Sequential flow-injection determination of ionic and total calcium in saliva
S Jun1, J L Lima, M C Montenegro
1Departamento de Química Física, Faculdade de Farmácia, Porto, Portugal.
Journal of Trace Elements and Electrolytes in Health and Disease
|June 1, 1994
Summary
A new flow injection method accurately measures ionic and total calcium in small saliva samples. This technique offers a reliable and direct approach for calcium analysis in clinical settings.
Area of Science:
- Analytical Chemistry
- Biochemistry
- Clinical Diagnostics
Background:
- Accurate calcium determination is crucial for various physiological and pathological conditions.
- Existing methods for saliva calcium analysis can be time-consuming or require larger sample volumes.
Purpose of the Study:
- To develop and validate a novel flow injection manifold for sequential determination of ionic and total calcium in saliva.
- To enable direct analysis of small saliva samples (75 microL) without pre-treatment.
Main Methods:
- Utilized a flow injection manifold with sequential detection.
- Employed a tubular potentiometric detector for ionic calcium and atomic absorption spectrophotometry for total calcium.
- Direct injection of saliva samples without CO2 loss or pre-treatment.
Main Results:
- Achieved good agreement between the flow injection method and reference procedures (direct potentiometry and atomic absorption spectroscopy).
- Paired Student's t-test confirmed no statistical differences in results.
- Demonstrated high precision with relative standard deviations of approximately 3% for ionic calcium and 4% for total calcium.
- Showed negligible effects of coexisting ions, ionic strength, and pH variations.
Conclusions:
- The developed flow injection manifold provides a precise, accurate, and efficient method for sequential determination of ionic and total calcium in saliva.
- This method is suitable for direct analysis of small saliva volumes, offering a valuable tool for clinical diagnostics and research.
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