What is the most common method for measuring sodium levels in the laboratory?

The most common method for measuring sodium levels in the laboratory is the ion-selective electrode (ISE) technique. This method utilizes a special electrode that is sensitive specifically to sodium ions. The ISE generates a potential difference that correlates directly with the concentration of sodium in the sample.

This technique has several advantages, including its ability to provide quick results, ease of use, and relatively low cost compared to other methods. Additionally, ISE can be used on various sample types, including serum, plasma, and urine, making it versatile for clinical settings. Because it is a direct measurement method, it is often preferred for routine sodium testing due to its accuracy and precision in reflecting physiological levels of sodium in the body.

Other methods such as flame photometry, colorimetric assays, and mass spectrometry are used in certain contexts but are not as frequently employed for routine sodium measurement. Flame photometry is effective but may lack the specificity observed with ISE technology. Colorimetric assays are generally not as sensitive for low concentrations of sodium, and mass spectrometry, while highly accurate, is typically reserved for more complex analyses rather than routine sodium testing due to its complexity and cost.