Determination of Sodium and Chloride Ions in "Ditch Oil" by Tianjin Lanbo Ion Chromatography

Broadly speaking, "gutter oil" refers to non edible oil with extremely poor quality, including excessive peroxide value, acid value, moisture, carbonyl value, malondialdehyde, etc., including kitchen waste oil, oil produced from processing and refining inferior animal skins, meat, and viscera, and fried old oil. Some illegal vendors mix processed "gutter oil" with normal edible oil for sale to make huge profits, seriously endangering human health.

In the process of cooking food with edible oil, it is generally necessary to add seasonings such as salt and spices, and in the current "gutter oil" refining process, it is impossible to remove sodium chloride and other substances. In addition, according to the current refining process of "gutter oil", caustic soda (NaOH) is generally added to adjust the acid value during the refining process, thereby increasing the content of sodium ions in the "gutter oil", resulting in a sodium ion content greater than the chloride ion content. Therefore, it is very meaningful to simultaneously test the content of sodium ions and chloride ions in the "gutter oil" and determine the proportion relationship between the two through calculation.

The solubility of sodium chloride in oil is much lower than its solubility in water. Therefore, Tianjin Lanbo extracted sodium chloride from oil samples with water and used ion chromatography to determine the content of sodium ions and chloride ions in the extraction solution. The ratio of the two was analyzed, and it was proposed to be used as an indicator for the detection of "gutter oil".