Quality assessment internal measures

Quality control describes the measures used to ensure the quality of individual results or a batch of results. The measures used will vary according to the particular application. It is a means of evaluating the current performance of the method being used and the general procedures used in the laboratory. There are two types of quality control, namely internal quality control and external quality assessment. These are covered in detail in Chapters 6 and 7, respectively. 

Abstract By the definition of the mole as a base unit for amount-of-substance measures within the International System of Units (SI), chemists can make chemical measurements in full compliance with established metrological principles. Since the mole requires exact knowledge of the chemical entity, which is often neither available nor of practical relevance to the purpose of the measurement, the SI units of mass or length (for volume) are unavoidable in the expression of results of many chemical measurements. Science, technology, and trade depend upon a huge and ever increasing number and variety of chemical determinations to quantify material composition and quality. Thus, international harmonization in the assessments of processes, procedures, and results is highly desirable and clearly cost effective. The authors, with relevant experience and re-... 

Table 3 Acceptance limits set by external quality assessment (EQA) organizers for inorganic components in human serum based on biological variations and the potential of routine methods and observed ranges in the International Measurement Evaluation Programme (IMEP)-7 Evaluation Programme [5]...

For non-SI traceable quantities the predominant objective must be an agreement on the definition of these quantities on an international basis before reference measurement procedures can be developed and used for assigning target values in external quality assessment. 

Multi-component hydrocarbon standards to provide accurate calibration of instruments (generally gas chromatographs) used to monitor the concentrations of a wide range of volatile organic hydrocarbon compounds (VOCs) in ambient air. These standards currently contain 30 different hydrocarbon species that are important to photochemical ozone formation, with concentrations ranging down to a few parts per billion by molar value. They are disseminated widely in the United Kingdom and the rest of Europe as calibration standards, and as test mixtures for assessment of the quality of international ambient hydrocarbon measurements (often under the auspices of the European Commission - EC). 

A great failure routinely exhibited by many internal audit programs is the lack of an internal rating system. The results of every audit should receive a rating, and each audit should be measured against the previous audit(s) in an effort to determine whether or not the firm is making the necessary improvements. Evidence of continued digression or lack of any improvement audit to audit would serve as a very useful quality indicator and real-time alert mechanism for QA to use as part of its product quality assessment and future release decisions. 

Communautaire. Accreditation aims at the reliability of measurement results and enables laboratories to demonstrate technical competence to their customers. Metrological concepts in food science have become a widely discussed topic over the last few years. Representing the top of the international measurement infrastructure, the National Metrology Institutes (NMIs) have the mandate to disseminate the best practice and measurement capabilities to the beld laboratories (FLs) in their countries. The European and international measurement infrastructure needs high-quality tools to assess the reliability and comparability of measurements results in view of the implementation of EU and international policies regarding internal market activities as well as health and consumer protection issues. 

IMEP cannot be understood as solely an ILC or a PT scheme. It is the core of a whole process that enables the assessment of measurement performance throughout the international measurement infrastructure on the basis of high-quality reference measurements. Samples from the same batch are used in parallel to the execution of an IMEP comparison for ILCs to demonstrate equivalence of measurement results on an international, European, or regional level. The organization of all these comparisons in parallel on one sample material needs to be aligned in a strict time planning in order to avoid any exchange of the possible reference value between the participants. 

By using the same sample material for the different ILCs, the quality of carrying out the same analysis can be compared throughout the European and international measurement infrastructure. Therefore, with the IMEP process the equivalent implementation of directives and regulations can be assessed across an enlarged EU. 

Calibration should include points of higher and lower concentrations than the sample, and quality assessment samples should be included at appropriate concentrations in frequently run assays. Peak measurement may be by peak height or by the peak area obtained by integration. The plot of the ratio of peak height (or area) of the drug to internal standard versus concentration will be a straight line with most detectors. 

Fig. 1.3, The quality spiral described in Fig. 1,1 and its implementation depend on the tools available in the laboratory. These tools concern laboratory structure, personnel, management, external and internal quality assessment measures. The proper use of the available tools will lead to the development of the quality objectives (adapted from ref [10]).

QA (the activities and functions concerned with the attainment of quality). This can take into account the establishment of GLP in the laboratory environment (of research as well as QC), as well as GMP in the production environment. It is concerned with the manufacturing facilities, together with the systems, procedures and disciplines that guarantee that manufacture is right first time. It is equally concerned with the operation of the internal quality assessment systems, which should include efficient self-checking by production of the production process as well as the independent measurement of quality conformance by QC. 

An international quality-assessment program for measurement of aluminum in human plasma a progress report. Clin Chem 34 1603 — 1604. 

Depending on the chosen approach (see Section 3.1) service quality can be measured from the customer s and the service provider s point of view. Measuring from the service provider s point of view involves gathering data that are internally available, such as performance measures or quality cost (Eversheim 1997). They can be analyzed using well-known methods from quality management in manufacturing processes, such as statistical process control (Gogoll 1996). In addition, service quality can be assessed indirectly by an overall analysis of the quality system, which is done by a... 

The purpose of all of these techniques is to determine how a system performs based on the selection of one or more performance parameters. The first two techniques on repetitive measurement and the use of internal test or reference samples is the classical way to evaluate precision. However this can be a time consuming process if it is not carefully planned, and quality assessment frequently provides a way to minimize the number of measurements. The use of duplicate samples in routine testing, and the accumulation of this information over a time period, is another approach to evaluating precision. More details on this will be given in Section 8 on laboratory precision, which addresses both intralaboratory and interlaboratory operations. 

External quality assessment Many countries have authoritative, regular, structured provision for EQA for at least general clinical laboratory work (biochemistry, hematology, microbiology). There are also large numbers of specialist EQA schemes, often international, for those analytes measured in fewer laboratories. In addition, schemes to monitor... 

In the previous chapter, it was established that in industry, plant hazards can cause harm to property (plant—machinery, asset), people, or the environment. So, it is important to develop some means of analyzing these and come up with a solution. Unfortunately, it is not as straightforward as it sounds. There are plenty of plant hazard analysis (PHA) techniques and each of them has certain strengths and weaknesses. Also each specific plant and associated hazard has specific requirements to be matched so that hazard analysis will be effective. In this chapter, various hazards (in generic terms) will be examined to judge their importance, conditions, quality, etc. so that out of so many techniques available for PHA it is possible to select which one is better (not the best because that needs to be done by experts specifically for the concerned plant) suited for the type of plant. So, discussion will be more toward evaluation of PHA techniques. Some PHA is more suited for process safety management (PSM) and is sometimes more applicable for internal fault effects [e.g., hazard and operability study (HAZOP)]. In contrast, hazard identification (HAZID) is applicable for other plants, especially for the identification of external effects and maj or incidents. HAZID is also covered in this chapter. As a continuation of the same discussion, it will be better to look at various aspects of risk analysis with preliminary ideas already developed in the previous chapter. In risk analysis risk assessment, control measures for safety management systems (SMSs) will be discussed to complete the topic. 

Over the past decade, a major trend has been the development of the use of proficiency testing (PT) or evaluation materials (Fox 2000). PT materials are a type of reference material, which aid in assessment of analytical laboratory measurement quality. There will be an increased use of such materials as part of laboratory accreditation programs and other new quality assurance efforts, including internal audits. At the same time, a number of providers have used PT schemes to produce a form of RM intended to meet the ever-growing need for RMs required for routine QC use (Jenks 1995,1997). 

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