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.

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.

scholarly journals Preliminary Studies on Liquiritin, Deoxyschizandrin, and Tanshinone II A as Potential Anti-Neurodegenerative Disease Agent: Determination by Reverse-Phase Liquid Chromatography in Tianwang Buxin Pills

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Dan Xu ◽  
Sicen Wang ◽  
Xiaofang Hou ◽  
Changshan Sun
Keyword(s):  
Phosphoric Acid ◽  
Neurodegenerative Disease ◽  
Standard Method ◽  
Internal Standard ◽  
Acetonitrile Solution ◽  
Array Detector ◽  
Internal Standard Method ◽  
Tanshinone Ii A ◽  
External Standard Method ◽  
External Standard

Tianwang Buxin pill (TWBXP) is an ancient Chinese classic prescription. Liquiritin, deoxyschizandrin, and tanshinone II A are three bioactive components in TWBXP, which have been proven to be closely related to the therapy effect of neurodegenerative disease. Their contents are very low in TWBXP. In this study, we used a diode array detector (DAD) to perform a full wavelength scanning in order to choose a most suitable detection wavelength to establish an HPLC method for the simultaneous determination of these three components in TWBXP. Various chromatographic conditions were investigated to verify its applicability. Finally, a Kromasil C18 column (250 × 4.6 mm, 5 μm) thermostated at 30°C, mobile phase as 0.2% phosphoric acid solution (eluent A), and 0.1% phosphoric acid-acetonitrile solution (eluent B) were used. Both external standard method and internal standard method were used for quantification. The results showed that both methods were simple and convenient in operation without special pretreatment and exhibits excellent precision, repeatability (RSD < 3.0%), good linearity (R2 > 0.9990), and good recoveries (recovery value between 95% and 105%). Because of the low contents in samples, the internal standard method provided a better accurate result than the external standard method. The stability results showed the sample became stable within 24 hours at room temperature. The method provides a convenient and effective way for the quality control of TWBXP, and it can help the research about AD in the future.

Quantitative in situ X-ray diffraction analysis of early hydration of Portland cement at defined temperatures

2009 ◽  
Vol 24 (2) ◽  
pp. 112-115 ◽  
Author(s):  
C. Hesse ◽  
F. Goetz-Neunhoeffer ◽  
J. Neubauer ◽  
M. Braeu ◽  
P. Gaeberlein
Keyword(s):  
Portland Cement ◽  
Free Water ◽  
Xrd Analysis ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
Early Hydration ◽  
X Ray ◽  
Main Period ◽  
Diffraction Patterns

Investigation into the early hydration of Portland cement was performed by in situ X-ray diffraction (XRD). Technical white cement was used for the XRD analysis on a D5000 diffractometer (Siemens). All diffraction patterns of the in situ measurement which were recorded up to 22 h of hydration at defined temperatures were analyzed by Rietveld refinement. The resulting phase composition was transformed with respect to free water and C-S-H leading to the total composition of the cement paste. The hydration reactions can be observed by dissolution of clinker phases as well as by the formation of the hydrate phases ettringite and portlandite. With increasing temperatures the reactions proceed faster. The formation of ettringite is directly influenced by the rate of dissolution of anhydrite and tricalcium aluminate (C3A). The beginning of the main period of hydration is marked by the start of portlandite formation. The experiments point out that a quantitative phase analysis of the cement hydration is feasible with standard laboratory diffractometers.

STANDARD-FREE METHOD FOR HOOF SAMPLES TAKEN FROM DOMESTIC ANIMALS SUCH AS COW, CALF, PONY AND SHEEP

2009 ◽  
Vol 19 (03n04) ◽  
pp. 111-122 ◽  
Author(s):  
K. SERA ◽  
K. SUZUKI ◽  
K. TAGUCHI ◽  
J. ITOH ◽  
S. GOTO ◽  
...  
Keyword(s):  
Standard Method ◽  
Elemental Concentration ◽  
Internal Standard ◽  
Domestic Animals ◽  
The State ◽  
Preparation Technique ◽  
Internal Standard Method ◽  
X Rays ◽  
State Of Health ◽  
Cow Calf

A standard-free method for hoof samples taken from cattle such as cow, calf, pony and sheep has been developed in order to estimate the state of health of these animals. The standard-free method developed for human nails was confirmed to be applicable to quantitative analysis of hoof samples since the shape of continuous X-rays is almost the same for nail and hoof taken from these ungulate animals. Accuracy and sensitivity of the present standard method were examined by comparing the results with those obtained by an internal-standard method combined with a chemical-ashing method, and it is confirmed that the method is applicable to hoof samples taken from domestic animals of many species. The method allows us to quantitatively analyze untreated hoof samples and to prepare the targets without complicated preparation technique which often brings ambiguous factors such as elemental loss from the sample and contamination of the sample during preparation procedure. It is also confirmed that halogens, which are important elements for estimating the state of health and are mostly lost during chemical-ashing, can be analyzed without problem by the present method. It is found that elemental concentration of more than twenty elements can be constantly analyzed and it is expected to be quite useful in order to estimate the state of health and to make diagnosis of domestic animals. It is also confirmed that elemental concentration of essential elements in hoof is not so changed depending on the positions in the sliced sample along both horizontal and vertical axis.

scholarly journals RIR - Measurement and Use in Quantitative XRD

1988 ◽  
Vol 3 (2) ◽  
pp. 74-77 ◽  
Author(s):  
Camden R. Hubbard ◽  
Robert L. Snyder
Keyword(s):  
Quantitative Analysis ◽  
Powder Diffraction ◽  
Internal Standard ◽  
Quantitative Phase Analysis ◽  
Internal Standard Method ◽  
Reference Standard ◽  
Powder Diffraction File ◽  
X Ray ◽  
Independent Constant ◽  
General Instrument

AbstractThe Reference Intensity Ratio (RIR) is a general, instrument-independent constant for use in quantitative phase analysis by the X-ray powder diffraction internal standard method. When the reference standard is corundum, RIR is known as I/Ic; These constants are collected in the Powder Diffraction File (1987), can be calculated, and can be measured. Recommended methods for accurate measurement of RIR constants are presented, and methods of using these constants for quantitative analysis are discussed. The numerous, complex constants in Copeland and Bragg's method introduced to account for superimposed lines can be simply expressed in terms of RIR constants and relative intensities. This formalism also permits introduction of constraints and supplemental equations based on elemental analysis.

STANDARD-FREE METHOD OF QUANTITATIVE ANALYSIS FOR BIO-SAMPLES

1996 ◽  
Vol 06 (03n04) ◽  
pp. 467-481 ◽  
Author(s):  
K. SERA ◽  
S. FUTATSUGAWA ◽  
K. MATSUDA ◽  
Y. MIURA
Keyword(s):  
Quantitative Analysis ◽  
Standard Method ◽  
Present Method ◽  
Total Yield ◽  
Internal Standard ◽  
Bovine Liver ◽  
Internal Standard Method ◽  
X Rays ◽  
Tissue Samples ◽  
Almost All

Internal Standard Method, which has been widely used for quantitative analysis of general bio-samples, requires certain skill in sample preparation since it sometimes accompanies a noticeable error due not only to inaccuracy of weight measurement both of a sample and of an internal standard but also to nonuniformity of the internal standard in the target. In this work, a standard-free method of quantitative analysis, based on the fact that the total yield of continuous x-rays from the sample approximately corresponds to effective weight of the sample, has been developed and applied to some typical bio-samples (NIST Bovine liver, a rat liver and a human serum). As a result, values of concentration obtained by the present method present good agreement with those obtained by the internal standard method. Further, in a case where target preparation is performed by unskilled person, the present method gives better results than those obtained by the internal standard method. It is also found that this method is applicable to almost all soft-tissue samples and, moreover, to targets prepared by a different method.

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