Occurrence of aflatoxins in peanuts and peanut products determined by liquid chromatography with fluorescence detection

Liquid chromatography with fluorescence detection using immunoaffinity column clean-up was a method described for determination of aflatoxins (AFB1, AFB2, AFG1 and AFG2) in peanuts and peanut based products. The validation of the procedure was performed. Good coefficient of correlation was found for all aflatoxins in the range of 0.9993-0.9999. Limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.003-0.005 mg/kg and 0.009-0.023 mg/kg, respectively, which was acceptable. The mean recovery for total aflatoxins was 88.21%. The method also showed acceptable precision values in the range of 0.171-2.626% at proposed concentration levels for all four aflatoxins. RSDR values (within laboratory reproducibility) calculated from the results showed good correlation between two analysts for all aflatoxins and they ranged from 4.93-11.87%. The developed method was applied for the determination of aflatoxins in 27 samples of peanuts and peanut based products. The results showed that 21 peanut samples (77.7%) were below LOD of the method. Three samples had positive results over the MRL. There was one extreme value recorded for the total aflatoxins in peanut (289.2 mg/kg) and two peanut based products, peanut snack and peanut, with total content of aflatoxins being 16.3 mg/kg and 8.0 mg/kg, respectively. The obtained results demonstrated that the procedure was suitable for the de­termination of aflatoxins in peanuts and peanut based products and it could be implemented for the routine analysis

Wild Boar (Sus scrofa L.) as the Biomonitor of Cadmium and Lead Pollution in the Republic of North Macedonia

Until the outbreak of African swine fever in almost the entire Europe and consequently in the Republic of North Macedonia (2022), the population of wild boars was in increase. The biological characteristics of this species make it suitable to be used as a bioindicator for environmental pollution. The concentrations of cadmium and lead (Cd and Pb) were measured using atomic absorption spectrophotometry in the liver of free ranging wild boars. Samples were taken from 608 animals, harvested in a period of 7 years (2016-2022), in 11 hunting locations that cover the whole territory of the Republic of North Macedonia. The mean value of Pb in the liver in all hunting areas was 0.225 mg·kg-1 wet weight with range of 0.154-0.722 mg·kg-1, while mean Cd was 0.366 mg·kg-1 and ranged from 0.177 to 0.464 mg·kg-1. A statistically significant difference in Cd was found between the hunting locations, while Pb differed between hunting years. The mean Cd concentrations were significantly higher in Pelagonisko, Krivorečansko and Ohridsko-Prespansko hunting areas than in those from Pološko hunting area, while the mean Pb values in 2019 and 2020 were significantly higher than the mean value determined in 2021. For Cd, 18.2% of the total number of samples exceeds the maximum allowed limit provided in the legislation, while for Pb it was 6.7%. The maximum mean value for Pb (0.336 mg·kg-1) was measured in 2020 and for Cd (0.449 mg·kg-1) in 2016. The mean values for Pb and Cd obtained in this study were in line with data reported for wild boar from other European countries

Optimization, validation and application of UV-Vis spectrophotometric-colorimetric methods for determination of trimethoprim in different medicinal products

Two simple, sensitive, selective, precise, and accurate methods for determination of trimethoprim in different sulfonamide formulations intended for use in human and veterinary medicine were optimized and validated. The methods are based on the trimethoprim reaction with bromcresol green (BCG) and 2,4-dinitro-1-fluorobenzene (DNFB). As extraction solvents we used 10 % N,N-dimethylacetamide in methanol and acetone for both methods, respectively. The colored products are quantified applying visible spectrophotometry at their corresponding absorption maxima. The methods were validated for linearity, sensitivity, accuracy, and precision. We tested the method applicability on four different medicinal products in tablet and powder forms containing sulfametrole and sulfamethoxazole in combination with trimethoprim. The results revealed that both methods are equally accurate with recoveries within the range 95-105 %. The obtained between-day precision for both methods, when applied on four different medicinal products, was within in the range 1.08-3.20 %. By applying the F-statistical test (P<0.05), it was concluded that for three medicinal products tested both methods are applicable with statistically insignificant difference in precision. The optimized and validated BCG and DNFB methods could find application in routine quality control of trimethoprim in various formulation forms, at different concentration levels, and in combination with different sulfonamides