Use of a New Versatile Interactive Regression Analysis Program for X-Ray Fluorescence Analysis

1979 ◽  
pp. 375-384 ◽  
Author(s):  
W. N. Schreiner ◽  
R. Jenkins
Keyword(s):  
Regression Analysis ◽  
Fluorescence Analysis ◽  
Analysis Program ◽  
X Ray

Use of a New Versatile Interactive Regression Analysis Program for X-Ray Fluorescence Analysis

1978 ◽  
Vol 22 ◽  
pp. 375-384 ◽  
Author(s):  
W. N. Schreiner ◽  
R. Jenkins
Keyword(s):  
Regression Analysis ◽  
Fluorescence Analysis ◽  
Mass Storage ◽  
Analysis Program ◽  
Correction Model ◽  
X Ray ◽  
Line Intensities ◽  
The Past ◽  
Computer Controlled ◽  
Measured Line

XRF can be a powerful tool for quantitative elemental analysis-it can also be a big headache. The problem is, of course, that to perform a proper quantitative analysis one needs to first develop a good matrix correction model to convert the measured line intensities to concentrations. For empirical models, aside from the inherent difficulties in optimizing a set of interelement correction coefficients, the commercially available computer controlled spectrometers have in the past either provided rather poor regression analysis programs with their software or none at all. The reason for this has been the rather limited core size of the online computer and the lack of fast efficient mass storage facilities such as floppy disks.

Examples of Analysis from an Integrated X-Ray Fluorescence Analysis System Using NRLXRF

1981 ◽  
Vol 25 ◽  
pp. 81-84
Author(s):  
B. E. Artz ◽  
M. J. Rokosz
Keyword(s):  
Energy Dispersive Spectrometer ◽  
Fluorescence Analysis ◽  
Fundamental Parameter ◽  
Analysis Program ◽  
X Ray ◽  
Fundamental Parameters ◽  
Xrf Analysis ◽  
Parameters Analysis ◽  
Analysis System ◽  
Preparation Techniques

Methods of correction for matrix differences are required in X-ray Fluorescence (XRF) Analysis when the overall composition of the unknowns is substantially different from the available standards. Sample preparation techniques used to minimize matrix differences often require development time and can consume irreplaceable sample material. Alternatively, the increasing computer power available to the analyst and the refinement of computer programs using fundamental parameter calculations has made this approach more attractive.A system-consisting of a Siemens SRS-1 wavelength dispersive spectrometer (WDS), a KEVEX 0810-A/NS880 energy dispersive spectrometer (EDS), software for data collection and manipulation and a 40 element version of the NRLXRF fundamental-parameters analysis program has been put together to simplify XRF analysis of samples lacking standards of a similar composition. This configuration is shown schematically in Figure I.

Statistical Considerations in X-Ray Fluorescence Analysis

1975 ◽  
Vol 19 ◽  
pp. 53-73 ◽  
Author(s):  
M. A. Short
Keyword(s):  
Regression Analysis ◽  
Standard Deviation ◽  
Least Squares ◽  
Multiple Regression Analysis ◽  
Multiple Regression ◽  
Fluorescence Analysis ◽  
Single Element ◽  
X Ray ◽  
Experimental Parameters

The role of statistics in certain areas of X-ray fluorescence analysis is considered. The topics discussed include: calculating the standard deviation associated with the result of an analysis; optimizing experimental parameters for both wavelength and energy dispersive analyses; evaluating limits of detection, limits of decision, and limits of determination; and weighting in the least squares fitting of data in single element polynomial relationships and in multi-element multiple regression analysis.

Contamination Indexes in Degerminated Corn Products

1968 ◽  
Vol 51 (2) ◽  
pp. 338-346
Author(s):  
Charles E Curtis
Keyword(s):  
Regression Analysis ◽  
Data Analysis ◽  
Stream Flow ◽  
Extraction Methods ◽  
Weighted Regression ◽  
Analysis Program ◽  
X Ray ◽  
Corn Products ◽  
Weighted Regression Analysis ◽  
Corn Processing

Abstract Insect and rodent contamination in corn milling was studied to improve current methodology and recommend new methodology. Representative whole corn processing equipment, degerminators, grading equipment, and finished products were sampled. Whole corn samples were examined visually and by X-ray techniques; all samples were examined by heavy and light filth extraction methods similar to AOAC procedures. Whenever possible, contaminant counts throughout the system were weighted for stream flow before analyzing and presenting data. WRAP (Weighted Regression Analysis Program) was used in data analysis. The least number of equivalent whole exoskeletons gave the best correlations with radiograph data (r2 values ranging from 57.1 to 69.1%) of any of three methods used to report insects of kernel interior origin recovered in cracking-flotation of whole corn samples. The second trapping in light filth extractions was valuable in recovering additional rodent hairs, insects, and insect fragments from all types of corn and mill samples.

An x-ray microprobe based upon a close-coupled focal-spot / glass capillary arrangement

1992 ◽  
Vol 50 (2) ◽  
pp. 1758-1759
Author(s):  
D. A. Carpenter ◽  
M. A. Taylor
Keyword(s):  
Imaging Techniques ◽  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Specimen Preparation ◽  
X Rays ◽  
Glass Capillary ◽  
Close Coupling ◽  
X Ray ◽  
Point To Point ◽  
Beam Damage

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.

XRMF applications of a monolithic, polycapillary, focusing x-ray optic

1996 ◽  
Vol 54 ◽  
pp. 240-241
Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla
Keyword(s):  
Trace Elements ◽  
Point Source ◽  
Focal Spot ◽  
Fluorescence Analysis ◽  
X Rays ◽  
Focal Distance ◽  
Spot Diameter ◽  
X Ray ◽  
Focal Spot Diameter

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.

Sorption of Se (IV) from aqueous solutions with subsequent determination by X-ray fluorescence analysis

2020 ◽  
Vol 86 (10) ◽  
pp. 5-9
Author(s):  
D. G. Filatova ◽  
A. A. Arkhipenko ◽  
M. A. Statkus ◽  
V. V. Es’kina ◽  
V. B. Baranovskaya ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Fluorescence Analysis ◽  
Standard Samples ◽  
Phase Contact Time ◽  
Sorbent Phase ◽  
X Ray ◽  
Fundamental Parameters ◽  
Inductively Coupled ◽  
Subsequent Determination

An approach to sorptive separation of Se (IV) from solutions on a novel S,N-containing sorbent with subsequent determination of the analyte in the sorbent phase by micro-x-ray fluorescence method is presented. The sorbent copolymethylenesulfide-N-alkyl-methylenamine (CMA) was synthesized using «snake in the cage» procedure and proven to be stable in acid solutions. Conditions for quantitative extraction of Se (IV) were determined: sorption in 5 M HCl or 0.05 M HNO3 solutions when heated to 60°C, phase contact time being 1 h. The residual selenium content in the solution was determined by inductively coupled plasma mass spectrometry (ICP-MS) using 82Se isotope. The absence of selenium losses is proved and the mechanism of sorption interaction under specified conditions is proposed. The method of micro-x-ray fluorescence analysis (micro-RFA) with mapping revealed a uniform distribution of selenium on the sorbent surface. The possibility of determining selenium in the sorbent phase by micro-RFA is shown. When comparing the obtained results with the results of calculations by the method of fundamental parameters, it is shown the necessity of using standard samples of sorbates to obtain correct results of RFA determination of selenium in the sorbent phase.

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