Drug Residues In Animals Research Articles

Screening of 152 Veterinary Drug Residues in Animal Source Foods by LC-MS/MS, Multilaboratory Validation Study: Final Action 2020.04.

The presence of veterinary drug residues in food-producing animals and animal products is regulated through the enforcement of maximum residue limits (MRLs). To answer the need of the food sector to monitor these substances in a wide range of food commodities, stakeholders at AOAC INTERNATIONAL identified the need for a reliable confirmatory screening method. Such a qualitative approach is required for compliance checking and to support product release in manufacturing. Data were collected from five independent laboratories that applied the First Action Official Method 2020.04 to demonstrate adequate performance under reproducibility conditions. The probability of detection (POD) was calculated in blank test samples and test samples spiked at the screening target concentration (STC) level, with the objective to achieve PODs ≤10% and ≥90%, respectively. Additionally, the effectiveness of the screening method was evaluated by participating in 92 proficiency tests. Four streams were optimized to screen for 152 veterinary drug residues by LC-MS/MS in a wide variety of food commodities including milk-based ingredients and related products (e.g., milk fractions, infant formula, infant cereals, and baby foods), meat- and fish-based ingredients and related products (fresh, powdered, cooked, infant cereals, and baby foods), and other ingredients based on eggs, animal fat, and animal byproducts. The four streams covered 105 antibiotic residues, anti-inflammatory and antiparasitic agents (stream A), 23 beta-lactams (stream B), 14 aminoglycosides (stream C), and 10 tetracyclines (Stream D). The multilaboratory validation led to PODs at the STC ≥94% and PODs in the blank ≤9%. Further application of the multilaboratory validated method to 92 proficiency tests provided more than 99% satisfactory submitted results (n = 784). The interlaboratory reproducibility determined for this method met the acceptance criteria defined in AOAC Standard Method Performance Requirement (SMPR®) 2018.010. AOAC has approved the method for Final Action status.

Original-structure-based hapten design strategy and development of a derivatization-free gold-based paper lateral-flow immunoassays for detecting furaltadone metabolite in shrimp

Veterinary drug residues in food-producing animals pose a threat to human health and public safety, and accurate measurement of these drug residues is necessary. However, detecting nitrofuran metabolite residues is challenging because of their low molecular weight and the long derivatisation time required for their indirect detection. Current antibodies produced against these metabolites have limited accuracy and sensitivity owing to the traditional and ineffective hapten design based on the reaction of 3-amino-5-morpholinomethyl-2-oxazolidone (AMOZ) with nitrobenzaldehyde. In this study, a new antigen strategy was adopted using an original-structure-based hapten design combined with a new carrier protein with immunosynergistic effects to produce a monoclonal antibody that could recognise the metabolite of furaltadone (AMOZ) directly without derivatisation with excellent analytical performance. Finally, a gold-based paper lateral flow immunoassay for AMOZ without derivatisation was established with a visual limit of detection of 5 ng/mL, IC50 of 0.97 ng/mL and linear range (IC20∼IC80) of 0.45–2.07 ng/mL. The method was sensitive and accurate, and detection was completed within 10 min. This new antigen design strategy provides a theoretical basis and reference for antibody production of other ultrasmall molecules.

Assessing the Food Quality Using Carbon Nanomaterial Based Electrodes by Voltammetric Techniques

The world is facing a global financial loss and health effects due to food quality adulteration and contamination, which are seriously affecting human health. Synthetic colors, flavors, and preservatives are added to make food more attractive to consumers. Therefore, food safety has become one of the fundamental needs of mankind. Due to the importance of food safety, the world is in great need of developing desirable and accurate methods for determining the quality of food. In recent years, the electrochemical methods have become more popular, due to their simplicity, ease in handling, economics, and specificity in determining food safety. Common food contaminants, such as pesticides, additives, and animal drug residues, cause foods that are most vulnerable to contamination to undergo evaluation frequently. The present review article discusses the electrochemical detection of the above food contaminants using different carbon nanomaterials, such as carbon nanotubes (CNTs), graphene, ordered mesoporous carbon (OMC), carbon dots, boron doped diamond (BDD), and fullerenes. The voltammetric methods, such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV), have been proven to be potential methods for determining food contaminants. The use of carbon-based electrodes has the added advantage of electrochemically sensing the food contaminants due to their excellent sensitivity, specificity, large surface area, high porosity, antifouling, and biocompatibility.

Effects of early florfenicol exposure on glutathione signaling pathway and PPAR signaling pathway in chick liver

Florfenicol (FFC) is a common antibiotic for animals. The nonstandard and excessive use of FFC can cause veterinary drug residues in animals, pollute soil and marine environment, and even threaten human health. Therefore, it is necessary to study the toxicity and side effects of FFC on animals. Our previous studies have proved that FFC can cause liver injury in chicks, but there are few in-depth studies on the mechanism of FFC causing liver injury at the level of signaling pathway in chicks. Therefore, transcriptome and proteome sequencing were performed and combined analysis was performed. Sequencing results showed that 1989 genes and 917 proteins were significantly changed in chick livers after FFC exposure. These genes and proteins are related to redox, glutathione transferase activity and lipid metabolism. There are 9 significantly different genes and 7 significantly different proteins in glutathione signaling pathway. Oxidative stress may occur in the liver of chicks through the change of activation state of glutathione signaling pathway. And there are 13 significantly different genes and 18 significantly different proteins in PPAR signaling pathway. The changes of PPAR signaling pathway may induce lipid metabolism disorder in liver. The verification results of qPCR and PRM were consistent with the sequencing results. We also detected GSH-Px, GSH, GST, TG, TC and ANDP levels in liver. These changes of biochemical indicators directly confirmed oxidative stress and lipid metabolism disorders were occurred in the livers of chicks treated by FFC. In conclusion, FFC could induce liver injury in chicks by regulating the expression levels of significantly different genes and proteins in glutathione signaling pathway and PPAR signaling pathway.

Aquaculture management practices associated with antimicrobial residues in Southwestern Nigeria

Aquaculture production has grown rapidly in Nigeria but with unbridled use of antibiotics which predisposes fish consumers to the risks of antimicrobial residues and resistance. A cross sectional survey of antimicrobial use in aquaculture and occurrence of their residues in African Catfish (Clarias gariepinus) samples from Southwestern states of Nigeria were carried out. The results showed that majority of the farmers lacked knowledge of drug residues in aquatic animals, and the food safety and public health implications on consumers. Frequently administered antibiotics include tetracyclines (27.5%), chloramphenicol (22.0%) and gentamicin (18.4%). About 84.7% of tested fish had residues with variable prevalence which were not statistically significant. Risk factor analysis indicated that fish farmers with tertiary and secondary education were more likely to produce fish that contained antimicrobial residues than those with primary education [odds ratio (OR) = 1.91, confidence interval (CI) = 1.24–5.99 and OR = 1.25, CI = 1.08–5.27, respectively] while fish from farms managed by men were about three times more likely to contain residues (OR = 3.25, 95% CI = 1.95–9.35) than those managed by women. Hence, most of the fish from Southwestern Nigeria were indiscriminately dosed with different antibiotics that predispose consumers to the risks of antimicrobial residues with food safety and antimicrobial resistance consequences. Implementation of good fishery management practices and farmers' education are advocated to reduce dependence on antimicrobials.

Pesticide residue monitoring in marketed fresh vegetables and fruits in central Taiwan (1999-2004) and an introduction to the HACCP system

The objectives of this study are: (1) to collect and analyze the data of pesticide residues in vegetables and fruits in central Taiwan; (2) to compare the statistics of pesticide residues data in vegetables and fruits in 4 regions of Taiwan; and (3) to introduce the Hazard Analysis Critical Control Point (HACCP) system to industries and growers of vegetables and fruits for improving the safety of agricultural products. The 1999 samples of vegetables and fruits were collected from supermarkets and traditional markets by 6 local bureau of health in central Taiwan (1999-2004) and analyzed for the presence of 70∼79 pesticide residues using multiresidue analysis methods (MRMs). The detection limits of these methods ranged from 0.03 to 0.4 ppm. For central Taiwan (1999-2004), pesticide residues were either absent or compliant with the Maximum Residue Limit (MRL) in 99.8% of the samples. Only 4 samples contained a pesticide residue that exceeded the MRL (0.2%, 4 of 1999). In whole Taiwan (1997-2003), pesticide residues were detected in 13.9% of the 9955 samples and 1.2% were violative. To decrease the health risk to human and environment from exposure to pesticides, the government samples and analyzes agricultural products for pesticide residues to enforce the limits set by Department of Health every year. Risk assessment and HACCP have some overlapping components; both HACCP and risk assessment are encompassed in risk analysis. HACCP is a preventative system and will provide a high level of food safety assurance. However, effective HACCP requires the consideration of all hazards, i.e. chemical (food additives, heavy metal contamination, pesticide residues, and animal drug residues), microbiological and physical hazards. HACCP principles have been incorporated into food safety legislation in Taiwan and worldwide.

Probabilistic Physiologically Based Pharmacokinetic Model for Penicillin G in Milk From Dairy Cows Following Intramammary or Intramuscular Administrations.

Penicillin remains one of the most frequently identified violative drug residues in food-producing animals. The predominant violations of penicillin were found in cull dairy cows. In the United States, procaine penicillin G is approved to be used in dairy cows through intramuscular (IM) and intramammary (IMM) administrations. Physiologically based pharmacokinetic (PBPK) models are useful tools to predict withdrawal intervals and tissue residues of drugs in food animals to ensure food safety, especially for extralabel drug use due to the scarcity of experimental data after extralabel administrations. Currently, no PBPK model is available to predict penicillin concentrations in milk. A population PBPK model with a physiologically based compartment for the mammary gland was established for penicillin G in dairy cows. The model predicted the tissue and milk residues well based on comparison with data from previous pharmacokinetic studies. The predicted milk discard interval of procaine penicillin G administered at 10 times the label dose for 3 repeated IM administrations was 182 h, and 122 h at 4 times the label dose after 3 repeated IMM infusions. Predicted results showed that even 4 times label dose did not lead to violative tissue residues in healthy dairy cows with IMM infusions. The predominant violations found in cull dairy cows may be caused by altered pharmacokinetics due to mastitis, other diseases, and/or interactions with other drugs, which have impacts on penicillin distribution and elimination. The current PBPK model can help predict milk discard interval for penicillin following extralabel use through IM and IMM administrations.

Simultaneous analysis of aminoglycosides with many other classes of drug residues in bovine tissues by ultrahigh-performance liquid chromatography-tandem mass spectrometry using an ion-pairing reagent added to final extracts.

The way to maximize scope of analysis, sample throughput, and laboratory efficiency in the monitoring of veterinary drug residues in food animals is to determine as many analytes as possible as fast as possible in as few methods as possible. Capital and overhead expenses are also reduced by using fewer instruments in the overall monitoring scheme. Traditionally, the highly polar aminoglycoside antibiotics require different chromatographic conditions from other classes of drugs, but in this work, we demonstrate that an ion-pairing reagent (sodium 1-heptanesulfonate) added to the combined final extracts from two sample preparation methods attains good separation of 174 targeted drugs, including 9 aminoglycosides, in the same 10.5-min ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The full method was validated in bovine kidney, liver, and muscle tissues according to US regulatory protocols, and 137-146 (79-84%) of the drugs gave between 70 and 120% average recoveries with ≤ 25% RSDs in the different types of tissues spiked at 0.5, 1, and 2 times the regulatory levels of interest (10-1000ng/g depending on the drug). This method increases sample throughput and the possible number of drugs monitored in the US National Residue Program, and requires only one UHPLC-MS/MS method and instrument for analysis rather than two by the previous scheme. Graphical abstract Outline of the streamlined approach to monitor 174 veterinary drugs, including aminoglycosides, in bovine tissues by combining two extracts of the same sample with an ion-pairing reagent for analysis by UHPLC-MS/MS.

Distribution of Animal Drugs among Curd, Whey, and Milk Protein Fractions in Spiked Skim Milk and Whey.

It is important to understand the partitioning of drugs in processed milk and milk products, when drugs are present in raw milk, in order to estimate the potential consumer exposure. Radioisotopically labeled erythromycin, ivermectin, ketoprofen, oxytetracycline, penicillin G, sulfadimethoxine, and thiabendazole were used to evaluate the distribution of animal drugs among rennet curd, whey, and protein fractions from skim cow milk. Our previous work reported the distribution of these same drugs between skim and fat fractions of milk. Drug distribution between curd and whey was significantly correlated (R2 = 0.70) to the drug's lipophilicity (log P), with improved correlation using log D (R2 = 0.95). Distribution of drugs was concentration independent over the range tested (20-2000 nM). With the exception of thiabendazole and ivermectin, more drug was associated with whey protein than casein on a nmol/g protein basis (oxytetracycline experiment not performed). These results provide insights into the distribution of animal drug residues, if present in cow milk, among milk fractions, with possible extrapolation to milk products.

Detection of residues in urine and tissues of sheep treated with trace levels of dietary ractopamine HCl.

Qualitative assays are sometimes used as the sole basis for detecting drug residues in live animals or in animal products. Such assays have become increasingly sensitive as detection technologies have improved, yet the limitations of such assays to discriminate purposeful and accidental drug exposures remain poorly defined. A study was conducted to determine the ability of a ractopamine lateral flow assay to accurately detect incurred ractopamine residues in contaminated feeds and in sheep fed trace quantities of ractopamine HCl. False positive and negative samples were determined using a quantitative liquid chromatography-tandem mass spectrometric (LC-MS/MS) method. Ractopamine HCl was fed to sheep at 0 (Zero), 1 (Low), 10 (Med), or 100 (High) µg/kg of diet ( = 4 per level, 0.5 kg of feed/d) for 7 consecutive d and urine was collected daily about ∼16 h post exposure. On-site lateral flow assays were able to reliably (0% false negatives) detect 20 μg of ractopamine HCl per kg of feed. Urine from treated sheep tested positive for ractopamine residues by lateral flow assay in 7.4 (Zero), 0 (Low), 82 (Med), and 86% (High) of the urine samples from each group. Parent ractopamine was below the assay limit of quantification (LOQ, 0.7 ng/mL) in all urine samples using LC-MS/MS. After hydrolysis of ractopamine conjugates, total ractopamine (parent + hydrolyzed metabolites) in urine of Low animals was always less than the LOQ, but in 7 of 28 samples were above the limit of detection (LOD, 0.22 ng/mL). In contrast, urine in Med animals contained 1.08 to 9.13 ng/mL of total ractopamine, while urine of High animals contained 4.85-32.82 ng/mL of total ractopamine. Ractopamine is rapidly eliminated; nevertheless, > 80% of urine samples from sheep exposed to 5 µg/d (M) of ractopamine HCl had detectable residues by the screening assay and a 100% of samples had measurable ractopamine using LC-MS/MS methods. Tissue residues of ractopamine were not detected in any of the sheep. The sensitivity with which the rapid, qualitative assay detected ractopamine was sufficient to reveal trace ractopamine exposures; these data suggest that the use of qualitative tests to indicate purposeful treatment of animals (i.e., for doping or growth enhancement), in the absence of collaborating quantitative data, is inappropriate.

An update discussion on the current assessment of the safety of veterinary antimicrobial drug residues in food with regard to their impact on the human intestinal microbiome.

The human gastrointestinal tract ecosystem consists of complex and diverse microbial communities that have now been collectively termed the intestinal microbiome. Recent scientific breakthroughs and research endeavours have increased our understanding of the important role the intestinal microbiome plays in human health and disease. The use of antimicrobial new animal drugs in food-producing animals may result in the presence of low levels of drug residues in edible foodstuffs. There is concern that antimicrobial new animal drugs in or on animal-derived food products at residue-level concentrations could disrupt the colonization barrier and/or modify the antimicrobial resistance profile of human intestinal bacteria. Therapeutic doses of antimicrobial drugs have been shown to promote shifts in the intestinal microbiome, and these disruptions promote the emergence of antimicrobial-resistant bacteria. To assess the effects of antimicrobial new animal drug residues in food on human intestinal bacteria, many national regulatory agencies and international committees follow a harmonized process, VICH GL36(R), which was issued by a trilateral organization of the European Union, the USA, and Japan called the International Cooperation on Harmonization of Technical Requirements for Veterinary Medicinal Products (VICH). The guidance describes a general approach currently used by national regulatory agencies and international committees to assess the effects of antimicrobial new animal drug residues in animal-derived food on human intestinal bacteria. The purpose of this review is to provide an overview of this current approach as part of the antimicrobial new animal drug approval process in participating countries, give insights on the microbiological endpoints used in this safety evaluation, and discuss the availability of new information. Copyright © 2016 John Wiley & Sons, Ltd.

Detection of antibiotic residues in poultry carcasses in Mashhad poultry abattoir

In poultry breeding, use of any antibiotics as a food additive that promotes growth, prevention or treatment of infectious diseases will increase the chance of drug residues in poultry meat products. In this study, the presence of different antibiotics in ten broiler flocks, which were later transported to Mashhad poultry abattoir have been investigated, using four plate test (FPT) method. A total of one hundred breast muscle and sixty liver samples (10 breast muscles and 6 liver samples from each flock) were collected randomly. The results of this study showed, the 18.75% of samples were positive for antibiotic residues and 6.88% of samples were suspected. The results also showed that sulfonamides residue in meat and liver samples were higher than other investigated antibiotics (22% in meat and 11.7% in livers). It can be concluded that the withdrawal time of antibiotics before slaughter has been ignored in many of these farms therefore, the administration of antibiotics in poultry farms must be more rigidly controlled to prevent drug residues in food-producing animals.

Results of anti-mortem screening methodology to predict prescribed drug withholding periods for flunixin and ceftiofur in heifers

A simple, cow-side test for the presence of drug residues in live animals would be useful for drug residue avoidance programs. Simple inhibition tests used at slaughter do not detect some drug tolerance concentrations such as those for flunixin and ceftiofur-metabolites. This experiment evaluated an adaptation of a beta-lactam and flunixin lateral flow (LF-modification) test for use with urine and serum samples from treated heifers and determined the ability of the test to predict the labeled slaughter withhold of ceftiofur and flunixin.

Analysis of Antithyroid Drug Residues in Food Animals

In the late 1970s, concerns were raised regarding why antithyroid drugs were being administered to food animals to promote growth despite the fact that they had been implicated as being carcinogenic and teratogenic; the growth promotion process produced an inferior quality meat with increased water retention in the animal's gastrointestinal tract. An increased incidence of aplasia cutis (a characteristic scalp defect) in consumers in Spain was linked to an increased consumption of antithyroid-contaminated meat. Therefore, to protect human health, the EU banned the use of antithyroid drugs in food animal production in 1981. This article reviews the impact of this regulatory decision on the regulatory analysis of these compounds in foods of animal origin. It discusses the physiology of the thyroid gland, the chemistry of antithyroid drugs and critically evaluates the suitability of the analytical methods that have been developed and validated to support enforcement of the regulation.

Antimicrobial residues screening in pigs and goats slaughtered in Nsukka Municipal abattoir, Southeast Nigeria

Antimicrobial residue in animal food products is an important index of food safety. Drug residues could result from chemotherapeutic or chemoprophylactic use of drugs in food animals. This occurrence of residue in animal food products has received enormous worldwide attention from some local, international and public health agencies. Samples of tissues/organs from pigs and goats slaughtered at the Nsukka Municipal abattoir, Southeast, Nigeria were screened for the presence of antimicrobial residues. Samples collected from the muscles, liver and kidney of 40 slaughtered pigs and 40 slaughtered goats were analysed for antimicrobial residues using the four plate agar diffusion method. 12 (30%) of the 40 sampled pigs and 10 (25%) of the 40 sampled goats were positive for antimicrobial residues. In pigs, antimicrobial residues occur more in the kidney, muscle and liver in that order, while in goats they occurred more and equally in kidney and liver than in the muscle. The result of the study clearly suggest that the rampant use of antimicrobial drugs in slaughter animals at the Nsukka municipal abattoir coupled with non-adherence to withdrawal periods is grossly practiced in Nigeria. This study further confirms the need to regulate the use of veterinary drugs in livestock production and to enforce laws guarding against drug residues in food animals. Keywords: Residues, antimicrobial, pigs, goats

Prevalence of antimicrobial residues in raw table eggs from farms and retail outlets in Enugu State, Nigeria

The use of antimicrobial agents in poultry production results in their accumulation in the body tissues and products such as milk and egg. The subsequent accumulation of these drugs and their metabolites in body cells is known as drug residue. This study was designed to determine the prevalence of antimicrobial residues in eggs from poultry farms and retail outlets in Enugu State, Nigeria. Eggs from 25 selected commercial farms and ten retail outlets were screened for the prevalence of antimicrobial residue. Also, structured questionnaires were administered to 25 commercial farms in the state to determine the management practices and the most widely used antimicrobial drugs in farms and possible association between the management practices and the occurrence of antimicrobial residues in eggs from these farms. All the 25 farms surveyed use oxytetracycline. Eggs from nine of the surveyed farms tested positive for antimicrobial residue and three of the ten surveyed farms also tested positive for antimicrobial residue. No association was observed (p 0.05; Fisher's exact test) between the occurrence of antibiotic residues in eggs and farm size, feed source and housing systems. This study was able to demonstrate the presence of antimicrobial residues in eggs destined for human consumption. Drugs like nitrofurans which has been banned for use in food animals are still very much in use in Enugu State, Nigeria. Antibiotics given as feed additives may give rise to drug residues in food animals.

Development of veterinary drug residue controls by the Codex Alimentarius Commission: a review

Within the Codex Alimentarius, transparency is and has been an important consideration with regard to how and why actions and decisions are made in providing stakeholders with sufficient information and clarity on matters of interest and decision-making. This review focuses on the development of analytical methods performance criteria for measuring veterinary drug residues in food-producing animals for the Codex Committee on Residues of Veterinary Drugs in Foods. It describes the initial development as well as the evolution and refinement of analytical method performance criteria as well as method validation criteria from its first meeting to the present. Reference is routinely made to published Codex, Food and Agriculture of the United Nations (FAO) reports, guidance documents and manuals as well as those of other relevant analytical method standard-setting organizations with regard to analytical method performance relevant to Codex Alimentarius food safety standards development. Key Codex decisions that have substantially impacted on analytical methods-related issues are described and the subsequent outcomes. It is a reasoned conclusion that the refinement of analytical method performance criteria and validation is an ongoing process that must continuously adapt to present and future scientific issues and decisions within the Codex Alimentarius Commission and its subsidiary bodies as well as relevant analytical standard-setting organizations.

Identification and confirmation of chemical residues in food by chromatography-mass spectrometry and other techniques

A quantitative answer cannot exist in analysis without a qualitative component to give enough confidence that the result meets the analytical needs (i.e. the result relates to the analyte and not something else). Just as a quantitative method must typically undergo an empirical validation process to demonstrate that it is fit for purpose, qualitative methods should also empirically demonstrate that they are suitable to meet the analytical needs. However, thorough qualitative method validation requires analysis of a great number of samples (possibly more than can be reasonably done), which is generally avoided due to the time and the effort involved. Instead, mass spectrometry (MS) is generally assumed to be the gold standard for qualitative methods, and its results are typically unquestioned. For example, a system was developed by European regulators of veterinary drug residues in food animals (2002/657/EC), in which the number of identification points given in MS analyses depends on the general degree of selectivity of the MS technique used. This well-defined approach gives a definite answer for decision-makers, so it has grown in popularity. However, the identification-points system is not scientific. The reality is that each situation requires information gathering and careful deductive thinking on the part of the analyst to make MS identifications. Rather than devise arbitrary requirements that need to be met by an unthinking analyst, we remind the analytical community that confirmation can be given only if two or more independent analyses are in agreement, preferably using orthogonally selective (independent) chemical mechanisms. In this article, we discuss the proper use of terminology, highlight the identification power of various MS techniques, demonstrate how MS identifications can fail if precautions are not taken, and re-assert the value of basic confirmation practices, qualitative method validation, information checklists, routine quality-control procedures, and blind proficiency-test analyses.

Analytical Methods for the Detection of Corticosteroids-Residues in Animal-Derived Foodstuffs

Reliable and practicable analysis of veterinary drug residues in food-producing animals represented an important measure to ensure consumer protection. Tha main attention in this text is on the analytical methods for corticosteroids-residue detection. The progress of rapid screening methods and the use of accurate liquid chromatography-tandem mass spectrometry (LC-MS-MS) for the quantitative detection of corticosteroids were discussed. The challenges and achievements in this field, as well as an outline of future perspectives and promising alternatives for well-established procedures, were summarized. Developing highly sensitive analytical multi-residue methods to measure very low levels of corticosteroids is one aspect that should, and will, receive dedicated interest in the near future.

Veterinary drug residues in meat: Concerns and rapid methods for detection

The use of substances having hormonal or thyreostatic action as well as β-agonists is banned in the European Union. However, sometimes forbidden drugs may be added to feeds for illegal administration to farm animals for promoting increased muscle development or increased water retention and thus obtain an economical benefit. The result is a fraudulent overweight of meat but, what is worse, residues of these substances may remain in meat and may pose a real threat to the consumer either through exposure to the residues, transfer of antibiotic resistance or allergy risk. This has exerted a great concern among European consumers. The control of the absence of these forbidden substances in animal foods and feeds is regulated in the European Union by Directive96/23/EC on measures to monitor certain substances and residues in live animals and animal products. Analytical methodology, including criteria for identification and confirmation, for the monitoring of compliance was also given in Decisions 93/256/EEC and 93/257/EEC. More recently, Decision 2002/657/EC provided rules for the analytical methods to be used in testing of official samples. A crucial step is the screening of veterinary drug residues in live animals, feeds and animal products in view of the remarkable number of samples and large variety of residues to be analysed. In recent years, different rapid methods having easy performance, high sensitivity and high throughput have been proposed and are being extensively used. These methods as well as other new methods are reviewed in this manuscript.