Analytical quality control
Encyclopedia
Analytical quality control, commonly shortened to AQC refers to all those processes and procedures designed to ensure that the results of laboratory
analysis
are consistent, comparable, accurate and within specified limits of precision
.
AQC processes are of particular importance in Laboratories analysing environmental samples where the concentration of chemical species present may be extremely low and close to the detection limit of the analytical method. Very low concentrations of potentially harmful materials in a very large flow of a major river can equate to a considerable environmental load even at concentrations in the parts per billion range.
In well managed laboratories, AQC processes are built into the routine operations of the laboratory often by the random introduction of known standards in to the sample stream or by the use of spiked samples.
in the UK
, AQC can also be applied to validate one laboratory against another. In such cases the work may be referred to as inter laboratory calibration.
Laboratory
A laboratory is a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories...
analysis
Analysis
Analysis is the process of breaking a complex topic or substance into smaller parts to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle , though analysis as a formal concept is a relatively recent development.The word is...
are consistent, comparable, accurate and within specified limits of precision
Precision
Concepts* Accuracy and precision, measurement deviation from true value and its scatter* Precision , the number of digits from which a value is expressed* Precision , the percentage of documents returned that are relevant...
.
AQC processes are of particular importance in Laboratories analysing environmental samples where the concentration of chemical species present may be extremely low and close to the detection limit of the analytical method. Very low concentrations of potentially harmful materials in a very large flow of a major river can equate to a considerable environmental load even at concentrations in the parts per billion range.
In well managed laboratories, AQC processes are built into the routine operations of the laboratory often by the random introduction of known standards in to the sample stream or by the use of spiked samples.
Statistics
Because of the complex inter-relationship between analytical method, sample concentration, limits of detection and method precision, the management of AQC is undertaken using a statistical approach to determine whether the results obtained lie within an acceptable statistical envelope.Inter laboratory calibration
In circumstances where more than laboratory are analysing samples and feeding data into a large programme of work such as the Harmonised monitoring schemeHarmonised monitoring scheme
The Harmonised monitoring scheme is a long term river water quality monitoring scheme in the United Kingdom. The term is also used to refer to the long term data sets produced by the scheme.-Establishment:...
in the UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, AQC can also be applied to validate one laboratory against another. In such cases the work may be referred to as inter laboratory calibration.