scholarly journals Fast determination of the surface density of titanium in ultrathin layers using LIBS spectrometry

2014 ◽  
Vol 29 (10) ◽  
pp. 1806-1812 ◽  
Author(s):  
Tomáš Kratochvíl ◽  
Tomáš Černohorský ◽  
Petr Knotek ◽  
Lukáš Kalina ◽  
Jakub Návesník ◽  
...  
Keyword(s):  
Surface Density ◽  
Fast Method ◽  
Fast Determination ◽  
Steel Sheets ◽  
Ultrathin Layers ◽  
Precise Quantification

A new ultra fast method for precise quantification of very low surface densities of Ti deposited on steel sheets.

scholarly journals Precise Method of Ambiguity Initialization for Short Baselines with L1-L5 or E5-E5a GPS/GALILEO Data

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4318 ◽  
Author(s):  
Mieczysław Bakuła
Keyword(s):  
Mobile Phones ◽  
Double Difference ◽  
Fast Method ◽  
Short Baseline ◽  
Fast Determination ◽  
Gnss Receivers ◽  
Short Baselines ◽  
Relative Errors ◽  
Gps Observations

This paper presents a precise and fast method of ambiguity resolution (PREFMAR) for frequencies L1/E1 and L5/E5a of GPS/GALILEO data. The developed method is designed for precise and fast determination of ambiguities in GNSS phase observations. Ambiguities are chosen based on mathematical search functions. The fact that no variance–covariance matrix (VC matrix) with a so-called float solution is needed proves the innovativeness of the developed method. The developed method enables determination of the ambiguities for short baseline double-difference (DD) observations. The presented algorithms for the developed method enable unique and reliable calculation of the ambiguity if the actual errors of code measurements of DD observations are less than 0.38 m and the relative errors of phase observations are in the range of ±3 cm. The paper presents both mathematical derivations of the functions used in the PREFMAR and numerical calculations based on real double-difference GPS observations (L1-L5). The elaborated algorithms can be easily implemented into GNSS receivers or mobile phones. Therefore, they can be widely used in many geoscience applications, as well as in precise GPS/GALILEO navigation.

Simple and Fast Determination of Terbinafine in Human Urine by Dilute and Shoot HPLC-DAD Using a Core-Shell Column

2020 ◽  
Vol 23 ◽  
Author(s):  
Sercan Yıldırım ◽  
Gökhan Demirdaş ◽  
Mert Fidan ◽  
Ahmet Yaşar
Keyword(s):  
Flow Rate ◽  
Human Urine ◽  
Mobile Phase ◽  
Limit Of Detection ◽  
Therapeutic Drug ◽  
Core Shell ◽  
Pharmacokinetic Studies ◽  
Fast Method ◽  
Fast Determination

Background: Terbinafine is an allylamine antifungal which is effective against many fungi, dermatophytes and moulds. Analytical methods are required for the determination of terbinafine in biological fluids to perform therapeutic drug monitoring and pharmacokinetic studies. Objective: The aim of this study was to develop and validate a novel and fast method combining dilute and shoot approach and high-performance liquid chromatography coupled with photodiode array detection for the determination of terbinafine in human urine. Methods: Chromatographic parameters including mobile phase composition, pH, flow rate and injection volume was assessed and optimized. The separation of terbinafine and naproxen (internal standard) was achieved within 3 min using a C18 core-shell column (Raptor ARC-18, 100 x 4.6 mm, 2.7 µm) under isocratic conditions. Samples were eluted from the column at the flow rate of 1.4 mL/min using a mobile phase containing 0.2% triethylamine in water (pH 3.4 with formic acid): acetonitrile (45:55, v/v). Results: Presented technique was linear in the range of 25-2000 ng/mL. Intra- and inter-day reproducibility at four quality control levels (25, 200, 750 and 1500 ng/mL) was less than 7%, with relative errors ranging from -5.40% to 5.91%. Limit of detection was 12.60 ng/mL. Developed method has three main advantages compared to existing methods: simplicity and greenness of sample preparation, use of core-shell column and short analysis time. Conclusion: The results of this study indicate that the combination of dilute and shoot approach and core-shell column can be regarded as an advantageous application for the fast determination of terbinafine in urine.

Simple and fast determination of thimerosal in vaccines using dilute acids and cold vapor atomic fluorescence spectrometry (CV AFS)

2021 ◽  
Author(s):  
Maria Janaína de Oliveira ◽  
Francisco Cunha ◽  
Josue Carinhanha
Keyword(s):  
Mercury Compound ◽  
Fluorescence Spectrometry ◽  
Atomic Fluorescence Spectrometry ◽  
Fast Method ◽  
Organic Mercury ◽  
Atomic Fluorescence ◽  
Fast Determination ◽  
Cold Vapor ◽  
Organic Mercury Compound

A simple and fast method was developed for the determination of thimerosal (TH) in vaccines based on decomposition through the action of oxidizing systems of the organic mercury compound to...

Fast determination of diphenhydramine, pyridoxine, and 8-chlorotheophylline by capillary electrophoresis with capacitively coupled contactless conductivity detection

2016 ◽  
Vol 8 (22) ◽  
pp. 4432-4437 ◽  
Author(s):  
Michelle M. A. C. Ribeiro ◽  
Jhonys M. Freitas ◽  
Rodrigo A. A. Muñoz ◽  
Claudimir L. do Lago ◽  
Eduardo M. Richter
Keyword(s):  
Capillary Electrophoresis ◽  
Simultaneous Determination ◽  
Fast Method ◽  
Conductivity Detection ◽  
Fast Determination ◽  
Capacitively Coupled ◽  
Contactless Conductivity Detection

This work reports a new and fast method for the simultaneous determination of diphenhydramine, pyridoxine, and 8-chlorotheophylline by CE-C4D.

Determination L-Arginine from Grape Juice with Sakaguchi Reaction

2013 ◽  
Vol 662 ◽  
pp. 301-304 ◽  
Author(s):  
Xin Hong Liang ◽  
Jun Liang Sun ◽  
Song Ling Chen ◽  
Ying Bin Fan
Keyword(s):  
Grape Juice ◽  
Ethyl Carbamate ◽  
Fast Method ◽  
Wine Yeasts ◽  
Buffer Solution ◽  
Fast Determination ◽  
Cation Exchange Resins ◽  
Glass Column ◽  
Exchange Resins

Arginine in grape juice can be metabolized by wine yeasts to precursors of ethyl carbamate. The aim of this study was to develop a simple, accurate and fast method for determining arginine in grape juice by separating L-arginine with strong cation-exchange resins. The results showed that the optimized parameters as follows: 16g of pretreated resins packed in a glass column (D1.0×30cm), and 10.0mL of testing sample (pH = 2.0) added to the columns, kept for 20min at 20°C, then rinsed with pH 8.0 buffer solution. Finally, it was eluted with 300 mL 1 mol•L-1 NaOH at the rate of 2mL mol•min-1. The optimized method in combination with Sakaguchi reagents was simple, reproducible and accurate. This method can be applied for quick and fast determination of arginine in grape juice to take necessary action and avoid the forming of ethyl carbamate.

Fast Method for the Determination of Residual Solvents in Radiopharmaceutical Products

2017 ◽  
Vol 68 (4) ◽  
pp. 666-670 ◽  
Author(s):  
Mirela Mihon ◽  
Catalin Stelian Tuta ◽  
Alina Catrinel Ion ◽  
Dana Niculae ◽  
Vasile Lavric
Keyword(s):  
Gas Chromatography ◽  
Control Method ◽  
Limit Of Detection ◽  
The Body ◽  
Biologically Active ◽  
Injection Technique ◽  
Fast Method ◽  
Residual Solvent ◽  
Residual Solvents

The aim of this work was the development and validation of a fast analytical method to determine the residual solvents content in radiopharmaceuticals such as: 18F-Fluorodeoxyglucose (18F-FDG), 18F-Fluoroestradiol (18F-FES), 18F-Fluorothymidine (18F-FLT),18F-Fluoromisonidazole (18F-FMISO). Radiopharmaceuticals are radioactive preparations for medical purposes used in nuclear medicine as tracers in diagnostic imaging and treatment of certain diseases. Positron Emission Tomography (PET) is a medical imaging technique that consists in introducing into the body of a small amount of a biologically active chemical compound labelled with a short lived positron-emitting radioisotope (18F, 11C, 68Ga). Residual solvents are critical impurities in radiopharmaceuticals that can affect labelling, stability and physicochemical properties of drugs. Therefore, the determination of these solvents is essential for quality control of radiopharmaceuticals. Validation of the control method for residual solvents by gas chromatography is referred by the European Pharmacopoeia using a special injection technique (head space). The parameters of the method, which comply with International Conference on Harmonization guidelines, are: accuracy, precision, linearity, limit of detection, limit of quantification and robustness. The proposed method (direct gas chromatography injection) proved to be linear, precise, accurate and robust. Good linearity was achieved for all the solvents and correlation coefficients (R2) for each residual solvent were found more than 0.99.

Fast determination of the degree of methyl esterification of pectins by head-space GC

2004 ◽  
Vol 18 (4) ◽  
pp. 665-668 ◽  
Author(s):  
M.M.H Huisman ◽  
A Oosterveld ◽  
H.A Schols
Keyword(s):  
Fast Determination ◽  
Methyl Esterification ◽  
Head Space
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