Division of the analytical signal into arcing half-periods and correction of results of the determination of La and Y in geological samples

1980 ◽  
Vol 32 (3) ◽  
pp. 216-221
Author(s):  
A. N. Kapitonov ◽  
M. A. Alekseev ◽  
V. S. Suknev
Keyword(s):  
Analytical Signal ◽  
Geological Samples

Dc arc emission analysis of rare earth metals and their oxides with sorption preconcentration of impurities

2018 ◽  
Vol 84 (11) ◽  
pp. 9-14
Author(s):  
E. S. Koshel ◽  
V. B. Baranovskaya ◽  
M. S. Doronina
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Analytical Signal ◽  
Graphite Powder ◽  
Atomic Emission ◽  
Standard Samples ◽  
Emission Analysis ◽  
Sorption Preconcentration ◽  
Sample Shape

The analytical capabilities of arc atomic emission determination of As, Bi, Sb, Cu, Te in rare earth metals (REM) and their oxides after preparatory group concentration using S,N-containing heterochain polymer sorbent are studied on a high-resolution spectrometer “Grand- Extra” (“WMC-Optoelectron-ics” company, Russia). Sorption kinetics and dependence of the degree of the impurity extraction on the solution acidity are analyzed to specify conditions of sorption concentration. To optimize the procedure of arc atomic emission determination of As, Bi, Sb, Cu, and Te various schemes of their sorption preconcentration and subsequent processing of the resulted concentrate with the addition of a collector at different stages of the sorption process have been considered. Graphite powder is used as a collector in analysis of rare earth oxides due to universality and relative simplicity of the emission spectrum. Conditions of analysis and parameters of the spectrometer that affect the analytical signal (mass and composition of the sample, shape and size of the electrodes, current intensity and generator operation mode, interelectrode spacing, wavelengths of the analytical lines) are chosen. The evaporation curves of the determinable impurities were studied and the exposure time of As, Bi, Sb, Cu, and Te in the resulted sorption concentrate was determined. Correctness of the obtained results was evaluated using standard samples of the composition and in comparisons between methods. The results of the study are used to develop a method of arc chemical-atomic emission analysis of yttrium, gadolinium, neodymium, europium, scandium and their oxides in a concentration range of n x (10-2 - 10-5) wt.%.

Simultaneous and Sensitive Determination of Amphetamine, Codeine and Morphine in Exhaled Breath Condensate, Using Capillary Electrophoresis Coupled with On-line and Off-line Enhancing Methods

2020 ◽  
Vol 16 (7) ◽  
pp. 872-879
Author(s):  
Samin Hamidi
Keyword(s):  
Drugs Of Abuse ◽  
Exhaled Breath Condensate ◽  
Direct Injection ◽  
Forensic Toxicology ◽  
Analytical Signal ◽  
Exhaled Breath ◽  
Concentration Method ◽  
Validation Parameters ◽  
Breath Condensate

Background: Abuse of drugs is associated with several medical, forensic, toxicology and social challenges. “Drugs of abuse” testing is therefore an important issue. Objective: We propose a simple CE-based method for the quantification of amphetamine, codeine and morphine after direct injection of Exhaled Breath Condensate (EBC) by the aid of simple stacking mode and an off-line pre-concentration method. Methods: Using graphene oxide adsorbents, amphetamine, codeine and morphine were extracted from EBC in order to eliminate the proteins and other interferences. In addition to off-line method, an online stacking mode was applied to improve the analytical signal obtained from the instrument. Results: The validation parameters were experimented on the developed method based on the FDA guideline over concentration ranges of 12.5-100, 30-500 and 10-1250 ng/mL associated with amphetamine, codeine and morphine, respectively. Small volumes (around 100 μL) of EBC were collected using a lab-made setup and successfully analyzed using the proposed method where precisions and accuracies (within day and between days) were in accordance with the guideline (recommended less than 15 % for biological samples). The recovery tests were used to evaluate the matrix effect and data (94 to 105 %) showed that the proposed method can be applied in different EBC matrix samplings of subjects. Conclusion: The proposed method is superior for simultaneous determination of amphetamine, codeine and morphine over chromatographic analyses because it is fast and consumes fewer chemicals, with no derivatization step.

scholarly journals An SPRi Biosensor for Determination of the Ovarian Cancer Marker HE4 in Human Plasma

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3567
Author(s):  
Beata Szymanska ◽  
Zenon Lukaszewski ◽  
Beata Zelazowska-Rutkowska ◽  
Kinga Hermanowicz-Szamatowicz ◽  
Ewa Gorodkiewicz
Keyword(s):  
Ovarian Cancer ◽  
Cancer Patients ◽  
Tumor Resection ◽  
Analytical Signal ◽  
Cancer Marker ◽  
Human Epididymis Protein 4 ◽  
Pearson Coefficient ◽  
Rabbit Polyclonal Antibody ◽  
Good Agreement

Human epididymis protein 4 (HE4) is an ovarian cancer marker. Various cut-off values of the marker in blood are recommended, depending on the method used for its determination. An alternative biosensor for HE4 determination in blood plasma has been developed. It consists of rabbit polyclonal antibody against HE4, covalently attached to a gold chip via cysteamine linker. The biosensor is used with the non-fluidic array SPRi technique. The linear range of the analytical signal response was found to be 2–120 pM, and the biosensor can be used for the determination of the HE4 marker in the plasma of both healthy subjects and ovarian cancer patients after suitable dilution with a PBS buffer. Precision (6–10%) and recovery (101.8–103.5%) were found to be acceptable, and the LOD was equal to 2 pM. The biosensor was validated by the parallel determination of a series of plasma samples from ovarian cancer patients using the Elecsys HE4 test and the developed biosensor, with a good agreement of the results (a Pearson coefficient of 0.989). An example of the diagnostic application of the developed biosensor is given—the influence of ovarian tumor resection on the level of HE4 in blood serum.

ANALYSIS OF SOLDERS ON TIN AND LEAD BASES BY X-RAY FLOORESCENT SPECTROSCOPY

2021 ◽  
pp. 124-131
Author(s):  
A.V. Alekseev ◽  
◽  
G.V. Orlov ◽  
P.S. Petrov ◽  
A.V. Slavin ◽  
...  
Keyword(s):  
Emission Spectroscopy ◽  
High Resolution Mass Spectrometry ◽  
Analytical Signal ◽  
Atomic Emission ◽  
Standard Samples ◽  
X Ray ◽  
Fundamental Parameters ◽  
The Matrix ◽  
Resolution Mass

The determination of the elements Cu, Ni, Sb, Bi, Pb, Zn and Fe in the tin-based solder VPr35, as well as the elements Sn, Ni, Sb, Bi and In in the lead-based VPr40 solder by the method of х-ray fluorescence spectroscopy has been carried out. The calibration dependences are corrected taking into account the superposition of signals from interfering elements on the analytical signal and changes in intensity caused by inter-element influences in the matrix. The analysis was carried out by the method of fundamental parameters without using standard samples. The correctness of the results obtained was confirmed by their comparative analysis by atomic emission spectroscopy and high-resolution mass spectrometry with a glow discharge.

Laser fluorescence determination of lead in geological samples when vaporized by pulsed laser light

1992 ◽  
Vol 56 (3) ◽  
pp. 235-238 ◽  
Author(s):  
O. N. Ezhov ◽  
B. R. Kano ◽  
S. V. Oshemkov ◽  
A. A. Petrov
Keyword(s):  
Laser Light ◽  
Pulsed Laser ◽  
Laser Fluorescence ◽  
Geological Samples ◽  
Fluorescence Determination

X-ray spectral determination of gold in geological samples after its concentration by low-temperature fire assay

2016 ◽  
Vol 52 (14) ◽  
pp. 1440-1443 ◽  
Author(s):  
V. A. Simakov ◽  
V. E. Isaev
Keyword(s):  
Low Temperature ◽  
Spectral Determination ◽  
Geological Samples ◽  
Fire Assay ◽  
X Ray
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