Integrated Radiometric and Complementary Techniques for Mixed Contaminants and Residues in Foods

Colombia: Four analytical methods were developed and validated. These are suitable for the determination of different classes of chemical hazards such as pesticides, veterinary drugs, mycotoxins, polychlorinated biphenyls, polyaromatic hydrocarbons in different food matrices. The scope of analysis increased from 200 compounds to 460 compounds from different groups which will result in better service-delivery to end users and increasing confidence in the institution’s analytical capabilities. Atrazine-d5, Fenthion D6, 13C g-HCH, Sufapiridina- (Phenyl-13C6), Sulfaquinoxaline (Phenyl-13C6) and flubendazole-d3 were used. Two PhD and six MScs benefited from the CRP. The CSI has initiated work on potential application of artificial intelligence in processing large analytical data.
North Macedonia: Four analytical methods were established enabling the CSI increase food safety testing capabilities. An isotopic confirmatory method for 49 veterinary drugs, organophosphate pesticides and mycotoxins was used to analyze imported and local samples of bovine meat. Another isotopic confirmatory method was established for 69 multiclass antimicrobials, anabolic hormones, lactones, ß-agonists, mycotoxins and organochlorine pesticides in bovine milk. Commercial milk samples were analysed with this method. A third isotopic confirmatory method was established for 72 multiclass antimicrobials, thyreostats, anabolic hormones, lactones, ß-agonists, mycotoxins and organochlorine pesticides in bovine urine. This work has benefited national residue testing for local needs, cutting back on outsourcing of tests; and in serving two neighboring countries, generating revenue. A stable-isotope-supported analytical method was established for residues of five antimicrobials in milk and waste after single dose administration to cows. A correlation was established between the presence of these antimicrobial residues in food and animal waste samples, and of antimicrobial resistance in intestinal microbiota, especially E. coli. More knowledge was gained on AMR testing such as the profiling of E. Coli resistance patterns in dairy cows. The project benefited 1 PhD and 1 MSc students.
Pakistan: Innovative cost-effective radioreceptor assay (RRA) technique using 14C- and 3H-labelled radiotracers for analysis of drug residues and mycotoxins was developed using inhouse receptors. RRA depends on commercial kits, whose procurement, shipping and delivery to end users is a challenge. Member States can produce receptors in-house cutting down the cost of kits. The receptors were packaged into commercial-like tablets and there are plans to scale up and share with other countries. Two MPhil students benefited from the CRP.
Ecuador : The CSI institute is responsible for regulating animal (including products) and plant health but it never had analytical methods to confirm chemical hazards in food before the CRP, let alone methods that can be used for mixed hazards but this has now changed. A method was established for testing residues of both veterinary drugs and pesticides in beef, pork and poultry meat under the country’s national monitoring programmes. Stable isotopes including atrazine-d5; enrofloxacin-d5; sulfamerazine-d4, clenbuterol-d9 and chloramphenical-d5 were used.
Peru: Two isotopic confirmatory analytical methods were developed and validated for testing multiple pesticide residues and mycotoxins in paprika and quinoa to support routine food safety control for agroexport or local consumption. Tebuconazole-d6 and dimethoate-d6; 13C-aflatoxin B1, 13C-deoxynivalenol, 13C-Fumonisin B1 and 13C-zearalenone were used. Peru’s agroexportation generates national revenue and creates jobs. In 2022 the exports accounted for 9807 US million dollar, with 102 and 94 US million attributed to paprika and quinoa, respectively. However, this is often affected by rejections at export destinations due to chemical contamination. In 2022, 37 notifications related to mycotoxins and/or pesticides in paprika were issued by EU. Similar concerns were reported about pesticides in quinoa. The CRP findings can help in redressing these challenges. One PhD student benefited from the CRP.
Chile: The stable-isotope dilution and related methodologies were developed and used for the determination of mycotoxins as well as antimicrobial and pesticide residues in broiler chicken droppings and litter. This is a non-invasive sampling method for collecting information on antimicrobial resistance. Residues and genes associated with antimicrobials tetracyclines and fluoroquinolones were detected suggesting release of both into the environment. Isotopic standards (6) used included: tetracycline-d6, enrofloxacin-d5 HCl, 13C6sulfamethazine-phenyl hemihydrate, chloramphenicol-d5, erythromycin-N-methyl-13C, d3 and hexaflumuron-d3. The CSI used the methods to analyze samples from the poultry industry. Samples from untreated birds contained enrofloxacin. The CSI provided guidance on avoiding or treating litter such from such birds. The institution is now part of the World Organization of Animal Health's collaborating centre for antimicrobial stewardship in aquaculture.
Botswana: Two methods validated will be used to enhance the implementation of the national residue monitoring programme and reduce analytical/subcontracting costs and turnaround time. Two PhD and 1 MSc students benefited from the project while the CSI also assisted two other PhD students from local universities. Stable isotope labelled compounds (16) used included tetracycline-d6, sufamethazine-d4, sulfapyridine-d4, lincomycin-d3, spiramycin-d3, enrofloxacin-d5, difloxacin-d5, xylazine-d6, mebendazole-d3, albendazole-d3, triclabendazole-d3, ceftiofur-d3, flunixin-d3, carbaryl-d7, 13C20-ochratoxin A, and 13C18-zearalenone.
China: Stable-isotope (e.g. enrofloxacin-d5, amantadine-d15, chloramphenicol-d5, florfenicol amine-d3, dexamethasone-d4 and 13C6-sulfaphenazole)-analytical methods were developed, validated and used for simultaneous determination of over 244 chemical contaminants/residues including veterinary drugs, mycotoxins and pesticides in eggs, chicken and milk. There are plans to transfer methods to other provinces for application. A database for 245 drugs and 323 pesticides established will facilitate synthesis of laboratory findings. One PhD and two MSc students were trained.
Papua New Guinea: The project enhanced capabilities of the National Agricultural Research Institute to analyze mixtures of chemical hazards in food. A multiresidue isotope-dilution LC-MS/MS method for simultaneous analysis of aflatoxin M1, ochratoxin A, deltamethrin, permethrin, cypermethrin, amitraz, amoxicillin, doramectin, eprinomectin and abamectin in milk was developed. Radioreceptor assay screening of residues/contaminants in milk was enhanced. Offshoot work included analysis of cadmium, lead, copper and zinc in rice by ICP-MS.
Uganda: Two isotope-based mass spectrometric methods were developed and validated for over 100 pesticide residues and mycotoxins in cereals (maize/maize products, rice, wheat/wheat products); and pesticide and mycotoxins in fruits and vegetables. The techniques will support routine testing by Uganda National Bureau of Standards. Twelve stable isotope-labelled compounds: 13C17-AFB1, 13C34-FB1, 13C15-deoxynivalenol, 13C20-OTA, atrazin-d5, dichlorvos-d6, diuron-d6, chlorpyrifos-d10, imidacloprid-d4, 13C6-carbaryl, deltamethrin (phenoxy)-d5, tebuconazole-d9, were used.
Benin: Isotopic-dilution LC-MS/MS method was developed for testing 17 chemicals including acrylamide, poly aromatic hydrocarbons and aflatoxins in roasted coffee, dry/smoked fish and infant formula. The method was successfully used in proficiency testing and will in future be useful for total diet studies to facilitate exposure assessment and risk management of chemical hazards.