Development of Suitable ISE Measurement Procedures for SI-Traceable Chemical Activity Determination
In clinical chemistry and medical diagnostics, the reliability of the results obtained by numerous testing protocols has a major impact on the critical decision-making processes. Considerable efforts are made by international institutes to promote and give guidance on measurement comparison...
| Main Authors: | , , |
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| Format: | Article |
| Language: | deu |
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Swiss Chemical Society
2009-10-01
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| Series: | CHIMIA |
| Subjects: | |
| Online Access: | https://www.chimia.ch/chimia/article/view/4735 |
| Summary: | In clinical chemistry and medical diagnostics, the reliability of the results obtained by numerous testing protocols has a major impact on the critical decision-making processes. Considerable efforts are made by international institutes to promote and give guidance on measurement comparisons
and metrological traceability using appropriate certified reference materials. The concentration values or amount of substance contents are usually assigned to chemical analytical results. In contrast, the most relevant quantity is the activity of ions in clinical chemistry. Activity corresponds
to the available biologically active part of these components in a mixture. Many measurement methods and instruments currently in use do not differentiate between the total substance concentration and its biologically active component. In physiological solutions, such as blood plasma, the
chemical activity makes a clear difference between ion or substrate concentration. Ion selective electrodes (ISE) are widely used to directly measure the activity of ions. Measurement by means of ion-selective electrodes is a standard method in point of care testing units (POCT) for continuous
monitoring for e.g. haemodialysis, cardiac surgery and in intensive care units. A metrological approach to ISE potentiometric measurements is proposed, to determine the activity with their uncertainty. A prerequisite is to develop an activity calibration scale for complex electrolyte
solutions with known and traceable ion activities.
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| ISSN: | 0009-4293 2673-2424 |