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Introduction

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.

In practice, fitness for purpose is determined by a comparison of the accuracy achieved in a laboratory at a given time with a required level of accuracy therefore it comprises the routine practical procedures that enable the analytical chemist to accept a result or group of results as fit for purpose, or reject the results and repeat the analysis.

So QC is an important determinant of the quality of analytical data, and is recognized as such by accreditation agencies.

Internal quality control is undertaken by the inclusion of particular reference materials, here called "control materials", into the analytical sequence and by duplicate analysis. The control materials should, be representative https://www.51lunwen.org/englishpaper/ 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.

Quality control is a final check of the correct execution of all of the procedures that are prescribed in the analytical protocol and all of the other quality assurance measures that underlie good analytical practice. QC also required being as far as possible independent of the analytical protocol, especially the calibration, that it is designed to test.

Ideally both the control materials and those used to create the calibration should be traceable to appropriate certified reference materials or a recognized empirical reference method. When this is not possible, control materials should be traceable at least to a material of guaranteed purity or other well characterized material.

In a typical analytical situation several, similar test materials will be analysed together, and control materials will be included in the group. Often determinations will be duplicated by the analysis of separate test portions of the same material. Such a group of materials regarded as being analyzed under effectively constant conditions. The batches of reagents, the instrument settings, the analyst, and the laboratory environment will under ideal control as no unchanged occur during analysis.

Systematic errors should therefore remain constant during the experiment as the monitoring of these errors is of concern.

The control materials are the basic unit of QC which regarded as being carried out under repeatability conditions.

For example, reagents may degrade, instruments may drift, minor adjustments to instrumental settings may be called for, or the laboratory temperature may rise. However, these systematic effects are subsumed into the repeatability variations.

In few words; to achieve the definition of qualit

y control which is set of procedures undertaken by laboratory staff for the continuous monitoring https://www.51lunwen.org/englishpaper/ of operation and the results of measurements in order to decide whether results are reliable enough to be released, Issues specifically excluded the following:

1.Quality control of sampling. While it is recognized that the quality of the analytical result can be no better than that of the sample,本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。