scholarly journals Comparation of fundamental analytical methods for quantitative determination of copper(II)ion

2008 ◽  
Vol 62 (2) ◽  
pp. 85-89
Author(s):  
Marijana Acanski
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Quantitative Determination ◽  
Gravimetric Analysis ◽  
Heat Conductor ◽  
Electrical Conductor ◽  
Two Samples ◽  
Determination Of Copper ◽  
Gravimetric Procedure

Copper is a ductile metal with excellent electrical conductivity, and finds extensive use as an electrical conductor, heat conductor, as a building material, and as a component of various alloys. In this work accuracy of methods for quantitative determination (gravimetric and titrimetric methods of analysis) of copper(II) ion was studied. Gravimetric methods do not require a calibration or standardization step (as all other analytical procedures except coulometry do) because the results are calculated directly from the experimental data and molar masses. Thus, when only one or two samples are to be analyzed, a gravimetric procedure may be the method of choice because it involves less time and effort than a procedure that requires preparation of standards and calibration. In this work in gravimetric analysis the concentration of copper(II) ion is established through the measurement of a mass of CuSCN and CuO. Titrimetric methods is a process in which a standard reagent is added to a solution of an analyze until the reaction between the analyze and reagent is judged to be complete. In this work in titrimetric analysis the concentration of copper(II) ion is established through the measurement of a volume of different standard reagents: Km, Na2S2O3 and AgNO3. Results were discussed individually and mutually with the aspect of exactility, reproductivity and rapidity. Relative error was calculated for all methods.

scholarly journals A Quantitative Determination of Minimum Film Thickness in Elastohydrodynamic Circular Contacts

2021 ◽  
Author(s):  
Wassim Habchi ◽  
Philippe Vergne
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Numerical Model ◽  
Film Thickness ◽  
Quantitative Determination ◽  
Excellent Agreement ◽  
Operating Conditions ◽  
Pure Rolling ◽  
Minimum Film Thickness

Abstract The current work presents a quantitative approach for the prediction of minimum film thickness in elastohydrodynamic lubricated (EHL) circular contacts. In contrast to central film thickness, minimum film thickness can be hard to accurately measure, and it is usually poorly estimated by classical analytical film thickness formulae. For this, an advanced finite-element-based numerical model is used to quantify variations of the central-to-minimum film thickness ratio with operating conditions, under isothermal Newtonian pure-rolling conditions. An ensuing analytical expression is then derived and compared to classical film thickness formulae and to more recent similar expressions. The comparisons confirmed the inability of the former to predict the minimum film thickness, and the limitations of the latter, which tend to overestimate the ratio of central-to-minimum film thickness. The proposed approach is validated against numerical results as well as experimental data from the literature, revealing an excellent agreement with both. This framework can be used to predict minimum film thickness in circular elastohydrodynamic contacts from knowledge of central film thickness, which can be either accurately measured or rather well estimated using classical film thickness formulae.

Quantitative Determination of Benzaldehyde in Flavors and Cordials by Ultraviolet Spectrophotometry and 2,4-Dinitrophenylhydrazine Precipitation

1967 ◽  
Vol 50 (2) ◽  
pp. 319-322
Author(s):  
Richard L Brunelle
Keyword(s):  
Quantitative Determination ◽  
Spectrophotometric Method ◽  
Alternative Methods ◽  
Ultraviolet Spectrophotometry ◽  
Precipitation Procedure ◽  
Gravimetric Procedure

Abstract Three sets of samples were collaboratively analyzed by the official, first action ultraviolet spectrophotometric and 2,4-dinitrophenylhydrazine precipitation methods for determining benzaldehyde in flavors and cordials. The spectrophotometric method was unchanged, except for clarification, and collaborators reported recoveries averaging nearly 100%. The gravimetric procedure using 2,4-dinitrophenylhydrazine gave unsatisfactory recoveries on the first two sets of collaborative samples. However, collaborators reported approximately 96% recovery of benzaldehyde with a modified precipitation procedure on a third set of samples. The ultraviolet spectrophotometric method and the modified 2,4-dinitrophenylhydrazine precipitation procedure are recommended for adoption as official, final action as alternative methods.

Quantitative Determination of Copper in Natural Rubber

1953 ◽  
Vol 26 (1) ◽  
pp. 251-256 ◽  
Author(s):  
Lewis T. Milliken
Keyword(s):  
Carbon Tetrachloride ◽  
Natural Rubber ◽  
Quantitative Determination ◽  
Oxidation Process ◽  
Aqueous Suspension ◽  
Wet Oxidation ◽  
Acid Extract ◽  
Organic Solution ◽  
Determination Of Copper

Abstract A procedure is recommended in which small amounts of copper in rubber can be measured quantitatively by determining the depth of color of a copper carbamate complex in a carbon tetrachloride solution. The complex is formed in an alkaline solution prepared from an acid extract of the rubber ashed at 550° C. This procedure yields results which are as reliable as those obtained by the more tedious and time-consuming procedures involving the wet-oxidation process which are at present recommended by standardizing organizations. The use of an organic solution rather than an aqueous suspension gives better reproducibility, permits easier use of a photometer, and reduces the interference due to iron by a factor of ten.

2-(2'- Chloro Phenyl)- 5- (2'-Hydroxyl Phenyl)-1,3,4-Oxadiazole as a Florescent Probe for DNA Determination

2011 ◽  
Vol 301-303 ◽  
pp. 361-365
Author(s):  
Mei Ding ◽  
Ying Jie Lei ◽  
Ou Yang Jie
Keyword(s):  
Experimental Data ◽  
Fluorescence Quenching ◽  
Quantitative Determination ◽  
Fluorescent Probe ◽  
Fluorescence Intensity ◽  
Dna Analysis ◽  
Fluorescence Spectrometry ◽  
Experimental Conditions ◽  
Convenient Synthesis

In recent years, fluorescence spectrometry was widely used in quantitative determination of DNA. In this paper, a convenient synthesis of a new fluorescent 2-(2'- Chloro phenyl)- 5- (2'- hydroxyl phenyl)-1,3,4-oxadiazole (HOXD) was realized. Experimental data showed that fluorescence of HOXD could be quenched by DNA and the decreased fluorescence intensity of HOXD resulting from fluorescence quenching is proportional to DNA concentrations suggesting that HOXD could be used as a new fluorescent probe for quantitative determination of DNA. Optimal experimental conditions for DNA analysis were also studied in the paper.

Serum Copper and Iron on a Single Sample

1958 ◽  
Vol 4 (1) ◽  
pp. 43-48 ◽  
Author(s):  
B Zak ◽  
N Ressler
Keyword(s):  
Quantitative Determination ◽  
Serum Sample ◽  
Organic Material ◽  
Serum Copper ◽  
Inorganic Salts ◽  
Organic Extract ◽  
Phenanthroline Complex ◽  
Extract Phase ◽  
Determination Of Copper

Abstract A procedure has been described for the quantitative determination of copper and iron in one serum sample. The sera are wet ashed to destroy organic material, leaving inorganic salts available in the residue for the subsequent spectrophotometric determination of iron as the ferrous-1,10-phenanthroline complex in the aqueous phase, and copper as the cuprous-2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline in an organic extract phase.

Taste and Pitch

1968 ◽  
Vol 27 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Kristian Holt-Hansen
Keyword(s):  
Quantitative Determination ◽  
Experimental Situation ◽  
New Method ◽  
Two Samples ◽  
Pure Tones

This paper describes a new method of quantitative determination of taste. In a special experimental situation S compares taste and pure tones. The latter are varied in pitch until S finds the pitch which characterizes the sample. The method is illustrated by results for two samples, Carlsberg Lager and Carlsberg Elephant Beer. New problems are involved within the psychology of perception.

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