The provision of simple analysis results, without any information on their quality and traceability, is no longer considered satisfactory. Today, laboratories must demonstrate the reliability of their measurements and, more generally, of their "analytical system".
They implement what is known as quality control of results. This control covers all the measures taken by the laboratory to ensure that the results produced are suitable for their intended use.
We distinguish 2 types of quality control:
external quality control, which consists of taking part in inter-laboratory comparisons,
internal quality control, which corresponds to intra-laboratory monitoring of results using a control chart. It can easily be carried out with the use of our TITRIVIN.
External quality control
External quality control is defined as "A process using, for quality control purposes, the results of several laboratories analyzing the same sample".
During inter-laboratory comparisons, the same sample is analyzed by all participants. Statistical processing by the organizer makes it possible to obtain, for a given parameter, an assigned value that participants will take as a "reference".
Each laboratory will then compare the result it has obtained with this reference. To do this, the laboratory calculates a trueness index called Z-score.
The advantage of this Z-score is that it is:
interpretable in a direct way,
invariable from one test to another,
without scale.
It therefore enables us to compare all the results obtained during these inter-laboratory tests. This index must be monitored over time to detect any drifts or problems. It is therefore advisable to set up a Z-score control chart.
This type of quality control enables us above all to show that the laboratory is delivering results comparable to those of other laboratories. It is one way of verifying the accuracy of the laboratory's results.
Internal quality control
Internal quality control is defined as: "A process using, for quality control purposes, the results of a single laboratory".
Its main objective is to enable the laboratory to technically validate a series of measurements. By analyzing the same sample (control sample) at regular intervals, the laboratory ensures that its series has the same specifications as usual.
It also has the function of verifying the stability of the analysis system (or method).
The main and essential tool for this monitoring is the control chart.
The implementation of this monitoring is made easier by the use of our TITRIVIN, as they provide laboratories with a control sample that is:
reliable and stable over time,
convenient and easy to use (in 10 mL ampoules).
Furthermore, the TITRIVIN range covers all wine analyses for the main parameters.
When you use a TITRIVIN to produce your control chart, you demonstrate the fidelity and accuracy of your results thanks to its interpretation. In fact, you can rely on reference values obtained from the results of some forty laboratories.