X-Ray Fluorescence Spectrometric Determination of Rare Earths in Plutonium

1968 ◽  
Vol 22 (5) ◽  
pp. 434-437 ◽  
Author(s):  
E. A. Hakkila ◽  
R. G. Hurley ◽  
G. R. Waterbury
Keyword(s):  
Rare Earths ◽  
Internal Standard ◽  
Internal Standard Method ◽  
X Rays ◽  
Measured Intensity ◽  
X Ray ◽  
Low Concentrations ◽  
Relative Standard ◽  
Intensity Ratios

Two methods were evaluated for determining rare earths in plutonium: (1) For the lighter rare earths ( Z≦66), or low concentrations of the heavier rare earths, an adjacent rare earth was added as a carrier and also as an internal standard, the rare earths were separated from plutonium by fluoride precipitation, and the measured intensity ratios for the sample and for solutions having known concentrations were compared. The Lβ1 x-rays were measured for the lighter rare earths and the Lα1 x rays for the remaining lanthanides. (2) For the heavier rare earths ( Z>66), the Lα1 x-ray intensities were measured from a nitric acid solution of the sample and compared to intensities obtained for solutions having known concentrations. The minimum concentrations that could be measured with a relative standard deviation no greater than 4% by the separation internal standard method varied from approximately 0.5% for lanthanum to 0.01% for lutetium. The direct measurement of x-ray intensity was much less sensitive. Applicability of the methods was shown by successful analyses of plutonium alloys containing dysprosium, thulium, or lutetium.

Quantitative X-ray diffraction analysis of urinary calculi by use of the internal-standard method and reference intensity ratios.

1988 ◽  
Vol 34 (2) ◽  
pp. 289-293 ◽  
Author(s):  
M A Wandt ◽  
A L Rodgers
Keyword(s):  
Standard Method ◽  
Urinary Calculi ◽  
Internal Standard ◽  
Xrd Analysis ◽  
Internal Standard Method ◽  
X Ray Diffraction ◽  
Stone Composition ◽  
X Ray ◽  
Intensity Ratios

Abstract The internal-standard method and the powder diffractometer have been applied here to the quantitative determination of urinary stone constituents by x-ray diffraction (XRD). Reference intensity ratios determined for six stone substances were used in the reduction of intensity data. Constituent concentrations calculated for 21 stones were compared with values obtained from an element-sensitive technique. We conclude that XRD analysis alone cannot be regarded as a routine technique for the quantitative characterization of uroliths, but that semiquantitative XRD analysis supplemented by accurate quantitative elemental data is more suitable for the precise determination of true stone composition.

Intensity and Distribution of Background X-rays in Wavelength Dispersive Spectrometry III

1989 ◽  
Vol 33 ◽  
pp. 521-529
Author(s):  
Tomoya Arai ◽  
Takashi Shoji
Keyword(s):  
Spectroscopic Analysis ◽  
Electron Excitation ◽  
Major Elements ◽  
X Rays ◽  
Fundamental Feature ◽  
X Ray ◽  
Wavelength Dispersive Spectrometry ◽  
Low Concentrations ◽  
Ppm Level

In the spectroscopic analysis of composite elements by x-ray fluorescence (XRF), it is the fundamental feature of this method that the background x-ray intensity is lower than that with electron excitation. However, the background x-rays of this method, which consist of Thomson (Rayleigh) and Compton scattered x-rays from the primary radiation, impair the analytical performance at the ppm level. In order toinvestigate the intensity of the background x-rays precisely,the study was conducted in two parts. The first part compared the measured and theoretically calculated x-ray intensities for Rh Kα and Rh Kβ peaks from various materials. The second part examined the determination of low concentrations of lead,arsenic and colonium in steel samples. The variation in the background x-ray intensities of the analyzed elements was found to be caused by the variation of the major elements and a correction equation for it is derived.

scholarly journals Hydration Study of Synthetic Yeelimite using LXRPD and SXRPD

2014 ◽  
Vol 70 (a1) ◽  
pp. C1096-C1096
Author(s):  
Ana Cuesta ◽  
Gema Alvarez Pinazo ◽  
Angeles De la Torre ◽  
Susana Sanfélix ◽  
Inmaculada Peral ◽  
...  
Keyword(s):  
Standard Method ◽  
Internal Standard ◽  
Free Water ◽  
Ex Situ ◽  
Quantitative Phase Analysis ◽  
Internal Standard Method ◽  
X Rays ◽  
X Ray ◽  
External Standard Method

XRPD is a powerful tool for material characterization in general, and for in-situ studies of chemical processes in particular. The use of an intense X-ray source, .i.e. synchrotron X-rays, coupled with fast X-ray detection permits time-resolved diffraction experiments allowing in-situ quantitative phase analysis during the early ages of cement hydration. Calcium sulfoaluminate, CSA, cements may have variable compositions, but all of them contain high amounts of ye'elimite, Ca4Al6O12SO4. Commercial CSA cements have special applications such as high strength developments at early-ages. Ye'elimite is very reactive and most of its hydration heat is released during the first eight hours of hydration . The aim of this work is to better understand the early age hydration of stoichiometric (orthorhombic) and doped (pseudo-cubic) ye'elimite samples. The parameters studied by SXRPD, LXRPD and calorimetry have been: polymorphism; water/ye'elimite ratio; and sulfate (gypsum and anhydrite) contents. This work has allowed establishing mechanisms and kinetics for hydration of ye'elimite samples by in-situ SXRPD with internal standard methodology. Moreover, pastes were also studied by ex-situ LXRPD with the external standard method, G-factor, at 2 and 7 days. Both strategies were able to quantify the amorphous contents, including free water. It is important to highlight that the results obtained at early ages, by the internal standard method, are in agreement with those obtained at later ages, G-method, showing the consistence and complementarity of both methodologies. The hydration of stoichiometric ye'elimite in the presence of gypsum is strongly hastened, when compared to the hydration process without gypsum. However, the presence of gypsum has a little effect in the hydration of doped ye'elimite. Moreover, anhydrite has also accelerated the hydration of stoichiometric ye'elimite, although its lower solubility has provoked the formation of an intermediate phase in the first hours.

scholarly journals Development and Validation of a New Method for Determination of Pb and Cr in Marine Organisms by Total Reflection X-Ray Fluorescence (TXRF) Spectroscopy

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Blanca G. Beltrán ◽  
Ibiza Martínez-Serrano ◽  
Victor Ramos-Sanchez ◽  
David Chávez-Flores ◽  
Myrna C. Nevárez-Rodríguez ◽  
...  
Keyword(s):  
Internal Standard ◽  
Chelonia Mydas ◽  
Sample Volume ◽  
Marine Organisms ◽  
Total Reflection ◽  
X Ray ◽  
Relative Standard ◽  
Sample Frequency ◽  
Development And Validation

Lead and chromium contamination represents one of the most serious problems in the aquatic environments. The aim of this work was to develop and validate an accurate, sensitivity, and rapid method for the simultaneous determination of Pb and Cr at trace levels in tissues and fat of marine organisms such as turtle (Chelonia mydas), shark (Rhizoprionodon terraenovae), and dolphin (Tursiops truncatus), utilizing the total reflection X-Ray fluorescence (TXRF) spectroscopy. Working solutions were prepared in 10 mL of a solution 0.005 mol·L−1 EDTA and 1 mol·L−1 HNO3. In order to correct possible instrument drifts, 20 μg·L−1 of gallium was used as internal standard (IS). The results showed that TXRF method was linear over the concentration ranges of 5.242–100 μg·L−1 for Pb and 2.363–100 μg·L−1 for Cr. Limits of detection (LOD) achieved were 1.573 and 0.709 μg·L−1 for Pb and Cr, respectively, while limits of quantification achieved were 5.242 μg·L−1 for Pb and 2.363 μg·L−1 for Cr. The validated method was accurate and precise enough for determination of these heavy metals in samples of marine organisms as indicated by acceptable values of recovery between 90–101%. In addition, a certified reference material (BCR-279, sea lettuce) and a Centrum tablet were satisfactory analyzed, and the T-test for comparison of means revealed that there were no significant differences at the 95% confidence level between the values obtained with the proposed TXRF method and the certificated values. The repeatability of the method, expressed as relative standard deviation (RSD), was 5.1% and 4%, for Pb and Cr, respectively. In addition, other features of the developed method were a low sample volume of 10 μL, and the sample frequency achieved was 20 h−1.

Determination of Ethanol in Fermented Broth by Headspace Gas Chromatography using Capillary Column

2018 ◽  
Vol 69 (11) ◽  
pp. 2969-2972
Author(s):  
Asem Hassan Mohammed ◽  
Alaa Kareem Mohammed ◽  
Firas Hashim Kamar ◽  
Aseel Abdulqader Abbas ◽  
Gheorghe Nechifor
Keyword(s):  
Gas Chromatography ◽  
Capillary Column ◽  
Internal Standard ◽  
Accurate Method ◽  
Volatile Components ◽  
Internal Standard Method ◽  
Significance Level ◽  
Relative Standard ◽  
Fermented Broth

The gas chromatography (GC) method in analytical chemistry is a quick and accurate method to detect volatile components like ethanol. A method for determining volatile components known as Headspace chromatography (HS-GC) was developed along with an internal standard method (ISM) to identify ethanol in fermented broth in the laboratory. The aim of this research is determining the concentration of ethanol in fermented broth using capillary column (ZB-1). This method can analyze ethanol concentrations in the fermented medium broth ranging from 10 to 200 g/L. The validation of this method was done in order to obtain the results to be of high precision and the significant, precision was represented as the relative standard deviation (RSD) which was less than 5%, accuracy was less than 4 % and significance level was p [ 0.05. It was found that this method exhibited good reproducibility.

Application of Capillary Zone Electrophoresis in the Separation and Determination of the Tertiary Butylhydroquinone

2011 ◽  
Vol 361-363 ◽  
pp. 683-686
Author(s):  
Qian Xiang ◽  
Ying Gao
Keyword(s):  
Capillary Zone Electrophoresis ◽  
Internal Standard ◽  
Amperometric Detection ◽  
Internal Standard Method ◽  
Tertiary Butylhydroquinone ◽  
Peak Intensity ◽  
Relative Standard ◽  
Zone Electrophoresis ◽  
Capillary Zone

We describe the use of capillary zone electrophoresis (CZE) for the determination of tertiary butylhydroquinone (TBHQ) without derivatization or purification. The influences of buffer pH and voltage on the separation of TBHQ were studied. The internal standard method was used for the quantification of TBHQ. Amperometric detection was carried out at an applied potential of 0.80 V. The detection limit of TBHQ was found to be 10-6 M. Peak intensity varied linearly with TBHQ concentration from 10-4 to 5×10-6 M. The relative standard deviation (RSD) for peak intensity and migration time was in the range of 3.58–4.36% and 0.51–0.94%, respectively. The recovery of the method in food samples is 95.36% for TBHQ. The method developed is suitable for the routine analysis of synthetic phenolic antioxidant TBHQ in samples.

Determination of Migration of 11 Organotin Compounds in Food Contact Materials by GCMS

2020 ◽  
Vol 984 ◽  
pp. 58-63
Author(s):  
Guang Bao Ye
Keyword(s):  
Internal Standard ◽  
Liquid Solution ◽  
Organotin Compounds ◽  
Internal Standard Method ◽  
Method Detection Limit ◽  
Contact Materials ◽  
Food Contact Materials ◽  
Food Contact ◽  
Relative Standard

The determination of the migration of 11 organotin compounds in food contact materials by GC-MS was established. The gastric acid was simulated with 0.07 mol/L hydrochloric acid solution, and the sample was soaked and extracted, and then derivatized with sodium tetraethylborate, extracted with n-hexane liquid solution, detected by GC-MS, and quantified by internal standard method. The linear range of the method is 5~600 μg/L, the correlation coefficient is greater than 0.997, and the method detection limit is 0.014 mg/kg. The recoveries of the three concentration levels ranged from 83.6% to 105.6% with a relative standard deviation of less than 11.4%. The method is simple and sensitive, and can be used for detecting the migration of organotin compounds in food contact materials.

Sign in / Sign up

Export Citation Format

Share Document