IMPROVEMENT OF SAMPLE PREPARATION IN ICP-AES ANALYSIS OF FERROALLOYS

2019 ◽  
Vol 85 (5) ◽  
pp. 11-17
Author(s):  
I. I. Chernikova ◽  
K. Y. Tumneva ◽  
T. Y. Bakaldina ◽  
T. N. Ermolaeva
Keyword(s):  
Sample Preparation ◽  
Internal Standard ◽  
Analytical Signal ◽  
Precise Determination ◽  
Standard Samples ◽  
Microwave Sample Preparation ◽  
Wide Range ◽  
Significant Difference ◽  
Temperature Time

A set of ICP-AES techniques has been developed for determination of rated elements: Ti, Si, R Al, Cu, Mo, V, Sn, and Zr in ferrotitanium; Ni, Fe, Cu, Co, and As in ferronickel; Si, Cr, and P in ferrochrome silicon; Zr, Si, Al, R and Cu in zirconium ferrosilicon; Mn, Si, and P in manganese ferrosilicon. Combination of the multi-element ICP-AES method which allows precise determination of the elements in ferroalloys in a wide range of concentrations and microwave sample preparation in closed autoclaves which excludes the loss of the components to be determined provides the rapidity of the analysis procedure. The composition of solutions for opening samples of ferroalloys and temperature-time modes of microwave sample preparation in an autoclave are substantiated. Conditions for ICP-AES determination of the rated elements in ferroalloys are studied. Analytical lines of the elements to be determined free from significant spectral overlaps are chosen. The dilution rates of the solutions are determined. The method of internal standard was used to improve the reproducibility of the analytical signal for Ti determination in ferrotitanium, Si and Cr in ferrochrome silicon, as well as all rated elements in manganese ferrosilicon and ferronickel. The spectrometer was calibrated using model solutions and solutions of standard samples added with the certified solutions of the elements to be determined. To determine Ti, Si, FJ Al, Cu, У and Zr in ferrotitanium; Ni, Fe, Cu, and Co in ferronickel; Si, Cr, and P in ferrochrome silicon; Zr, Si, Al, P, and Cu in zirconium ferrosilicon; Si and P in manganese ferrosilicon a multidimensional graduation by two analytical lines was used. The correctness of the determination was evaluated in analysis of standard samples of ferroalloys and comparative analysis of the obtained results with the data of standard methods: comparison of the variances according to the Fisher criterion did not reveal any significant difference between them, whereas the use of the modified Student test showed the absence of the systematic error.

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.%.

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.

Simultaneous determination of Rivaroxaban and TAK-438 in rat plasma by LC–MS/MS: application to pharmacokinetic interaction study

Bioanalysis ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 11-22 ◽  
Author(s):  
Libin Wang ◽  
Shouchang Gai ◽  
Xiaorui Zhang ◽  
Xiaohui Xu ◽  
Nan Gou ◽  
...  
Keyword(s):  
Drug Interactions ◽  
Internal Standard ◽  
Pharmacokinetic Interaction ◽  
Rat Plasma ◽  
Pharmacokinetic Parameters ◽  
Interaction Study ◽  
Significant Difference ◽  
Us Fda ◽  
First Time

Aim: A sensitive and reliable LC–MS/MS method has been established and validated to the quantitation of rivaroxaban (RIV) and TAK-438 in rat plasma using carbamazepine as internal standard. Results: The procedure of method validation was conducted according to the guidelines of EMA and US FDA. At the same time, the method was applied to pharmacokinetic interactions study between RIV and TAK-438 for the first time. When RIV and TAK-438 co-administration to rats, main pharmacokinetic parameters of TAK-438 like AUC(0-t), AUC(0-∞) and Cmax had statistically significant increase. The main pharmacokinetic parameters of RIV have no statistically significant difference (p > 0.05) when co-administered except for t1/2 (p < 0.01). Conclusion: The results indicated that drug–drug interactions occurred between RIV and TAK-438 when co-administered to rats.

Determination of /V-Nitrosodipropylamine in Trifluralin Emulsifiable Concentrates Using Minicolumn Cleanup and Gas Chromatography with Thermal Energy Analyzer

1988 ◽  
Vol 71 (2) ◽  
pp. 333-336
Author(s):  
Dave Wotherspoon ◽  
Ralph Hindle
Keyword(s):  
Gas Chromatography ◽  
Thermal Energy ◽  
Internal Standard ◽  
Energy Analyzer ◽  
Quick Method ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
Artifact Formation ◽  
And Control

Abstract A quick method for determining /V-nitrosodipropylamine (NDPA) levels in trifluralin emulsifiable concentrate formulations is described. At least 18 samples can be analyzed at one time in a minimum of fumehood space, with up to 90% savings on solvents and materials. A sample aliquot is mixed with a solution containing nitrosamine recovery standards, and nitrosamines are separated by minicolumn cleanup. Internal standard is added directly to the eluate containing the nitrosamines, and levels are determined by gas chromatography with thermal energy analyzer. Recoveries of spiked nitrosamines ranged from 98 to 102%. Coefficients of variation for samples containing 0.5 ppm NDPA are 13%. Minimum detectable limit, calculated as 3 times the noise, is 0.06 ppm. Comparison with the method formerly used by this laboratory shows no significant difference in the analytical results at 95% confidence limits, and control experiments were performed to ensure that there was no artifact formation of NDPA.

Determination Of Tryptophan Content In Infant Formulas And Medical Nutritionals

1992 ◽  
Vol 75 (6) ◽  
pp. 1112-1119 ◽  
Author(s):  
Saul E Garcia ◽  
Jeffrey H Baxter
Keyword(s):  
Internal Standard ◽  
Enzymatic Digestion ◽  
Reversed Phase ◽  
Infant Formulas ◽  
Free Tryptophan ◽  
Relative Standard ◽  
Wide Range ◽  
Time Requirements ◽  
Tryptophan Content

Abstract A method was developed for determination of total tryptophan content in soy- and milk-based nutritional products. The method uses enzymatic (pronase) digestion of the protein to release tryptophan, which is separated and quantitated by isocratic reversed-phase liquid chromatography with fluorescence detection. Enzymatic digestion is completed for products containing these types of proteins in less than 6 h and is accomplished under chemically mild conditions (pH 8.5,50°C), which do not significantly degrade tryptophan. Chromatographic separation is complete in about 8 min, including an internal standard. The precision of the method is 1-2% relative standard deviation. Accuracy is demonstrated by agreement with theoretical values for standard proteins (amino acid sequence known) and by quantitative recoveries of overspikes, which use either free tryptophan or a standard protein as the spiking material. The method allows determinations on samples containing a wide range of tryptophan values. Appropriate sample size selection and verification of digestion time requirements should allow the method to be applied to different protein types as well. The method allows 24 h turnaround of tryptophan analyses, and quantitative recoveries represent a significant improvement on existing techniques applied to infant formulas and other nutritional products.

Chromatographic Study of Azintamide in Bulk Powder and in Pharmaceutical Formulation in the Presence of Its Degradation Form

2017 ◽  
Vol 100 (2) ◽  
pp. 422-428 ◽  
Author(s):  
Maha A Hegazy ◽  
Waleed A Hassanain ◽  
Laila E Abdel Fattah ◽  
Hamed M El-Fatatry
Keyword(s):  
Quantitative Determination ◽  
Degradation Product ◽  
Internal Standard ◽  
Reversed Phase ◽  
Pharmaceutical Formulation ◽  
Chromatographic Study ◽  
Significant Difference ◽  
Tlc Plates ◽  
Acidic Degradation

Abstract Two specific, sensitive, and precise stability-indicating chromatographic methods were developed, optimized, and validated for the determination of Azintamide (AZ) in the presence of its degradation product. The first method was TLC combined with the densitometric determination of the separated bands. Separation was achieved using silica gel 60 F254 TLC plates and chloroform–acetone–glacial acetic acid (7.5 + 2.1 + 0.4, v/v/v) as the developing system. Good correlations were obtained between the integrated peak area of the studied drug and its corresponding concentrations in the linearity range. The second method used HPLC with UV diode-array detection, in which the proposed method was applied for the quantitative determination of AZ in the presence of its acidic degradation product and the quantitative determination of the acid-induced degradation product of AZ (AZ Deg) using pentoxifylline as the internal standard. The proposed components were separated on a reversed-phase C18 analytical column using acetonitrile–water (50 + 50, v/v). The flow rate was maintained at 0.55 mL/min and the detection wavelength was 260 nm. Linear regressions were obtained in the range of 1–30 and 0.3–16 μg/mL for AZ and AZ Deg, respectively. Different parameters affecting the suggested methods were optimized for maximum separation of the cited components. The suggested methods were validated in compliance with the International Conference on Harmonization guidelines and successfully applied for the determination of AZ in its pure powder form and in its pharmaceutical formulation. Both methods were also statistically compared with the reported method with no significant difference in performance observed.

Use of Stabilized Plasma Arc Excitation in Determining the Element Boron in Gasoline

1965 ◽  
Vol 19 (2) ◽  
pp. 57-58 ◽  
Author(s):  
M. S. Vigler ◽  
J. K. Failoni
Keyword(s):  
Standard Deviation ◽  
Sample Preparation ◽  
Ethyl Alcohol ◽  
Coefficient Of Variation ◽  
Internal Standard ◽  
National Bureau ◽  
Plasma Arc ◽  
Buffer Solution ◽  
Arc Excitation

This report describes the use of a stabilized plasma arc source in the quantitative spectrographs determination of boron in gasoline. The advantage is that the plasma arc requires no preliminary sample preparation other than addition of nickel hexoate internal standard in ethyl alcohol buffer solution. The National Bureau of Standards # 1063 menthyl borate may be used for preparing calibration curves. The method is applicable to the determination of boron in the range of 0.0001 to 0.0010 per cent. The standard deviation is 0.000055 per cent; the coefficient of variation is 8.1 per cent.

Sign in / Sign up

Export Citation Format

Share Document