scholarly journals Reference materials for optic nanosensor systems: reduced glutathione and chloramphenicol

2021 ◽  
Vol 17 (1) ◽  
pp. 59-69
Author(s):  
A. A. Yushina ◽  
M. K. Alenichev
Keyword(s):  
Light Scattering ◽  
Reference Material ◽  
Dynamic Light Scattering ◽  
Reference Materials ◽  
Reduced Glutathione ◽  
Point Of Care ◽  
Sampling Site ◽  
Coverage Factor ◽  
Expanded Uncertainty ◽  
Certified Value

The research provides enterprise reference material (ERM) development approach for nanosensor system on the basis of dynamic light scattering and fluorescence for qualitative and quantitative determination of nutrition pollutant - chloramphenicol antibiotic (laevomycetin), as well as marker of ischaemic stroke and a number of other diseases - reduced glutathione.ERM candidate materials were chosen chloramphenicol and reduced glutathione. The attestation procedure based on calculating-experimental approach by preparation procedure was used to determine the certified value of ERM. During the tests there were determined metrological characteristics of reference material. The certified value of ERM for reduced glutathione mass fraction is 98,5 %, the expanded uncertainty of certified value with coverage factor k=2 is ± 0,3 %. The certified value of ERM for chloramphenicol mass concentration is 10,0 g/dm3, the expanded uncertainty of certified value with coverage factor k = 2 is ± 4,0 %.The implementation of the developed ERMs showed their appropriateness for optic nanosensor systems calibration on the base of dynamic light scattering and fluorescence.We suppose that the developed enterprise reference materials further may be certified as CRM (certified reference material) and used for verification, calibration and graduation of compact detection devices of the «point of care diagnostics» type under development, which are intended for express analysis on the sampling site directly.

scholarly journals The problem of improving the quality of seriously issued certified reference materials of the composition of gas mixtures

2019 ◽  
Vol 15 (3) ◽  
pp. 5-13
Author(s):  
L. A. Konopelko ◽  
A. V. Kolobova ◽  
O. V. Fatina
Keyword(s):  
Reference Material ◽  
Reference Materials ◽  
Certified Reference Materials ◽  
Metrological Traceability ◽  
Gas Mixtures ◽  
Measuring Instruments ◽  
Expanded Uncertainty ◽  
Iso Guide 35 ◽  
The Russian Federation

Currently, in the Russian Federation, the metrological traceability of certified reference materials of the composition of gas mixtures in cylinders under pressure produced by manufacturers of certified reference materials is carried out in accordance with GOST 8.578-2014. Considering that certified reference materials of the composition of gas mixtures in cylinders under pressure are used for testing to approye the type of measuring instruments, verification, calibration, and graduation of gas-analytical measuring instruments used to control explosive gases and vapors, harmful components in the atmospheric air and the air of the working area, emissions from vehicles and enterprises, to control technological processes, the quality of hydrocarbon products, etc., the issue of ensuring the quality of seriously produced certified reference materials (about 100.000 cylinders with gas mixtures per year) is important. To ensure the quality of certified reference materials of gas mixtures in cylinders under pressure, mass-produced by manufacturers of certified reference materials, we offer the following actions:– manufacturers of certified reference materials’ passing of mandatory accreditation for compliance with the requirements of GOST ISO Guide 34–2014 and GOST ISO Guide 35–2015;– manufacturers of certified reference materials’ constant participation in the proficiency testing programs through interlaboratory tests;– actualizing and refining the existing set of standards defining the requirements for the entire life cycle of a certified reference material of a gas mixture in a cylinder under pressure;– improving the method of certification of a reference material by calculating the value of the expanded uncertainty of the reference material and the introducting a new coefficient «technological reserve».

scholarly journals IAPSO Standard Seawater: Definition of the Uncertainty in the Calibration Procedure, and Stability of Recent Batches

2007 ◽  
Vol 24 (10) ◽  
pp. 1785-1799 ◽  
Author(s):  
Sheldon Bacon ◽  
Fred Culkin ◽  
Nigel Higgs ◽  
Paul Ridout
Keyword(s):  
Reference Material ◽  
Potassium Chloride ◽  
Manufacturing Process ◽  
Calibration Procedure ◽  
Conductivity Ratio ◽  
Coverage Factor ◽  
Expanded Uncertainty ◽  
Significant Variability ◽  
Definition Of

Abstract Standard seawater (SSW) has been employed by oceanographers as a reference material in the determination of salinity for over a century. In all that time, this is the first study to determine the uncertainty of the SSW manufacturing process. SSW is calibrated in reference to carefully prepared solutions of potassium chloride (KCl). All uncertainties in the preparation and measurement of KCl solutions and of new SSW are calculated. The expanded uncertainty of the SSW conductivity ratio is found to be 1 × 10−5, based on a coverage factor of 2, at the time of manufacture. There is no discernible “within batch” variability. No significant variability of quality within or between batches of KCl is found. Measurement of SSW “offsets” from the label conductivity ratio as long as 5 yr after the SSW batch manufacture are reported, and no significant change in label conductivity ratio for SSW batches P130 through P144 outside the expanded uncertainty of 1 × 10−5 is found. This last result is in contrast to some other studies, and herein are suggestions as to why this may be the case.

A Colloidal Silica Reference Material for Nanoparticle Sizing by Means of Dynamic Light Scattering and Centrifugal Liquid Sedimentation

2010 ◽  
Vol 27 (3-4) ◽  
pp. 112-124 ◽  
Author(s):  
Olivier Couteau ◽  
Jean Charoud-Got ◽  
Hubert Rauscher ◽  
Fabio Franchini ◽  
François Rossi ◽  
...  
Keyword(s):  
Light Scattering ◽  
Reference Material ◽  
Dynamic Light Scattering ◽  
Colloidal Silica

Development of Milk Powder Reference Materials Certified for Aflatoxin Mt Content (Part II): Certification of Milk Powder RM 283

1988 ◽  
Vol 71 (6) ◽  
pp. 1180-1182
Author(s):  
Hans P Van Egmond ◽  
Peter J Wagstaffe
Keyword(s):  
Reference Material ◽  
Reference Materials ◽  
Milk Powder ◽  
Term Study ◽  
Target Concentration ◽  
Long Term Study ◽  
Certified Value ◽  
Replicate Measurements ◽  
Calibration Control

Abstract The development of a full cream milk powder reference material, certified for its aflatoxin M, content (target concentration: 0.1 fig/ kg), is described. The material (RM 283) was prepared and certified within the Reference Material Programme of the Community Bureau of Reference, along with other members of a series of milk powder reference materials. Homogeneity, evaluated by determining the aflatoxin M, content of 30 units, was found to be acceptable (coefficient of variation of analysis results: 9.1%); stability has been demonstrated in a long-term study. The certification exercise involved 7 laboratories. Calibration, control of recoveries, blank values, and independence of the replicate measurements were emphasized. All sets of results of the certification exercise were accepted for statistical evaluation. A certified value for the aflatoxin M, content: 0.09(+0.04)(-0.02) Mg/kg was derived. The certification of RM 283 completes the series of 4 milk powder reference materials having certified aflatoxin M, contents

scholarly journals Ultrasensitive dynamic light scattering immunosensing platform for NT-proBNP detection using boronate affinity amplification

2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Jiaqi Hu ◽  
Lu Ding ◽  
Jing Chen ◽  
Jinhua Fu ◽  
Kang Zhu ◽  
...  
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Phenylboronic Acid ◽  
Crosslinking Agent ◽  
Fast Response ◽  
Small Sample ◽  
Complex Samples ◽  
Promising Application

AbstractHerein, we reported a new dynamic light scattering (DLS) immunosensing technology for the rapid and sensitive detection of glycoprotein N-terminal pro-brain natriuretic peptide (NT-proBNP). In this design, the boronate affinity recognition based on the interaction of boronic acid ligands and cis-diols was introduced to amplify the nanoparticle aggregation to enable highly sensitive DLS transduction, thereby lowering the limit of detection (LOD) of the methodology. After covalently coupling with antibodies, magnetic nanoparticles (MNPs) were employed as the nanoprobes to selectively capture trace amount of NT-proBNP from complex samples and facilitate DLS signal transduction. Meanwhile, silica nanoparticles modified with phenylboronic acid (SiO2@PBA) were designed as the crosslinking agent to bridge the aggregation of MNPs in the presence of target NT-proBNP. Owing to the multivalent and fast affinity recognition between NT-proBNP containing cis-diols and SiO2@PBA, the developed DLS immunosensor exhibited charming advantages over traditional immunoassays, including ultrahigh sensitivity with an LOD of 7.4 fg mL−1, fast response time (< 20 min), and small sample consumption (1 μL). The DLS immunosensor was further characterized with good selectivity, accuracy, precision, reproducibility, and practicability. Collectively, this work demonstrated the promising application of the designed boronate affinity amplified-DLS immunosensor for field or point-of-care testing of cis-diol-containing molecules. Graphical Abstract

Dynamic light scattering from gels in a poor solvent

1978 ◽  
Vol 39 (9) ◽  
pp. 955-960 ◽  
Author(s):  
E. Geissler ◽  
A.M. Hecht
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Poor Solvent
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