scholarly journals Modern Analytical Facilities 2. A Review of Quality Assurance and Quality Control (QA/QC) Procedures for Lithogeochemical Data

2014 ◽  
Vol 41 (1) ◽  
pp. 75 ◽  
Author(s):  
Stephen J. Piercey

Quality assurance and quality control (QA/QC) are critical components of modern analytical geochemistry.  A properly constructed QA/QC program identifies both the source of analytical error and provides a means of establishing confidence in and assessing limitations of analytical data. A QA/QC program involves monitoring precision, accuracy, and potential contamination from sampling to analysis.  Precision can be monitored via the systematic insertion of sample, pulp, and analytical duplicates, and reference materials; the resulting data are subsequently evaluated using scatterplots, statistical tests (e.g. % relative standard deviation), Thompson-Howarth plots, and the average coefficient of variation (CVavg (%)).  Accuracy is determined through the submission of reference materials and monitored using statistical tests (e.g. % relative difference, t-test) and Shewart control charts.   Blanks test contamination and results are monitored using Shewart control charts.SOMMAIREL'assurance de la qualité et le contrôle de la qualité (AQ-CQ) sont deux composantes essentielles à la géochimie analytique moderne.  Un programme AQ-CQ bien conçu défini à la fois la source de l'erreur d'analyse et un moyen d'établir la confiance et d’évaluer les limites des données analytiques.  Un programme AQ-CQ comprend le contrôle de la précision, de l'exactitude et de la contamination potentielle, de l'étape d’échantillonnage à l'analyse.  La précision peut être contrôlée via l'insertion systématique d'échantillon, de pulpes, et de doublons d'analyse, et de matériaux de référence; les données obtenues sont ensuite évaluées en utilisant des diagrammes de dispersion, des tests statistiques (pourcentage d’écart type relatif, par ex.), des courbes de Thompson-Howarth, et des  coefficients de variation moyens (CVm %).  La précision est déterminée par la soumission de documents de référence et de contrôle par des tests statistiques (différence relative en %, t-test, par ex.) et des graphiques de contrôle de Shewhart.  La contamination d’essais à blanc et les résultats sont contrôlés par des graphiques de contrôle Shewhart.

2001 ◽  
Vol 84 (6) ◽  
pp. 1786-1792 ◽  
Author(s):  
Philippe Quevauviller

Abstract Reference materials represent an invaluable tool for analytical quality control. Certified Reference Materials (CRMs) are used for the validation of methods, whereas various types of (uncertified) Reference Materials (RMs) are used for routine quality control (establishment of control charts) and interlaboratory testing (e.g., proficiency testing). This paper provides background information on the production and use of environmental RMs and describes recent CRMs produced by the BCR (European Commission) for quality assurance in environmental analysis.


Proceedings ◽  
2020 ◽  
Vol 55 (1) ◽  
pp. 2
Author(s):  
Elena Neacsu

The (International Atomic Energy Agency) IAEA’s fundamental safety objective is to protect people and the environment from harmful effects of ionizing radiation. The safety principles apply to all facilities and all activities to reduce existing radiation risks. Analytical quality assurance has gained in importance in many scientific areas, including the analysis of radioactive specimens that require a thorough investigation and regulations for safety and ecological reasons. The use of certified reference materials is an essential pillar for the assessment of the quality of analytical data. Still, such matrix-matched certified reference materials are unfortunately not available for most investigations relevant to the nuclear domain. Therefore, other strategies have to be established, i.e., to compare the analytical results obtained for a particular instrumental technique, with data from another methodology whose analyte detection is based on a different physical principle.


2010 ◽  
Vol 2 (3) ◽  
pp. 135-141
Author(s):  
Narsito Narsito

Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of analytical method, quality assurance in chemical analysis. The assessment of quality parameter for analytical method like the use of standard materials as well as standard methods is given. Concerning with the quality control of analytical data, the use of several techniques, such as control samples and control charts, in monitoring analytical data in quality control program are described qualitatively.  In the final part of this paper, some important remarks for the preparation of collaborative trials, including the evaluation of accuracy and reproducibility of analytical method are also given Keywords: collaborative trials, quality control, analytical data Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of analytical method, quality assurance in chemical analysis. The assessment of quality parameter for analytical method like the use of standard materials as well as standard methods is given. Concerning with the quality control of analytical data, the use of several techniques, such as control samples and control charts, in monitoring analytical data in quality control program are described qualitatively.  In the final part of this paper, some important remarks for the preparation of collaborative trials, including the evaluation of accuracy and reproducibility of analytical method are also given Keywords: collaborative trials, quality control, analytical data


Author(s):  
Ravinder M. Diwan ◽  
Shashikant Shah ◽  
John Eggers

The variability associated with the production, construction, and testing of structural and paving concrete is discussed. Data from more than 900 projects constructed from 1992 through 1999 representing more than 25,000 lots were evaluated. The data were collected from the Louisiana Department of Transportation and Development’s (DOTD’s) computerized Material Test Data Reporting System. The analysis indicated that ( a) overall price reductions were less than 0.2% for structural concrete and about 0.5% for paving concrete, ( b) the thickness of concrete cores is the major contributor to the overall reduction in the price of paving concrete, ( c) there was good control in the production and testing of structural concrete, and ( d) there was an increase in the nonuniformity of paving concrete acceptance criteria. Recommendations include a need to maintain better control of the variability of paving concrete through the application of control charts or unknown variability in the specification types and a need for continued evaluation for monitoring the overall quality control and quality assurance program of the DOTD.


Sign in / Sign up

Export Citation Format

Share Document