injection analyzer directly. Results In the 2.0-100.0μg/L range, the linear correlation coefficient was greater than 0.9, the recovery was 86.1% -100.8%, relative standard deviation 1.3% -3.8%. Conclusion This method not only reduces the white crystals [Zn (OH)2] on the pump tube blockage, making the operation more simple and efficient, but also for the detection of a large number of groundwater samples.


2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Camilo Fuentes Serrano ◽  
Juan Reinaldo Estevez Alvares ◽  
Alfredo Montero Alvarez ◽  
Ivan Pupo Gonzales ◽  
Zahily Herrero Fernandez ◽  
...  

A method for determination of Cr, Fe, Co, Ni, Cu, Zn, Hg and Pb in waters by Energy Dispersive X Ray Fluorescence (EDXRF) was implemented, using a radioisotopic source of 238Pu. For previous concentration was employed a procedure including a coprecipitation step with ammonium pyrrolidinedithiocarbamate (APDC) as quelant agent, the separation of the phases by filtration, the measurement of filter by EDXRF and quantification by a thin layer absolute method. Sensitivity curves for K and L lines were obtained respectively. The sensitivity for most elements was greater by an order of magnitude in the case of measurement with a source of 238Pu instead of 109Cd, which means a considerable decrease in measurement times. The influence of the concentration in the precipitation efficiency was evaluated for each element. In all cases the recoveries are close to 100%, for this reason it can be affirmed that the method of determination of the studied elements is quantitative. Metrological parameters of the method such as trueness, precision, detection limit and uncertainty were calculated. A procedure to calculate the uncertainty of the method was elaborated; the most significant source of uncertainty for the thin layer EDXRF method is associated with the determination of instrumental sensitivities. The error associated with the determination, expressed as expanded uncertainty (in %), varied from 15.4% for low element concentrations (2.5-5 μg/L) to 5.4% for the higher concentration range (20-25 μg/L).


Author(s):  
P.F. Collins ◽  
W.W. Lawrence ◽  
J.F. Williams

AbstractA procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate


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