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A reliable, simple and sensitive liquid chromatography-electrospray ionisation-tandem mass spectrometry (LC-ESI-MS/MS) confirmation method has been developed for chloramphenicol (CAP) determination in honey, fish and prawns. For honey, samples were extracted with ethyl acetate, an aliquot was evaporated to dryness and re-dissolved in mobile phase. For fish and prawns, tissues were extracted with acetonitrile and chloroform. The organic layer was evaporated to dryness and the residue was re-constituted with water: acetonitrile (90:10). LC separation was achieved on a C18 column with gradient elution using a mobile phase of acetonitrile and water. Analysis was carried out on a triple-quadrupole tandem mass spectrometer in multiple reaction monitoring (MRM) mode via electrospray interface operated in negative ionisation mode, with deuterated chloramphenicol-d(5) (d(5)-CAP) as internal standard. Method validation was performed according to the criteria of Commission Decision 2002/657/EC. Four identification points were obtained for CAP with one precursor ion and two product ions. The limit of detection (LOD) was 0.02 µg kg(-1). Linear calibration curves were obtained over concentration ranges of 0.1-1.0 µg kg(-1) in tissues. Mean recoveries ranged from 85.5% to 115.6%, with the corresponding intra- and inter-day variation ranging from 1.0% to 22.5%, depending on matrix type and level of concentration. The decision limit (CCα) and detection capability (CCβ) of the method were obtained for all matrices: 0.04 and 0.06 µg kg(-1), respectively, for prawns and fish and 0.05 and 0.09 µg kg(-1) for honey.

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Detecção de resíduos de enrofloxacina por ensaio imunoenzimático e cromatografia líquida acoplada à espectrometria de massas em ovos comerciais de galinha após tratamento RESUMOA enrofloxacina é um dos antimicrobianos mais utilizados na avicultura industrial, e a deposição de resíduos em produtos avícolas, como os ovos, são de grande importância para a saúde pública. Na legislação brasileira não existe padronização do período de carência para o seu uso na produção avícola e não há Limite Máximo de Resíduo (LMR) fixado para enrofloxacina em ovos. Neste estudo, foi utilizado o kit de ELISA comercial (Bioo Scientific®) e a LC-MS/MS na pesquisa de enrofloxacina em ovos de 30 galinhas tratadas previamente via água de bebida, com 10mg/kg de enrofloxacina, durante cinco dias. Seis ovos foram coletados diariamente e analisados durante o tratamento e após a sua suspensão, durante 15 dias. A deposição de resíduos obteve níveis máximos no quinto dia de tratamento das aves, declinando gradativamente até não ser detectada a partir do nono dia de suspensão do tratamento. Considerando como base o LMR de 100µg/kg fixado pelo Brasil para tecidos comestíveis de aves e pela União Europeia para músculo, gordura e pele, após seis dias de suspensão do tratamento, os níveis de resíduos foram inferiores a esse limite, tendo como médias 37,43µg/kg na LC-MS/MS e 14,731µg/kg no ELISA. Dentro das condições deste estudo, um período de carência de seis dias seria mais adequado para utilização dos ovos para consumo humano. Foram detectados valores de resíduos nos ovos menores no ELISA em relação à LC-MS/MS para a mesma amostra, mas os dois métodos apresentaram concordância estatística entre si. A LC-MS/MS é o teste recomendado pela legislação brasileira para a análise de resíduos em alimentos; entretanto, pelos resultados obtidos, o kit de ELISA utilizado também pode ser aplicado na detecção de resíduos de enrofloxacina em ovos, com as vantagens de rapidez e simplicidade. Palavras-chave: enrofloxacina, resíduos, ovos, LC-MS/MS, ELISA ABSTRACT Enrofloxacin is one of the most used antibiotics in the poultry industry and the deposition of residues in poultry products

The traffic of international animal products can be public health hazard when legal import sanitary procedures are not followed. In Brazil, due to its extensive border area, the importation of animal products is a common practice in many areas of the country, especially in Rio Grande do Sul (RS), a state that borders Argentina and Uruguay. The objective of this study was to evaluate the presence of veterinary drug residues (antibiotics and antiparasitics) in animal products consumed in the state of Rio Grande do Sul, Brazil. In this study, the presence of residues of veterinary drugs (antibiotics and antiparasitics) was assessed in 189 meat (beef, pork and chicken) processed dairy and meat product samples, bought in Argentina (n=90) and Uruguay (n=99). Residues of veterinary drugs were detected in 50 (26.45%) samples, 28 presenting antibiotic (14.81%) and 22 antiparasitic (11.64%) residues. From the 50 positive samples, 40% (15 from Argentina and 5 from Uruguay) had a maximum residues above the MRLs. From these, 12 presented residues above the MRLs for antiparasitics (11 beef samples with ivermectin and one pork sample with ivermectin and doramectin) and 8 for antibiotics (two pork and two sausage samples with doxycycline; two cheese samples with doxycycline and chlortetracycline; one poultry meat sample with chloramphenicol; and one cheese sample with monensin). Due to their potential toxic effects on humans and antibiotic resistance, the presence of these residues above the legal parameters indicates a potential risk to public health. The possible negative impact on public health of the consumption of imported animal products can be reduced with an effective surveillance system and educational campaigns for the general population.

Antibacterial are widely used in veterinary applications for diseases treatment and prophilatic purposes. Inadequate uses of these drugs can lead of undesirable residues in honey for consumption. In Brazil, the legal authorities set a maximum residue limit (MRL) for different compound in honey, ranging from 10 to 20 ng ml-1. The monitoring of antibacterials is a concern, since it constitutes a risk to human health and collaborates with the growth of resistant bacteria. Brazil has the National Residue Control Plan (NRCP) to ensure that the products traded are compliant with the safety and quality criteria required by consumers. The goal of this work was to develop and validate a method suitable to determine sulfonamides, tetracyclines and macrolides in honey, using liquid chromatography tandem mass spectrometry. The main objective was to develop an efficient technique, combining simplicity, speed and low cost, since the method will be employed in routine analysis. Recoveries between 36 to 139% were obtained. Good linearity (r2) above 0.95, considering three different days, for all drugs was achieved in concentrations ranging from 0 to 200% of the MRL. Intraday and inter-day precision with CV% (n=6) lower than 18%, in agreement with specifications were obtained in concentrations ranging from 0.5 to 1.5 MRL, except for erythromycin. Accuracy was between 97 to 108%. Limits of quantitation for macrolides were 2.5 ng g-1and for sulfonamides and tetracyclines were 5 ng g-1. Decision limit (CCα) was evaluated and the results obtained were between 12.9 to 28.1 ng g-1. The detection capability (CCβ) obtained was between 15.8 to 36.3 ng g-1. The proposed method demonstrated to be suitable for this intended purpose and will contribute to antibacterial honey monitoring.