Dangerous antibiotic in milk: scientists have found a way to quickly detect it

Scientists from Tomsk State University have identified a new method for detecting the antibiotic sulfaguanidine in whey using the fluorescence effect. They established the fluorescent properties of the antibiotic for its easy detection, as reported to "Gazeta.Ru" by the Ministry of Education and Science of the Russian Federation.

Sulfaguanidine is one of the most commonly used antimicrobial drugs for treating infectious diseases in animals, including cows. Often, manufacturers overuse the antibiotic, which can then appear in cow's milk. However, measuring the antibiotic content in milk is a challenging task, as the components of the product can interfere with its detection.

This antibiotic has its own intense fluorescence, so scientists decided to try measuring it using spectral and fluorescent methods.

"Traditional methods for detecting sulfaguanidine residues in food products (such as test strips or biosensors), which are commercially available and widely used, sometimes give false positive results. To develop a new measurement method, we decided to turn to spectrophotofluorimetric methods. Fluorimetric methods usually have high sensitivity, allowing for the detection and determination of very low concentrations of a substance, and optical spectroscopy is an ideal method for non-destructive sampling and real-time analysis. These methods also do not require the use of expensive reagents and equipment," Olga Chaikovskaya, professor of the Department of Optics and Spectroscopy at TSU Faculty of Physics and head of the LFFM TSU, told "Gazeta.Ru".

The analysis was conducted on whey from commercial milk of three brands - "Domik v Derevne," "Prostokvashino," and "Irbitskoe." Sulfaguanidine was added to the milk in a known concentration, after which the concentration of the substance in the whey was measured. Fluorescence and absorption analysis was carried out using spectrofluorimeter and spectrophotometer instruments, as well as bromocresol purple and methylene blue probes, which allowed for signal enhancement and increased method sensitivity.

The most effective method for measuring the antibiotic content in whey was the fluorescence method using a bromocresol purple probe. This approach provides higher sensitivity.

Future plans include the development of a portable device based on spectrophotofluorimetric methods for quick and convenient analysis of sulfaguanidine directly at the site of milk production or processing.