Quality control/assurance States

The written directives of a quality control program are a necessary, but not a sufficient, condition for obtaining and maintaining an analysis in a state of statistical control. Although quality control directives explain how an analysis should be properly conducted, they do not indicate whether the system is under statistical control. This is the role of quality assessment, which is the second component of a quality assurance program. 

These are the characteristics which need to be specified and their achievement controlled, assured, improved, managed, and demonstrated. These are the characteristics which form the subject matter of the specified requirements referred to in ISO 9000. When the value of these characteristics is quantified or qualified they are termed quality requirements or requirements for quality. ISO 8402 1994 defines requirements for quality as an expression of the needs or their translation into a set of quantitatively or qualitatively stated requirements for the characteristics of an entity to enable its realization and examination. While rather verbose, this definition removes the confusion over quality requirements and technical requirements. (An additional definition is provided in Appendix A.) Technical requirements for a product or service are quality requirements. The requirements of ISO 9000 are quality system requirements. 

With the move of many large chemical companies in the United States and abroad becoming more and more global, the need to be able to compare high-quality data between various company locations becomes essential. We have addressed part of this issue, i.e., high temperature GPC data, in three ways. First, we have standardized on one type of GPC column. Second, we have implemented a quality control procedure to make sure that data stay at a high quality. Finally, we have a procedure in place to approve future batches of gel to assure that the chromatograms from batch to batch will be very comparable. 

Support for sites is multi-tiered and includes participation by numerous federal, state, private, academic, and tribal organizations. Network operation includes rigorous field and laboratory quality assurance/quality control (QA/QC), including an external quality assurance program and periodic external on-site audits. 

Suitable quality control and quality assurance procedures should be in place and the analytical system must be in a state of statistical control. 

Internal quality control is undertaken by the inclusion of particular reference materials, called control materials , into the analytical sequence and by duplicate analysis. The control materials should, wherever possible, be representative of the test materials under consideration in respect of matrix composition, the state of physical preparation and the concentration range of the analyte. As the control materials are treated in exactly the same way as the test materials, they are regarded as surrogates that can be used to characterise the performance of the analytical system, both at a specific time and over longer intervals. Internal quality control is a final check of the correct execution of all of the procedures (including calibration) that are prescribed in the analytical protocol and all of the other quality assurance measures that underlie good analytical practice. IQC is therefore necessarily retrospective. It is also required to be as far as possible independent of the analytical protocol, especially the calibration, that it is designed to test. 

Sets of instructions that detail the procedures designed to reduce errors occurring during analytical procedures and ensure accurate quantitations are found in the quality assurance (QA) and quality control (QC) manuals. Quality assurance procedures are used by the laboratory to detect and correct problems in analytical processes. As newer methods and instrumentation are added to the laboratory, older procedures must be modified or changed completely. Quality control procedures are used to maintain a measurement system (i.e., a gas chromatograph) in a statistically satisfactory state to ensure the production of accurate and reliable data. 

Over the last 20 years the reliability of data produced by analytical laboratories has increased dramatically. Strict requirements have ensured that the data were produced under defined standards of quality with a stated level of confidence. The routine day-to-day activities (e.g., matrix fortifications) to control, assess, and ensure the quality of generated data are the quality controls associated with analytical processes. The management of the system that ensures that these processes are in place and functional is the quality assurance portion of the laboratory program to produce reliable data. 

Two elements of quality assurance are quality control and quality assessment. Quality control is a set of measures implemented within an analytical procedure to assure that the process is in control. A combination of these measures constitutes the laboratory QC program. A properly designed and executed QC program will result in a measurement system operating in a state of statistical control, which means that errors have been reduced to acceptable levels. An effective QC program includes the following elements ... 

States National Bureau of Standards Calibration Statistics (NBS), later the National Institute of Standards and Technology (NIST), introduced a measurement quality control concept called measurement assurance, and developed measurement assurance programs, or MAPs, for high-level calibration processes. 

As mentioned earlier, the complete analytical process involves sampling, sample preservation, sample preparation, and finally, analysis. The purpose of quality assurance (QA) and quality control (QC) is to monitor, measure, and keep the systematic and random errors under control. QA/QC measures are necessary during sampling, sample preparation, and analysis. It has been stated that sample preparation is usually the major source of variability in a measurement process. Consequently, the QA/QC during this step is of utmost importance. The discussion here centers on QC during sample preparation. 

Quality assurance (QA) has been described as a system of activities that assures the producer or user of a product that defined standards of quality with a stated level of confidence are met. Quality control (QC) differs in that it is an overall system of activities that controls the quality of a product so that it meets the needs of the users (Taylor, 1987). In other words, QC consists of the technical activities to control and assess the quality of the measurements, while QA is the management system that ensures that an effective QC system is working as planned. 

The application of quality control procedures to ensure that satisfactory analytical performance of enzyme assays is maintained on a day-to-day basis is complicated by the tendency of enzyme preparations to undergo denaturation with loss of activity. This maltes it difficult to distinguish between poor analytical performance and denaturation as possible causes of a low result obtained for a control sample introduced into a batch of analyses. Assured stability within a defined usable time span is therefore the prime requirement for enzyme control materials, as it is for enzyme calibrators. However, specifications for the two types of materials can differ in other respects. Because the function of a calibrator is to provide a stated activity under defined assay conditions, it is not necessary for it to show sensitivity to changes in the assay system identical to those of the samples under test therefore within certain Umits, enzymes from various sources can be considered in the search for stability. However, it is the function of a control to reveal small variations in reaction conditions, so it must mimic the samples being analyzed. The preparation of enzymes from human sources is not by itself a guarantee of an effective control. For example, human placental ALP is very stable, but it differs significantly in kinetic properties from the liver and bone enzymes that contribute most of the ALP activity of human serum samples it is therefore not an ideal enzyme for use in control material for the determination of ALP. 

Under current U.S. federal guidelines, the following records must be retained for at least 2 years for all laboratory testing specimen requisitions, patient test results and reports, instrument printouts, accession records, quality control records, instrument maintenance records, proficiency testing records, and quality improvement records. Laws concerning records for paternity and forensic testing vary by state it is the responsibility of the director to assure all applicable regulations are met. 

Since the early 1980s, there has been a more than fivefold increase in the number of Americans enrolled in HMOs, which has had a dramatic impact on the delivery of healthcare in the United States. As a result of this trend, HMOs realized the need to demonstrate the quality of care they provided to their members compared with fee-for-service health plans however, at the time the industry lacked established standards. Subsequently, various independent review processes evolved, which often did not have consistent assumptions about the parameters that defined quality. It was not until the late 1980s that a group of HMO industry leaders recognized that an organization called the National Committee for Quality Assurance (NCQA) had the potential to act as an independent authority on quality control in managed care. ... 

One of the short-term aims of the quality assurance/quality control (QA/QC) activities of the SWIFT-WFD project was the evaluation of the state-of-the-art of the analytical performances of SMETs in use in Europe, whereas one of the long-term aims was the establishment of a framework of ongoing PT schemes activities supporting the European laboratories involved in the implementation of WFD applying either classical methods or SMETs. 

Medicinal products must be fit for their intended use, comply with the requirements of Market Authorization and not place patients at risk because of inadequate safety, quality or efficacy. These objectives are easy to state, but to achieve them requires a comprehensively designed and correctly implemented system of quality assurance. It is important that this is documented and its effectiveness monitored. Records must be kept that are open to inspection by validating bodies, and there must also be procedures for selfinspection and quality audit that allow appraisal of the quality assurance system. Management must be adequately trained and their responsibilities minutely defined. Two key posts are the Heads of Production and of Quality Control. These posts are required by the guidelines to be independent of one another. 

In 1969, California adopted the Porter-Cologne Act giving the State Water Resources Control Board (State Board) the authority to (1) assure that all water diversions be put to a beneficial use, and (2) maintain and enhance the quality of all waters of the State. One major difference between federal and state water quality protection programs involves protection of ground water. 

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