Internal quality control

You could decide to use control charts and to analyse certified reference materials (see chapter 13 and 14). Control charts are a simple, but effective tool for internal quality control. Internal quality control is one of a number of concerted measures that analytical chemists can take to ensure that the data produced in the laboratory are fit for their intended purpose. ... 

The cost of appraisal in a laboratory is about measuring the laboratory performance, morritoring of the laboratory processes, doing internal quality control, internal and external laboratory audits and so on. 

Quality control involves several subjects that must be discussed in connection with dry chemistry. It is the aim of all quality control methods that all results supplied by the clinical laboratory representing a useful estimation of actual data should approximate these actual data as closely as possible and with a low scatter. Quality assurance is subdivided into internal and external quality control. Internal quality control should accompany each series of examinations even if there is only one sample to be examined. In addition, external quality control serves to examine the precision and accuracy of a laboratory as compared to other laboratories. Any external quality control without internal quality control is meaningless. 

Important statistical factors needed to make use of ELISA. Note the links to quality control (internal) and the establishment of confidence in test results. Increasingly, assays need international recognition. 

See alsa Carbohydrates Starch. Derivatization of Analytes. Extraction Solvent Extraction Principles. Fluorescence Food Applications. Gas Chromatography High-Temperature Techniques. Lipids Fatty Acids Polar Lipids. Liquid Chromatography Food Applications. Mass Spectrometry Food Applications. Quality Assurance Quality Control Internal Standards. Sample Handling Comminution of Samples. Sampling Theory. 

See also Quality Assurance Quality Control Internal... 

Due conformity to the cement quality requirements of Dl N1164 (composition and properties) should be verified and monitored by quality control ("internal" control by the cement manufacturer and "external" control by an authorized independent supervisory organization, DIN 1164, Part2). 

BRITISH STANDARDS INST. EUROPEAN ORGANISATION FOR QUALITY CONTROL INTERNATIONAL STANDARDS ORGANISATION... 

The most useful methods for quality assessment are those that are coordinated by the laboratory and that provide the analyst with immediate feedback about the system s state of statistical control. Internal methods of quality assessment included in this section are the analysis of duplicate samples, the analysis of blanks, the analysis of standard samples, and spike recoveries. 

Mondestructive Evaluation and Quality Control, Vol. 17 of Metals Handbook, 9th ed., ASM International, Materials Park, Ohio, 1989. 

Presently efforts of Ukrainian scientists in field of analysis of toxic organic substances directed on harmonization of the developed methods of analysis with the requirements of international standards and on wide introduction in practice of the quality control system in chromatographic researches. 

The method was validated in accordance to the guidelines of the international conference on harmonization (ICH). Data with respect to accuracy, within- and between run precision, recovery, detection and quantitation limits were reported and found to be within the accepted international criteria. Neither endogeneous substances nor the commonly used dmgs were found to interfere with the retention times of the analytes. Standard solutions of the dmg and quality control preparations at high and low level concentrations were demonstrated to be stable at room temperature and/or -20°C for long and short periods of time. 

The analysis was performed by XRF method with SR. SRXRF is an instrumental, multielemental, non-destructive analytical method using synchrotron radiation as primary excitation source. The fluorescence radiation was measured on the XRF beam-line of VEPP-3 (E=2 GeV, 1=100 mA), Institute of Nuclear Physics, Novosibirsk, Russia. For quality control were used international reference standards. 

In addition to fulfilling the in-house requirements for quality control, state and local air monitoring networks which are collecting data for compliance purposes are required to have an external performance audit on an annual basis. Under this program, an independent organization supplies externally calibrated sources of air pollutant gases to be measured by the instrumentation undergoing audit. An audit report summarizes the performance of the instruments. If necessary, further action must be taken to eliminate any major discrepancies between the internal and external calibration results. 

This system assures overall compliance with cGMPs and internal procedures and specifications. The system includes the quality control unit and all of its review and approval duties (e.g. change control, reprocessing, batch release, annual record review, validation protocols, and reports, etc.). It includes all product defect evaluations and evaluation of returned and salvaged drug products. 

High quality is one of the criteria defined in the requirements section above. Since the program should run automatically in batch mode, we mean by quality control an internal check of the 3D structures produced by the structure generator itself. In general, the abilities of a fast, automatic structure builder to assess the quaUty of its models are rather limited since, for example, an exhaustive conformation analysis and energy optimization is impossible in most cases. However, there are a Umited number of simple quaUty checks to avoid trivially distorted structures ... 

References Ihnat (1995), International Atomic Energy Agency and United Nations Environment Programme (1995), National Oceanic and Atmospheric Administration (1995), Analytical Quality Control Services (1998), Quevauviller et al. (1998a), Trahey (1998), European Commission, Joint Research Centre, IRMM (1999). 

Analytical Quality Control Services (1998) AQCS Intercomparison Runs Reference Materials 1998-1999. International Atomic Energy Agency, Vienna. 

It must be remarked that terminology is not consistent and there are many widely used synon)ms. Quality control in this Chapter refers to practices best described as internal quality control. Quahty assessment is often referred to as external quality control, proficiency testing, interlaboratory comparisons, round robins or other terms. Internal Quality Control and External Quality Assessment are preferred because they best describe the objectives for which the RMs are being used, i.e. the immediate and active control of the results being reported from an analytical run or event, and an objective, retrospective assessment of the quality of those results. 

The primary purposes for which reference materials are employed are encompassed within the laboratory Quality Assurance Procedures. Quality assurance comprises a number of management responsibilities which focus on how the laboratory is organized, how it deals with situations, how it interacts with users, together with analytical responsibilities re internal quality control and external quality assessment (Sargent 1995 Burnett 1996). Ideally each component follows a documented protocol and written records of all activities are maintained. 

The inherent reproducibility or imprecision of the method will have been determined as part of the validation procedure. This information can then be applied to the internal quality control programme which is designed to identify the intrusion of a bias (inaccuracy) and/or an alteration in the reproducibility of the assay. Programs for Internal quality control are most extensively developed for clinical laboratories because of the availability of suitable RMs in large batches and at an affordable cost although some level of IQC is appropriate to aU work carried out at a continuing basis see Section 6.2. 

Fig. 4.1 Internal quality control results displayed on a Levis-Jen-nings chart.

To supplement internal quality control within a laboratory. 

Ingamells CO, PiTARD FF (1986) Applied Geochemical Analysis, pp L-84.Wiley, New York. International Federation of Clinical Chemistry (IFCC) (1978) Expert Panel on Nomenclature and Principles of Quality Control in Clinical Chemistry. Clin Chim Acta 83 L89F-202F. International Organization for Standardization (ISO) (1993) Guide to the expression of uncertainty. Geneva. 

Taylor A (1988) The use of internal quality control materials for the preparation and maintenance of reliable methods for measurement of lead in blood. Fresenius Z Anal Chem 332 732-735. 

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