A new method for determining iodine levels in kelp has been developed.

Researchers at the RTU MIREA have developed a methodology for determining the iodine content in laminaria, which can be utilized for quality control of medicinal plant raw materials in pharmaceutical companies. This method is not only more accurate and sensitive but also significantly less labor-intensive than traditional approaches.

2025-02-21 10:00:34https://naked-science.ru/article/column/opredeleniya-joda-v-lamin

Iodine is an essential micronutrient required for the proper functioning of the thyroid gland, which regulates metabolism in the body. A deficiency in iodine can lead to serious health issues, including impairments in brain, heart, and other organ functions. One of the best natural sources of iodine is seaweed, particularly kelp (also known as kombu). However, to utilize kelp in medicinal products or dietary supplements, it is crucial to accurately determine the iodine content in the raw material.

Researchers have developed a new method based on Inversion Voltammetry (IV). This technique employs a graphite electrode capable of "capturing" iodine from a solution and measuring its quantity with high precision. The results of the study have been published in the journal "Fine Chemical Technologies".

Leonid Martynov, an associate professor at the Department of Analytical Chemistry at the M.V. Lomonosov Institute of Fine Chemical Technologies, RTU MIREA, emphasized the significance of the new development: "The developed method will not only enhance the accuracy of analyses but also significantly simplify the quality control process of medicinal plants in laboratory conditions. The main principle of the method lies in the application of cathodic inversion voltammetry using an impregnated graphite electrode (soaked in epoxy resins), which aids in accurately measuring the iodine content in the raw material by interacting with active substances."

Unlike methods that utilize toxic substances (such as mercury), the new approach for determining iodine is environmentally safe.

Modern methods for iodine determination, such as titrimetry (iodometric titration), require complex sample preparation and may lack sufficient accuracy. Other techniques, like inductively coupled plasma mass spectrometry (ICP-MS), while very sensitive, are expensive and complicated to use, making them unsuitable for routine monitoring in production.

The method is based on an electrochemical reaction in which the iodine present in the seaweed is converted into a measurable form using a specialized electrode. For this, seaweed samples are treated with water, and then iodine is converted into the analytical form of iodides using zinc powder and sulfuric acid. The result of the voltammetric determination corresponds to the content of inorganic iodine in the tested sample.

The quality of the measurements is characterized by high accuracy and good reproducibility of results. It allows for the determination of iodine content in the range of 20 to 300 μg/L with minimal error. The method has been successfully tested on kelp samples, and its results meet the requirements of the State Pharmacopoeia of Russia.

Implementing the method does not require the use of complex equipment. The method allows for the determination of even small amounts of iodine with high precision. The process of sample preparation and measurement takes significantly less time compared to traditional methods.

The developed method can be utilized not only in scientific research but also in the industry for quality control of raw materials in pharmaceutical enterprises. This is particularly important for the production of medicinal products and dietary supplements based on seaweed, where the precise iodine content is critical. The research was supported by the Russian Science Foundation.