Total sodium in foodstuffs – new video explains the better determination method
3.4.2019

Sodium determination in foodstuffs with thermometric titration
A commonly used method for quantifying sodium in foodstuffs is to determine chloride and subsequently deduce the sodium concentration from the 1:1 stoichiometry of sodium chloride. This method involves errors because sodium is not only present with chloride as the counterion. A direct thermometric titration method for sodium solves this problem. In a new Metrohm Application Video, Lucia Meier, product specialist titration at Metrohm International Headquarters, presents this method.

Thermometric titration uses a fast responding thermometer, the Thermoprobe, as a sensor to detect the endpoint of the titration reaction. The endpoint of the titration is marked precisely by the moment when the reaction stops and no significant temperature change is registered any longer in the solution. Because the detection of the endpoint relies merely on temperature change rather than the absolute temperature, there is no need to calibrate the sensor. The Thermoprobe is furthermore essentially maintenance-free and it can be stored dry between titrations.

As for sample preparation, users only need to ensure that the sample is homogeneous. Accurate results are available in less than 2 minutes. The method is robust, can be fully automated and copes with challenging food matrices such as ketchup, instant soups, gravies, and salty snacks. Thermometric titration and its application to food samples is described in detail in a Metrohm white paper.

Follow Metrohm's YouTube channel MetrohmTV to learn about applications and instrumental solutions in chemical analysis for your lab.

> Watch the video on YouTube

> Learn more about the Titrotherm thermometric titrator

> Download the white paper

> Download pr in English