Evaluation of single sample clearance calculations in 902 patients

1997 ◽  
Vol 38 (1) ◽  
pp. 68-72 ◽  
Author(s):  
S. Lundqvist ◽  
S. O. Hietala ◽  
S. Groth ◽  
J. G. Sjödin
Keyword(s):  
Plasma Sample ◽  
Fluorescence Analysis ◽  
Single Sample ◽  
Total Plasma ◽  
Total Plasma Clearance ◽  
X Ray ◽  
Multiple Sample ◽  
Single Plasma ◽  
Selection Of

Purpose: To derive new formulae for the calculation of single sample clearance of the contrast medium iohexol and to compare the formulae to a selection of existing single sample clearance formulae derived for the calculation of 51Cr-EDTA and 99mTc-DTPA clearance. Material and Methods: Glomerular filtration rate (GFR) was calculated from total plasma clearance of iohexol used for urography in 902 patients. Two plasma samples were drawn in each patient. Automated x-ray fluorescence analysis equipment was used for the plasma iodine analysis. Single and multiple sample iohexol clearance values were compared. In 77 patients the multiple sample clearance values were additionally compared to a 51Cr-EDTA clearance performed simultaneously or within 14 days. Results: The precision of the results calculated by the existing single sample clearance formulae and the derived iohexol single sample clearance formulae were essentially the same. The most precise of the derived formulae was that based on the Bak Christensen & Groth formula. The correlation between multiple sample clearance of iohexol and 51Cr-EDTA was high (r=0.918) Conclusion: Iohexol can substitute 51Cr-EDTA for GFR measurement. A valid GFR can be calculated from a single plasma sample determination of iohexol clearance using either the existing formulae or the new formulae derived from the present study.

Simultaneous Urography and Determination of Glomerular Filtration Rate

1994 ◽  
Vol 35 (4) ◽  
pp. 391-395 ◽  
Author(s):  
S. Lundqvist ◽  
S.-O. Hietala ◽  
C. Berglund ◽  
K. Karp
Keyword(s):  
Contrast Medium ◽  
Filtration Rate ◽  
Plasma Clearance ◽  
Patient Comfort ◽  
Total Plasma ◽  
Total Plasma Clearance ◽  
X Ray ◽  
Multiple Sample ◽  
Fluorescence Analyzer

The total plasma clearance of iohexol at urography and 51Cr-EDTA was compared in 31 patients with di- or tetraparesis. A reference 51Cr-EDTA clearance was also performed 24 hours prior to the urography. The GFR was calculated from one, 2 or 4 plasma samples collected 180, 210, 240 and 270 min after the injection. An X-ray fluorescence analyzer was used for the analysis of iohexol in plasma as well as the contrast medium clearance calculations. It was shown that single or multiple sample clearance of iohexol and 51Cr-EDTA were equivalent methods for measurement of the GFR. The GFR was not affected by iohexol in a dose routinely used for urography. It was concluded that the patient comfort is improved if 51Cr-EDTA clearance is replaced by contrast medium clearance in association with urography.

Use of X-ray Fluorescence Analysis for the Determination of Rare Earth Elements

2016 ◽  
Vol 1 (9) ◽  
Author(s):  
Rainer Schramm
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Fluorescence Analysis ◽  
Solid Material ◽  
Spectral Lines ◽  
Energy Dispersive ◽  
X Ray ◽  
Reference Samples ◽  
Selection Of

AbstractX-ray fluorescence spectrometry (XRF) is a powerful tool for the analysis of solid material. That is the reason why the technique was applied for the determination of rare earth elements (REEs) since about 1970. At present, energy-dispersive XRF and wavelength-dispersive XRF are used for the analysis of pressed powder pellets or fused Li-borate beads containing REEs. The production of reliable results can only be achieved by careful optimization of the parameter, in particular the selection of spectral lines. The quantification is based on a calibration realized by using reference samples.

Glomerular Filtration Rate Estimated after Multiple Injections of Contrast Medium during Angiography

1988 ◽  
Vol 29 (6) ◽  
pp. 669-674 ◽  
Author(s):  
M. Boijsen ◽  
G. Granerus ◽  
L. Jacobsson ◽  
L. Björneld ◽  
M. Aurell ◽  
...  
Keyword(s):  
Renal Failure ◽  
Contrast Medium ◽  
Filtration Rate ◽  
Plasma Clearance ◽  
Single Injection ◽  
Fluorescence Analysis ◽  
Total Plasma ◽  
Total Plasma Clearance ◽  
X Ray ◽  
Multiple Injections

In twenty-six patients referred for angiography, clearance of contrast medium was determined with x-ray fluorescence analysis after multiple injections of contrast medium. A formula for correction of the injected amount, which takes into consideration the different times of contrast medium injections, approximating the total injected amount into one injection, was used. A single injection clearance of 51Cr-EDTA was determined at the same time. The results showed a good correlation between the clearance of contrast medium after multiple injections and the 51Cr-EDTA clearance after a single injection (r=0.945). The correlation between contrast medium clearance calculated without correction for the different injection times, and “Cr-EDTA clearance was the same (r=0.946), due to short angiography time and rather low clearance values in our patients. It is concluded that total plasma clearance of contrast medium can easily be estimated after multiple injections. In this way patients with a risk of developing post-angiographic renal failure can be found.

Renal Function Measured by X-ray Fluorescence Analysis

1987 ◽  
Vol 28 (5) ◽  
pp. 581-585 ◽  
Author(s):  
M. Boijsen ◽  
L. Jacobsson ◽  
U. Tylén
Keyword(s):  
Contrast Medium ◽  
Plasma Clearance ◽  
Total Error ◽  
Fluorescence Analysis ◽  
Iodine Concentration ◽  
Total Plasma ◽  
Total Plasma Clearance ◽  
Transient Change ◽  
X Ray ◽  
Medium Dose

In twenty-six patients injected with metrizoate during urography, plasma was analyzed for iodine concentration using x-ray fluorescence analysis, and total plasma clearance of contrast medium was calculated. Total plasma clearance of 51Cr-EDTA was also determined, but not simultaneously, in order to find out if the urographic procedure would influence the kidneys to such an extent that the contrast medium clearance value would differ much from the 51Cr-EDTA clearance value. The errors in the method were assessed and the total error of the contrast medium clearance determination was calculated. When comparing 51Cr-EDTA and metrizoate clearance a correlation of 0.94 and a mean ratio of 1.046 (SD 0.138) was found. The assessable errors cannot fully explain the standard deviation, which might indicate a transient change in kidney function related to elements of the urographic procedure such as laxation with possible dehydration and/or the contrast medium dose.

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.

Determination of the composition of binary chalcogenide glasses by X-ray fluorescence analysis

2010 ◽  
Vol 44 (1) ◽  
pp. 24-27 ◽  
Author(s):  
G. A. Bordovsky ◽  
A. V. Marchenko ◽  
P. P. Seregin ◽  
N. N. Smirnova ◽  
E. I. Terukov
Keyword(s):  
Chalcogenide Glasses ◽  
Fluorescence Analysis ◽  
X Ray
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