On the possibility of separate determination of uranium and thorium on the basis of data from measurements of the gamma emission spectra of their ores in place

Atomic Energy ◽  
1962 ◽  
Vol 12 (1) ◽  
pp. 76-78
Author(s):  
S. G. Troitskii ◽  
V. L. Shashkin ◽  
K. I. Bykova
Keyword(s):  
Emission Spectra ◽  
Separate Determination ◽  
Gamma Emission

Separate Determination of Liquid Properties with Lamb Wave Devices

2006 ◽  
Author(s):  
Zhijun Chen ◽  
Tao Han ◽  
Wenkang Shi ◽  
Xiaojun Ji ◽  
Lianger Li
Keyword(s):  
Lamb Wave ◽  
Separate Determination

Polarographic determination of oxygen content and capacity in a single blood sample

1965 ◽  
Vol 20 (4) ◽  
pp. 774-778 ◽  
Author(s):  
Domenic A. Maio ◽  
James R. Neville
Keyword(s):  
Blood Sample ◽  
Oxygen Content ◽  
Rapid Determination ◽  
Mercury Electrode ◽  
Potassium Ferricyanide ◽  
Separate Determination ◽  
Polarographic Method ◽  
Dropping Mercury Electrode ◽  
Single Blood Sample

A polarographic method was described in an earlier report which permits the accurate, rapid determination of oxygen content in small samples of blood. As with the Van Slyke technic, total oxygen capacity was formerly estimated by a separate determination of the oxygen content after complete saturation with oxygen of another portion of the blood sample. Further experience with the polarographic method has revealed the feasibility of estimating both content and capacity in a single blood sample. The capacity estimate is made possible by the polarographic observation of the quantity of potassium ferricyanide required to convert ferrohemoglobin to ferrihemoglobin. The measurement of oxygen content is performed, as previously described, by the polarographically determined increase in physically dissolved oxygen caused by the release of bound oxygen. By this means, one avoids sampling and random errors inherent in the use of two separate determinations. The method requires only a brief time for performance and ordinary technical proficiency. It is also simple in application. polarographic dropping mercury electrode; oxygen tension; digitonin; potassium ferricyanide; ferrohemoglobin; ferrihemoglobin Submitted on June 24, 1964

scholarly journals Optimization of the Conditions for Determining 2,4-D and Deltamethrin by HPLC

2020 ◽  
Vol 20 (4) ◽  
pp. 372-377
Author(s):  
Elena V. Melikhova ◽  
◽  
Olga V. Farafonova ◽  
Keyword(s):  
River Water ◽  
Chromatographic Determination ◽  
Capillary Columns ◽  
Dichlorophenoxyacetic Acid ◽  
Separate Determination ◽  
Isocratic Elution ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Gradient Mode

The paper presents the results of optimizing the conditions for the chromatographic determination of 2,4-dichlorophenoxyacetic acid and deltamethrin for two capillary columns (Supelcosil LC-18, Kromasil C-18). The modes of individual chromatography of pesticides were selected. The use of the isocratic elution mode in the joint presence of 2,4-dichlorophenoxyacetic acid and deltamethrin was shown and experimentally proved to be invalid. Three options were proposed for the conditions of the gradient mode of the separate detection of analytes in a mixture. The developed technique for the chromatographic separate determination of 2,4-D and deltamethrin with their joint presence was tested via analysis of river water and potato samples.

scholarly journals Study of the component composition of organic matter of the East Pre-Caucasian basin rocks based on the results of lithological, petrophysical and geochemical studies

Georesursy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 66-72
Author(s):  
R.S. Khisamov ◽  
Natalia Skibitskaya ◽  
Nikita Samokhvalov ◽  
Kazimir Kovalenko ◽  
Oleg Navrotsky
Keyword(s):  
Organic Matter ◽  
Component Composition ◽  
Separate Determination ◽  
Weight Concentration ◽  
Kerogen Type ◽  
Low Concentrations ◽  
Close Relationship ◽  
Geochemical Investigation ◽  
Geochemical Studies

This study introduces results of lithological, petrophysical and geochemical investigation of Lower Cretaceous (K1) and Middle Jurassic (J2a-b) rocks of East Pre-Caucasian basin. According to pyrolytic and bituminological studies method of separate determination of kerogen and bitumen concentration been developed. In accordance with this method differentiation of organic matter components in different lithotypes of rocks been described. Also relationship between bitumen and kerogen concentrations been revealed. The majority of samples have poor to fair organic richness and poor source potential. Kerogen type is commonly presented by type III and stages of maturity characterized by stages PC3 to MC3. Bitumen compounds have low concentrations of asphaltenes and aromatic hydrocarbons and mainly contains light and heavy resins. Based on petrophysical and geochemical studies a close relationship between the concentration of organic carbon and the weight concentration of potassium nuclides was obtained. This relationship indicates that kerogen in the sediments under consideration is associated with clay minerals, which is also confirmed by the mineral composition of the rocks.

Determination of the gamma emission intensities of 125Xe based on 125I radioactivity

2022 ◽  
pp. 109967
Author(s):  
Feng Xie ◽  
Jianfeng Liang ◽  
Bin Chen ◽  
Quanlin Shi ◽  
Xuesong Li ◽  
...  
Keyword(s):  
Gamma Emission

Arrays of solid contact potentiometric sensors for separate determination of some cephalosporin antibiotics

2021 ◽  
Vol 87 (5) ◽  
pp. 5-13
Author(s):  
E. G. Kulapina ◽  
A. E. Dubasova ◽  
O. I. Kulapina ◽  
V. D. Ankina
Keyword(s):  
Response Time ◽  
Reference Model ◽  
Complex Compounds ◽  
Potentiometric Sensors ◽  
Separate Determination ◽  
Solid Contact ◽  
Active Components ◽  
Membrane Surfaces ◽  
Cephalosporin Antibiotics

Arrays of potentiometric sensors including developed solid-contact unmodified and modified sensors based on tetradecylammonium associates with complex compounds of silver (1) and some β-lactam antibiotics (cefazoline, cefuroxime, cefotaxime (n = 3 – 6)) are proposed; polyaniline and copper oxide being modifiers. The main electroanalytic properties of the sensors are determined (the range of the determined concentrations in antibiotic solutions 1 × 10–4 – 0.1 M, 46.3 < S < 48, Cmin = n × 10–5 М, response time 4 – 10 sec, potential drift 4 – 6 mV/day, service life — 2 months). It is shown that modification of the membrane surfaces brings the steepness of the electrode functions to Nernst-values for single-charged ions of the antibiotics under study; reduces the response time and the detection limits, the linearity intervals of the electrode functions being the same. The potentiometric selectivity coefficients of unmodified and modified sensors based on different electrode active components (EAC) to the studied cephalosporins in the presence of interfering antibiotics are close to unity; cross sensitivity parameters for the considered sensors (the average slope of the electrode function of the sensor Sav, the unselectivity factor F, and the reproducibility factor K) are 46.3 < S (mV/pC) < 48; 0.85 < F < 0.90; 144 < K < 170, respectively. Application of sensors in the multisensory analysis of model mixtures of cephalosporin antibiotics is shown. Method of artificial neural networks (ANN) is used for processing of analytical signals. The correctness of the determination is carried out using «spike tests» on the reference model mixtures (the relative error of the determination does not exceed 12 %).

scholarly journals A New Sensitive Fluorirnetric Method for the Determination of Heptaminol and Mexiletine in Pharmaceuticals

2002 ◽  
Vol 70 (1) ◽  
pp. 57-65 ◽  
Author(s):  
EI-Adl Sobhy M.
Keyword(s):  
Sodium Salt ◽  
Emission Spectra ◽  
Reaction Conditions ◽  
Pharmaceutical Excipients ◽  
Reference Methods ◽  
Acid Sodium Salt ◽  
Spectrofluorimetric Method

An accurate and very sensitive spectrofluorimetric method is proposed for the estimation of heptaminol (HP) and mexiletine (MX) in their pure forms and in pharlnaceutical formulations. The method is based on the reaction of these drugs with the strong fluorigenic reagent [9,1O-Dimethoxy-2-anthracenesulfonic acid sodium salt (DAS)] at pH (2.5). The formed complexes are extracted into chloroform and measured spectrofluori~netrically. The maximum wavelengths of excitation and emission spectra of heptaminol complex are 381 and 441 m, respectively. While those of mexiletine complex are 385 and 450 nrn, respectively. Heptaminol can be determined in the concentration range of 0.016-0.144 µg ml−1 and that of mexiletine in the range of 0.024-0.176 µg ml−1, when extracted from the solutions into chloroform. Different parameters affecting the reaction conditions were thoroughly studied. No interference was observed in the presence of common pharmaceutical excipients. The proposed method has been successfully applied to the analysis of commercial pharmaceutical fonnulations and the results have been statistically compared with those obtained by the reference methods.

Liquid Chromatographic Screening Method for Fluorescent Derivatives of Chlorophenoxy Acid Herbicides in Water

1992 ◽  
Vol 75 (4) ◽  
pp. 720-724 ◽  
Author(s):  
Toshinari Suzuki ◽  
Satoru Watanabe
Keyword(s):  
Solid Phase Extraction ◽  
Water Samples ◽  
Solid Phase ◽  
Screening Method ◽  
Ethyl Esters ◽  
Separate Determination ◽  
Phase Extraction ◽  
Liquid Chromatographic ◽  
Acid Herbicides

Abstract A liquid chromatographic method for screening 9 chlorophenoxy acids (2,4-D; 2,4-DP; 2,4-DB; MCPA; MCPP; MCPB; 2,4,5-T; 2,4,5-TP; and 2,4,5-TB) and their ethyl esters in ground- and tap water is presented. The water samples are acidified and subjected to either liquid-liquid or solid-phase extraction. The extracts obtained are saponified in 0.03N NaOH-50% methanol (1+1) and the acidic compounds are re-extracted with ethyl acetate-n-hexane (8 + 2) after acidification and derivatized with 9- anthryldiazomethane. Derivatized compounds are analyzed using reversed-phase column chromatography with fluorescence detection (excitation, 365 nm; emission, 412 nm). Recoveries of analytes from 20 mL water samples were greater than 90%, and the average coefficient of variation was within 5.0% at 0.5 ppb for both extraction methods. These methods are simple and useful for the determination of small amounts of chlorophenoxy herbicides. Solid-phase extraction is suitable for screening a large number of samples simultaneously, and liquid extraction for separate determination of the acids and ethyl esters of the herbicides was improved by introducing a saponification step.

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