Determination of Diazinon Residue in Honey Samples from Mane and Samalqan Region in North Khorasan Province Using UV-Vis Spectrophotometry

IntroductionIn 2023, North Khorasan province hosted 188,000 bee colonies, producing over 2,900 tons of honey. Approximately 20% of the honey in the province is produced in the Mane and Semelqan region, which is rich in orchards and agricultural fields. To increase agricultural production, various pesticides are widely used in this area, thereby increasing the potential for contamination of bees and their products, which are often located near these fields. Pesticides residues have been reported to be toxic, carcinogenic, and capable of causing chromosomal changes (Demirhan et al., 2019). They can also affect the endocrine, reproductive, and nervous systems (Brander, Gabler, Fowler, Connon, & Schlenk, 2016; Watermann et al., 2016; Febvey, Schüz, & Bailey, 2016). Diazinon, an organophosphorus insecticide, is classified in the second category of the World Health Organization's classification and is considered a relatively dangerous pesticide (Taghavi, Naghipour, Mohagheghyan, & Jamali, 2007). This study aims to investigate the residual levels of diazinon in honey produced in the Mane and Semelqan region, including Buor Buor village (cotton flower honey), Chakhmaghloo village (kanar honey), Keshanak village (spring honey), and Darkesh village (thyme honey), with the goal of evaluating the safety of honey produced in this region.Materials and MethodsHoney samples were collected in the spring (May) and winter (March) of 2023. To prepare the honey samples for determining diazinon pesticide residue, the method of Jime´nez, Bernal, & Lorente, (2000) was used. A standard dilution of diazinon was prepared at concentrations of 0.12, 0.06, 0.024, 0.012, and 0.006 ppm. The absorption spectrum of the diluted solutions was then recorded using an ultraviolet-visible (UV-Vis) spectrometer in the wavelength range of 200 to 400 nm. Based on the spectral results, the maximum absorption wavelength (λ_max) of diazinon was determined to be 292 nm. The best-fit equation with a correlation coefficient (R² = 0.9905) was calculated. Data were analyzed using a completely randomized design with five replicates for each season (spring and winter) through the GLM procedure of SAS 9.1 statistical software (SAS, 2009).Result and DiscussionThe results showed that the amounts of diazinon in the honey samples from Buor Buor, Darkesh, Keshanak, and Chakhmaghloo villages were 3.46, 2.73, 1.81, and 1.49 ppm, respectively. The diazinon residue in the honey from Buor Buor (3.46 ppm) and Darkesh (2.37 ppm) villages was significantly higher than the diazinon residue in the honey from Chakhmaghloo (1.49 ppm) and Keshanak (1.81 ppm) villages (P < 0.001). Additionally, the residual amount of diazinon in honey harvested in the spring was 4.23 ppm, significantly higher than in the winter samples, which had 0.34 ppm (P< 0.001). Unfortunately, the residual amount of diazinon pesticide in all honey samples from different regions of Mane and Semelqan exceeded the standard limit set by authorities in Iran and Europe. ConclusionIt can be concluded that the honey from Mane and Semelghan region contains higher levels of diazinon residue compared to the standard limit, which can be attributed to the spraying of pesticides in orchrds and fields. Additionally, the lower pesticide residue in the winter honey samples may be due to manual feeding of bees, reduced agricultural activity during the winter season, and possibly the washing off of pesticide residues by rainfall. Therefore, considering the higher levels of diazinon residue in the honey samples compared to the permissible limit, and the higher amount in this residue during the spring season, it is recommended to strengthen the monitoring of pesticide application in agricultural fields surrounding beekeeping areas, particularly in the spring. Additionally, educating farmers on the proper use of pesticides, informing beekeepers about high-risk areas, and regularly screening honey samples can help reduce the risks associated with pesticide residues. Investigating safer alternatives to diazinon and establishing regional regulations are also among recommended measures to improve food safety and protect consumer health.