The elimination of matrix effects in the determination of fluorine by proton induced prompt gamma-spectrometry

1991 ◽  
Vol 151 (1) ◽  
pp. 63-73 ◽  
Author(s):  
C. Olivier ◽  
H. J. Morland
Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3101
Author(s):  
Mariana N. Oliveira ◽  
Oriana C. Gonçalves ◽  
Samir M. Ahmad ◽  
Jaderson K. Schneider ◽  
Laiza C. Krause ◽  
...  

This work entailed the development, optimization, validation, and application of a novel analytical approach, using the bar adsorptive microextraction technique (BAμE), for the determination of the six most common tricyclic antidepressants (TCAs; amitriptyline, mianserin, trimipramine, imipramine, mirtazapine and dosulepin) in urine matrices. To achieve this goal, we employed, for the first time, new generation microextraction devices coated with convenient sorbent phases, polymers and novel activated carbons prepared from biomaterial waste, in combination with large-volume-injection gas chromatography-mass spectrometry operating in selected-ion monitoring mode (LVI-GC-MS(SIM)). Preliminary assays on sorbent coatings, showed that the polymeric phases present a much more effective performance, as the tested biosorbents exhibited low efficiency for application in microextraction techniques. By using BAμE coated with C18 polymer, under optimized experimental conditions, the detection limits achieved for the six TCAs ranged from 0.2 to 1.6 μg L−1 and, weighted linear regressions resulted in remarkable linearity (r2 > 0.9960) between 10.0 and 1000.0 μg L−1. The developed analytical methodology (BAμE(C18)/LVI-GC-MS(SIM)) provided suitable matrix effects (90.2–112.9%, RSD ≤ 13.9%), high recovery yields (92.3–111.5%, RSD ≤ 12.3%) and a remarkable overall process efficiency (ranging from 84.9% to 124.3%, RSD ≤ 13.9%). The developed and validated methodology was successfully applied for screening the six TCAs in real urine matrices. The proposed analytical methodology proved to be an eco-user-friendly approach to monitor trace levels of TCAs in complex urine matrices and an outstanding analytical alternative in comparison with other microextraction-based techniques.


2012 ◽  
Vol 10 (3) ◽  
pp. 876-899 ◽  
Author(s):  
Ednei Primel ◽  
Sergiane Caldas ◽  
Ana Escarrone

AbstractResidues of pesticides, pharmaceutical and personal care products (PPCPs) are contaminants of world-wide concern. Consequently, there is a growing need to develop reliable analytical methods, which enable rapid, sensitive and selective determination of these pollutants in environmental samples, at trace levels. In this paper, a review of the liquid chromatography-tandem mass spectrometry (LC-MS/MS) based methods for the determination of pesticides and PPCPs in the environment is presented. Advanced aspects of current LC-MS/MS methodology, including sample preparation and matrix effects, are discussed.


1992 ◽  
Vol 46 (9) ◽  
pp. 1382-1387 ◽  
Author(s):  
J. A. Aguilera ◽  
C. Aragón ◽  
J. Campos

Laser-induced breakdown spectroscopy has been used to determine carbon content in steel. The plasma was formed by focusing a Nd:YAG laser on the sample surface. With the use of time-resolved spectroscopy and generation of the plasma in nitrogen atmosphere, a precision of 1.6% and a detection limit of 65 ppm have been obtained. These values are similar to those of other accurate conventional techniques. Matrix effects for the studied steels are reduced to a small slope difference between the calibration curves for stainless and nonstainless steels.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 582
Author(s):  
Julius Sundermann ◽  
Steffen Sydow ◽  
Laura Burmeister ◽  
Andrea Hoffmann ◽  
Henning Menzel ◽  
...  

Chitosan nanogel-coated polycaprolactone (PCL) fiber mat-based implant prototypes with tailored release of bone morphogenic protein 2 (BMP-2) are a promising approach to achieve implant-mediated bone regeneration. In order to ensure reliable in vitro release results, the robustness of a commercially available ELISA for E. coli-derived BMP-2 and the parallel determination of BMP-2 recovery using a quantitative biological activity assay were investigated within a common release setup, with special reference to solubility and matrix effects. Without bovine serum albumin and Tween 20 as solubilizing additives to release media buffed at physiological pH, BMP‑2 recoveries after release were notably reduced. In contrast, the addition of chitosan to release samples caused an excessive recovery. A possible explanation for these effects is the reversible aggregation tendency of BMP-2, which might be influenced by an interaction with chitosan. The interfering effects highlighted in this study are of great importance for bio-assay-based BMP-2 quantification, especially in the context of pharmaceutical release experiments.


2005 ◽  
Vol 48 (spe2) ◽  
pp. 221-228 ◽  
Author(s):  
José Araújo dos Santos Júnior ◽  
Jorge João Ricardo Ferreira Cardoso ◽  
Cleomacio Miguel da Silva ◽  
Suêldo Vita Silveira ◽  
Romilton dos Santos Amaral

Potassium-40 was determined in soil in an area with 40,000 m² situated in the western State of Pernambuco, Brazil. For radiometric measurements, the gamma spectrometry method with a high purity germanium (HPGe) detector was used. Sampling of 78 soil samples has been performed at intervals of 25 m. The specific activities of 40K were calculated based on the photopeak of 1.46 MeV. Values from 541 to 3,572 Bq kg-1 were obtained (mean of 1,827 Bq kg-1). These values allowed the determination of the elemental concentrations as well as the absorbed dose rates in air, 1 m above the ground. The values varied from 1.7 to 11.5% (mean of 6%) and from 23.4 to 154.3 nGy h-1 (mean of 79 nGy h-1), respectively.


2009 ◽  
Vol 385 (1) ◽  
pp. 131-133 ◽  
Author(s):  
Chhavi Agarwal ◽  
Sanhita Poi ◽  
T.N. Nathaniel ◽  
Amol Mhatre ◽  
P.C. Kalsi ◽  
...  

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