Chapter 10
Interlaboratory Comparisons
Participation in interlaboratory comparisons allows demonstration of the laboratory’s competences in the scope of conducted tests, supports the process of validation
of analytical procedures, enables the comparison of results obtained in different laboratories, and under specified conditions, allows measurement traceability to be
ensured.
According to the requirement of accreditation, all testing and calibrating laboratories should implement adequate quality control procedures for monitoring the quality
of the reporting results. Those can be performed internally by using reference materials or conduct replicate tests with the same or different analytical procedures. Other
means may focus on the externally organized interlaboratory comparison (ILC) or
proficiency testing (PT), so as to obtain independent evidence regarding the competence of a given laboratory within its scope.
Interlaboratory comparison (ILC): organization, performance and evaluation of
measurements or tests on the same or similar items by two or more laboratories
or inspection bodies in accordance with predetermined conditions.
Clause 3.4; ISO/IEC 17043
Proficiency testing (PT): the evaluation of participant performance against preestablished criteria by means of interlaboratory comparison.
Clause 3.7; ISO/ IEC 17043
The technical competence of the laboratory can be demonstrated by obtaining
successful results in appropriate PT, but is can also be useful for participating in
ILC focusing on broader purposes, for example: (1) to compare the results of two
or more laboratories (ILC); (2) to evaluate the performance of a selected analytical
procedure; and (3) to characterize a reference material.
The results of interlaboratory comparisons are always a valuable source of information for participating laboratories, since they allow an external evaluation of the
© Springer Nature Switzerland AG 2018
E. Bulska, Metrology in Chemistry, Lecture Notes in Chemistry 101,
https://doi.org/10.1007/978-3-319-99206-8_10
171
Interlaboratory Comparisons
Participation in interlaboratory comparisons allows demonstration of the laboratory’s competences in the scope of conducted tests, supports the process of validation
of analytical procedures, enables the comparison of results obtained in different laboratories, and under specified conditions, allows measurement traceability to be
ensured.
According to the requirement of accreditation, all testing and calibrating laboratories should implement adequate quality control procedures for monitoring the quality
of the reporting results. Those can be performed internally by using reference materials or conduct replicate tests with the same or different analytical procedures. Other
means may focus on the externally organized interlaboratory comparison (ILC) or
proficiency testing (PT), so as to obtain independent evidence regarding the competence of a given laboratory within its scope.
Interlaboratory comparison (ILC): organization, performance and evaluation of
measurements or tests on the same or similar items by two or more laboratories
or inspection bodies in accordance with predetermined conditions.
Clause 3.4; ISO/IEC 17043
Proficiency testing (PT): the evaluation of participant performance against preestablished criteria by means of interlaboratory comparison.
Clause 3.7; ISO/ IEC 17043
The technical competence of the laboratory can be demonstrated by obtaining
successful results in appropriate PT, but is can also be useful for participating in
ILC focusing on broader purposes, for example: (1) to compare the results of two
or more laboratories (ILC); (2) to evaluate the performance of a selected analytical
procedure; and (3) to characterize a reference material.
The results of interlaboratory comparisons are always a valuable source of information for participating laboratories, since they allow an external evaluation of the
© Springer Nature Switzerland AG 2018
E. Bulska, Metrology in Chemistry, Lecture Notes in Chemistry 101,
https://doi.org/10.1007/978-3-319-99206-8_10
171