Chapter 10 Veterinary Drug Residues

Development of an Analytical Method for Detection of Anesthetics and Sedatives in Fish

BACKGROUND

Anesthetics and sedatives are frequently used to prevent abrasions caused by stress and facilitate fish management. However, drug residues may persist and cause changes in fish conditions and induce side effects. In addition, drugs that are not permitted for use in edible fish are sometimes potentially used in fish. The drugs can also be found in wastewater and are likely to be detected in fish.

OBJECTIVE

The purpose of this study was to establish a quantitative analytical method for 10 anesthetic and sedative (azaperone, chlorpromazine, diazepam, estazolam, haloperidol, nitrazepam, nordiazepam, oxazepam, perphenazine, and temazepam) residues in fish sold in Korean markets.

METHODS

Shrimp, flounder, and eel samples were selected as matrices. Acetonitrile (ACN) containing 0.1% formic acid was selected as an extraction solvent for shrimp and 100% ACN for flounder and eel. The QuEChERS method with C18 and PSA was used as the extraction procedure, and the analysis was performed by LC-MS/MS.

RESULTS

Limit of quantitation, recovery, accuracy, and precision were validated, and satisfactory results were obtained for the drugs. All results applied to the real samples were negative.

CONCLUSION

An optimal validation method was studied. Since the results for all samples were negative, it is considered that additional studies are needed by increasing the number of drugs.

HIGHLIGHTS

The most effective QuEChERS pretreatment method and conditions of LC-MS/MS for the analysis of anesthetics and sedatives in fish were established.

Assessment of Antimicrobial and Pesticide Residues in Food Products Sourced from Peasant Family Farming in Chile

The presence of antimicrobial and pesticide residues in products sourced from peasant family farms selected from eight regions of Chile was determined. A total of 204 samples were analyzed from family farm products, including honey, lettuce, tomato, strawberry, raspberry, lamb meat, and cow's milk. Pesticide residues were found in 43 of 107 samples tested for them, but only 4 samples had concentrations that exceeded the maximum residue limits (MRLs) set by Chilean regulations. As for animal products, 2 of 15 cow's milk samples tested positive for permethrin residues; however, these concentrations did not exceed Chilean MRLs. No pesticide residues were detected in honey samples. As for antimicrobial drugs, 4 of 14 lamb meat samples and 11 of 79 cow's milk samples tested positive for different classes of antimicrobial residues, such as tetracyclines, macrolides, aminoglycosides, and β-lactams. Among these, only three samples exceeded the MRLs for these matrices. Traces of tetracyclines and sulfonamides were detected in 7 of 29 honey samples. These findings show that these chemical contaminants are present in trace concentrations in foodstuffs produced by peasant family farms in Chile; however, most residues did not exceed the regulatory limits. This study is the first assessment of the presence of residues from antimicrobial drugs and pesticides in food products sourced from peasant family farms in Chile. Data about the current state of drug residues in this segment of food products provide a baseline for efforts to close possible gaps in current surveillance schemes.

Label-free colorimetric detection of tetracycline using analyte-responsive inverse-opal hydrogels based on molecular imprinting technology

Analyte-responsive inverse-opal hydrogels based on molecular imprinting technology were fabricated for selective, sensitive, and label-free colorimetric detection of tetracycline.