System Check and Matrix Check Within the Spectroquant® System
Verifying the product-related functionalities is the most specific and comprehensive step in the process of Analytical Quality Assurance and involves measurement of method-specific standards and real samples. Performance Qualification (PQ) consists of two parts: system check and matrix check. In Merck´s Spectroquant® system it comprises the instrument supported modes AQA 2 and AQA 3.
System check is performed in order to check the entire setup of
In Merck´s Spectroquant® AQA concept this is equivalent with the AQA 2 mode. It is a method-specific check using standard solutions.
Multiparameter standard solutions contained in the various packs are optimally suited for checking the overall system – from the individual test kit and the measurement instrument itself, all the way to your individual working procedures. These standards can also be directly traced back to NIST primary standards. Each CombiCheck pack delivers one standard solution plus one additional solution.
Our range of ready-to-use standard solutions is also at your disposal. Additionally: With Certipur® standard solutions you can prepare standards for almost every parameter in any concentration you wish, simply by making the appropriate dilution.
In connection with Internal Quality Control measures (IQC) pipettes are required to be tested at regular intervals. This check is usually carried out by weighing the volume of a liquid on a calibrated precision balance. Such a scale is, however, not always readily available. With Spectroquant® PipeCheck you can check your pipettes and document the measurement results accordingly, even if you don’t have a balance.
Matrix check is performed in order to identify any measurement errors due to possible interferences from foreign substances within the sample. In Merck´s Spectroquant® AQA concept this is equivalent with the AQA 3 mode.
Under certain circumstances, the interference within the sample can be so great that the recovery of the parameter is significantly less than 100 pecent. For this reason, various foreign substances have been investigated to define the maximum concentration at which they may be present in samples without interfering with the determination. These limits are stated in the package insert of each Spectroquant® test kit. For samples with a very complex or even unknown composition, interferences can be analyzed on the basis of recovery rates and rectified through appropriate countermeasures, such as pre-treating the sample.
Depending on the concentration of the sample, there are two AQA 3 methods to choose from:
1. One-time standard addition (spiking) with CombiCheck R-2 addition solution
2. Multiple dilutions or spiking with self-prepared spiking solutions
To avoid changing the sample matrix, spiking solutions should be highly concentrated standards and used in small quantities relative to the sample portion.
Merck´s portfolio offers you to product ranges you can choose from: