Analysis of veterinary drug residues in fish and shrimp composites collected during the Canadian Total Diet Study, 1993–2004

Analysis of chemical contaminants in fish using high resolution mass spectrometry - A review

High resolution mass spectrometry (HRMS) has become an important tool in environmental and food safety analysis. This review highlights how HRMS has been used to analyze chemical contaminants in fish. Measuring and documenting chemical contaminants in fish serves not only as an indicator of environmental conditions but can also monitor the health of these animals and help protect an important source of human food. The incidence and significance of contaminants including veterinary drugs, human drugs and personal care products, pesticides, persistent organic pollutants, per- and poly fluorinated substances, and marine toxins will be reviewed. The advantage of HRMS over traditional MS is its ability to expand the number of compounds that can be detected and identified. This is true whether HRMS is used for targeted analytes, or more broadly for suspect screening and nontargeted analyses. The classes of compounds, types of fish or seafood, options for data acquisition and analysis, and reports of unexpected findings from recent HMRS methods for chemical contaminants in fish are summarized.

Malachite green and leucomalachite green in fish: a global systematic review and meta-analysis

Malachite green (MG), an antibiotic with antifungal activity, is illegally used in aquaculture. Given that this chemical is teratogenic and mutagenic, abstinence from intake seems to be a need for public safety. The goal of this systematic review and meta-analysis was to determine the global contamination of fishes by MG and its reduced metabolite, leucomalachite green (LMG), in a number of marine and farmed fish species. For literature published prior to January 2022, several databases (Web of Science, PubMed, and Scopus) were investigated. In total, 20 publications (10 countries, 724 samples) achieved the criteria for inclusion. The overall average MG and LMG concentrations were 0.48 (95% CI: 0.47, 0.49 µg kg^-1) and 0.59 (95% CI: 0.39, 0.79 µg/kg^-1), respectively. Eel (M. albus) 15.50 (95% CI: (14.39, 45.39 µg kg^-1) and eel (A. anguilla) 4.46 (95% CI: 1.23, 7.69 µg kg^-1) had the greatest contamination of MG and LMG, according to the effect size, respectively. Warm-water fish had a concentration of 2.591 (95% CI: 2.25, 2.93 µg kg^-1) while cold-water fish had a concentration of 1.55 (95% CI: 0.25, 2.84 µg kg^-1). Fish containing medium-fat level of 1.86 (95% CI: 1.27, 2.44 µg kg^-1) and high-fat content of 1.10 (95% CI: 0.93, 1.26 µg kg^-1) had accumulate MG and LMG in their tissues, respectively. As a result, total MG observed in countries including China, Iran, and the Netherlands was higher than authorized (2 µg kg^-1). The toxicity of MG and LMG demands more monitoring, especially in countries where these chemicals' residues are significant.

Determination of 15 human pharmaceutical residues in fish and shrimp tissues by high-performance liquid chromatography-tandem mass spectrometry

An efficient, reliable, and sensitive multiclass analytical method has been expanded to simultaneously determine 15 human pharmaceutical residues in fish and shrimp tissue samples by ultra-high-performance liquid chromatography-tandem mass spectrometry. The investigated compounds comprise ten classes, namely, analgesic, antibacterial, anticonvulsant, cardiovascular, fluoroquinolones, macrolides, nonsteroidal anti-inflammatory, penicillins, stimulant, and sulfonamide. A simple liquid extraction procedure based on 0.1% formic acid in methanol was developed. Chromatographic conditions were optimized, and mobile phase A was 0.1% ammonium acetate, and mobile phase B was acetonitrile. The mobile phase's gradient program was as follows: 0-2 min, 15% B; 2-5 min, linear to 95% B; 5-10 min, 95% B; and 10-12 min. The limits of detection were from 0.017 to 1.371 μg/kg, while a quantification range was measured from 0.051 to 4.113 μg/kg. Finally, amoxicillin, azithromycin, caffeine, carbamazepine, ciprofloxacin, clarithromycin, diclofenac, erythromycin, furosemide, ibuprofen, ketoprofen, naproxen, sulfamethoxazole, tetracycline, and triclosan were quantifiable in fish and shrimp samples.

Mechanochemical Preparation of Protein : hydantoin Hybrids and Their Release Properties

Mechanochemistry is a versatile methodology that can be employed both for covalent bond formation in organic synthesis as well as a mediator to allow preparation novel colloidal dispersions for drug delivery. Herein, ball-milling was employed for the solid-state preparation of fluorescent hydrophobic hydantoins, followed by the unprecedented mechanochemically-mediated complexation of hydrophobic hydantoins within hydrophilic protein β-lactoglobulin (BLG) and BLG nanofibrils (BLGNFs). These hydantoin:protein materials were in turn incorporated into hydrogels. The effect of incorporation of hydantoins into proteins, as well as the effect of protein structure, on the release properties were then investigated. The conversion of BLG to BLGNFs led to a more sustained release demonstrating that heat treatment of BLG into BLGNFs could be employed to modify release properties. To the best of our knowledge, this is the first example where protein : hydantoin complexes were prepared by mechanochemical methodology and mechanochemistry was combined with self-assembly in order to prepare protein nanomaterials for drug-delivery applications. In addition, the use of the developed protein materials is not limited to delivery of drugs but can for example be employed as components of smart food (delivery of nutrients) or release systems of pesticides.

Application of non-target analysis to study the thermal transformation of malachite and leucomalachite green in brook trout and shrimp

The fate of malachite green and its main metabolite leucomalachite green during thermal treatment was examined in seafood (brook trout and white shrimp) using non-target analysis. Samples were extracted using QuEChERS and analyzed using liquid chromatography coupled with quadruple time of flight mass spectrometry. Malachite green levels were reduced in meat during boiling (∼40%), microwaving (64%), and canning (96%). Only microwaving was successful in significantly decreasing leucomalachite green levels in brook trout. The reduction percentages of the two target analytes were not significantly different in shrimp (mean fat content = 0.8 ± 0.3%) and in brook trout (mean fat content = 3.5 ± 1.7%), suggesting that a higher fat content may not affect the reduction of the more lipophilic leucomalachite green in these two matrices. Three transformation products were tentatively identified in the cooked tissues, resulting from the cleavage of the conjugated structure or through demethylation. Further research is needed to determine possible adverse health effects. The findings of this study show how non-target analysis can complement targeted methodologies in identifying and evaluating risks to human health.

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Non-target analysis was applied to study the fate of malachite/leucomalachite green.

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Thermal processing significantly reduced malachite green in seafood by up to 96%.

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Leucomalachite green levels were significantly reduced only after microwaving.

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Three transformation products were tentatively identified.

A preliminary survey of antibiotic residues in frozen shrimp from retail stores in the United States

Shrimp are an important and valuable commodity for aquaculture that are widely traded internationally. Widespread antibiotic use has been documented in shrimp farming and is a common source of criticism of aquaculture products. Additionally, previous reports have found some evidence of antibiotic residues in shrimp samples obtained from retail stores in the United States, which is a concern for consumers. To further understand the prevalence of antibiotics in retail shrimp in the United States, shrimp samples obtained from grocery stores across 16 states were analyzed for 74 antibiotic compounds/metabolites at a commercial laboratory. 68 samples were analyzed for a multiclass antibiotic panel which included 66 antibiotics while a subset of 15 samples were analyzed for β-lactam antibiotics, Nitrofurans, and Oxytetracycline. Samples were obtained that were labeled as being from major production countries, including India, Indonesia, Thailand, and Vietnam. No detectable antibiotic residues were found in this survey in any samples. This is contrary to previous findings in frozen shrimp analyzed for antibiotics, which typically report low levels of the prevalence of antibiotics.

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Shrimp were collected from grocery stores in various locations in the US.

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68 samples were tested for a panel of 66 antibiotics.

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15 samples were tested for β-lactam, nitrofuran, and tetracycline residues.

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Testing showed no positive results for antibiotic residues.

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Larger surveys are needed to determine the presence of antibiotics in shrimp products.

Chloramphenicol and sulfonamide residues in sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) fish from aquaculture farm

There are many worries about the food safety of seafood contaminated with antibiotic residues. These residues can be potentially dangerous for public health owing to the causation of allergic reactions, toxic effects, and serious health problems. This study was planned to search the occurrence of chloramphenicol (CAP) and sulfonamide residue in sea bream and sea bass. A total of 82 fish samples were collected from 14 different sales points in Afyonkarahisar. The samples were analyzed for CAP and sulfonamide residues using the ELISA method. Results showed that up to 18.3% of the samples were contaminated with CAP. In the positive fish meat samples, the CAP residue concentrations ranged within 0.54-10.6 ng kg^-1. The mean CAP residue concentration in positive samples was 4.25 ± 2.78 ng kg^-1. No sulfonamide residue was detected from the samples. Despite the prohibition of CAP application in aquaculture, detectable CAP residues in fish meat samples indicate an illegal use of this antibiotic. Therefore, the results obtained in the study are negative signs for food safety. Official controls must be performed rigorously in accordance with the national residue monitoring plan especially for the illegal antibiotics.

Quinolone and Organophosphorus Insecticide Residues in Bivalves and Their Associated Risks in Taiwan

Bivalves, such as freshwater clams (Corbicula fluminea) and hard clams (Meretrix lusoria), are the most extensive and widely grown shellfish in land-based ponds in Taiwan. However, few studies have examined the contamination of bivalves by quinolone and organophosphorus insecticides. Thus, we adapted an established procedure to analyze 8 quinolones and 12 organophosphorus insecticides using liquid and gas chromatography–tandem mass spectrometry. Surveys in Taiwan have not noted high residual levels of these chemicals in bivalve tissues. A total of 58 samples of freshwater or hard clams were obtained from Taiwanese aquafarms. We identified 0.03 mg/kg of enrofloxacin in one freshwater clam, 0.024 mg/kg of flumequine in one freshwater clam, 0.02 mg/kg of flumequine in one hard clam, 0.05 mg/kg of chlorpyrifos in one freshwater clam, 0.03 mg/kg of chlorpyrifos in one hard clam, and 0.02 mg/kg of trichlorfon in one hard clam. The results indicated that 5.17% of the samples had quinolone insecticide residues and 5.17% had organophosphorus residues. However, the estimated daily intake (EDI)/acceptable daily intake quotient (ADI) indicated no significant risk and no immediate health risk from the consumption of bivalves. These results provide a reference for the food-safety screening of veterinary drugs and pesticides in aquatic animals. Aquatic products should be frequently screened for residues of prohibited chemicals to safeguard human health.

Antimicrobial Residues in Chicken and Fish, Chittagong, Bangladesh

A cross-sectional observation and an intervention study were conducted in Chittagong, Bangladesh in 2015 to assess the status of antimicrobial residues in chicken and fish. The samples were tested for selected antimicrobials (amoxicillin, ciprofloxacin, oxytetracycline and enrofloxacin) using thin-layer chromatography (TLC). The TLC-based overall prevalence of residues was 87.9% in chicken (N = 182) and 56.9% in fish (N = 153). The prevalences in chicken in June (N = 91) and in October (N = 91), respectively, were 91.2% and 83.5% (amoxicillin), 1.1% and 1.1% (enrofloxacin), 1.1% and 0% (ciprofloxacin), and 0% and 6.6% (oxytetracycline). In fish, the prevalence in September (N = 74) and in October (N = 79) was 52.7% and 44.3% (amoxicillin) and 1.4% and 27.8% (oxytetracycline), respectively. The mean concentration of amoxicillin residue was evaluated by ultra-high-performance liquid chromatography to be 508.4 mg/kg (chicken) and 515.4 mg/kg (fish). The random effect model identified market (Chawkbazar vs. Boalkhali: OR 5.7; Steelmill bazar vs. Boalkhali: OR 5.6) as significant factors for amoxicillin residue in chicken. Amoxicillin concentration was significantly reduced in chicken of Kazirhat (β= - 1.3) and Chawkbazar (β= - 1.1) and increased in October (β= 0.77) based on a generalized linear model (GLM). Climbing perch fish had significantly more risk of having amoxicillin residue than that of Bombay duck (OR = 0.05). All samples were treated by washing, boiling and cooking with spices, and then, TLC-based screening of amoxicillin residues was done. A subset of each treated group was evaluated by UHPLC. Treatment reduced amoxicillin residue levels significantly.

Health Risk Assessment of Banned Veterinary Drugs and Quinolone Residues in Shrimp through Liquid Chromatography–Tandem Mass Spectrometry

The presence of antibiotic residues in seafood and their effect on public health constitute a matter of concern for consumers worldwide. Antibiotic residues can have adverse effects on both humans and animals, especially residues of banned veterinary drugs. In this study, we applied a validated method to analyze veterinary drug residues in shrimp, including the levels of banned chloramphenicol, malachite green, leucomalachite green, and four nitrofuran metabolites as well as thiamphenicol, florfenicol, and five quinolones, which have no recommended maximum residual levels in shrimp tissues in Taiwan. We collected 53 samples of whiteleg, grass, or giant river shrimp from Taiwanese aquafarms and production areas from July 2016 to December 2017. We found 0.31 ng/g of a chloramphenicol in one grass shrimp, 5.62 ng/g of enrofloxacin in one whiteleg shrimp, 1.52 ng/g of flumequine in one whiteleg shrimp, and 1.01 ng/g of flumequine in one giant river shrimp, indicating that 7.55% of the samples contained veterinary drug residues. We evaluated the health risk by deriving the estimated daily intake (EDI). The quinolone residue EDI was below 1.0% of the acceptable daily intake recommended by the United Nations Food and Agriculture Organization and World Health Organization. The risk was thus discovered to be negligible, indicating no immediate health risk associated with shrimp consumption. The present findings can serve as a reference regarding food safety and in monitoring of the veterinary drug residues present in aquatic organisms. Continual monitoring of residues in shrimp is critical for further assessment of possible effects on human health.

Generation and immunity effect evaluation of biotechnology-derived Aeromonas veronii ghost by PhiX174 gene E-mediated inactivation in koi (Cyprinus carprio koi)

Aeromonas veronii is a conditional pathogen causing high mortality in many freshwater fish species worldwide. Bacterial ghosts are nonliving Gram-negative bacteria devoid of cytoplasmic contents, which induce protective immunity against microbial pathogens. The aims of this study were: a) to produce A. veronii ghost (AVG) constructed by PhiX174 gene E; b) to evaluate the specific, non-specific immune effects and protective immunity of AVG against A. veronii in koi. The lysis plasmid pBBR-E was constructed by cloning PhiX174 gene E into the broad-host-range vector pBBR1MCS2, and then transformed into A. veronii 7231. AVG was generated by increasing the incubation temperature up to 42 °C. Lysis of A. veronii occurred 3 h after temperature induction and completed in 12 h. The efficiency of ghost induction was 99.9998 ± 0.0002%. Koi were immunized intraperitoneally with AVG, formalin-killed bacteria (FKC) or phosphate buffered saline (PBS) respectively, and then respiratory burst (RB), myeloperoxidase (MPO), lysozyme (LZM), malondialdehyde (MDA), complement 3 (C3) and antibody activities were examined in serum. Compared with negative control of PBS, the RB, MPO, LZM activities were significantly higher in koi immunized with AVG (P < 0.05). Nevertheless, the MDA activities of AVG treatment were significantly lower than those of PBS treatment (P < 0.05). The serum agglutination titers and IgM antibody titers in AVG group were significantly higher than those in FKC or PBS groups. After challenged with the parent strain A. veronii 7231, the average mortality of AVG group was significantly lower than that of FKC and PBS groups (P < 0.05) and the relative percent survival (RPS) of AVG group (73.92%) was higher than that of FKC group (43.48%). Therefore, AVG have the potential to induce protective immunity and they may be ideal vaccine candidates against A. veronii in koi.

Occurrence and risk assessment of fluoroquinolones and tetracyclines in cultured fish from a coastal region of northern China

Occurrence and levels of 11 fluoroquinolones (FQs) and four tetracyclines (TC) in 14 cultured fish species from a coastal city in the northern China were investigated. Five FQs (ofloxacin, enoxacin, ciprofloxacin, enrofloxacin, and sarafloxacin) and oxytetracycline were detected. Lower detection frequencies of antibiotics were observed in the marine fish. The concentrations of ΣFQs ranged from not detectable (nd) to 130 ng/g wet weight (ww) (median, 7.2 ng/g ww), and the concentration range of ΣTCs was nd to 200 ng/g ww (median, nd ng/g ww). The Chinese snakehead contained the highest concentrations of ΣFQs (130 ng/g ww) and the small yellow croaker accumulated the highest concentrations of ΣTCs (200 ng/g ww), respectively. Although the calculated estimated daily intakes (EDI) suggested that the consumption of these cultured fish from this region was not associated with significant human health risks, this study provides useful information that will be helpful in the appropriate antibiotic use in aquaculture. To our knowledge, this can be the first report on the occurrence and levels of antibiotics in cage-cultured marine fish from the Bohai Rim region, China.

Antibiotic Pollution in Marine Food Webs in Laizhou Bay, North China: Trophodynamics and Human Exposure Implication

Little information is available about the bioaccumulation and biomagnification of antibiotics in marine food webs. Here, we investigate the levels and trophic transfer of 9 sulfonamide (SA), 5 fluoroquinolone (FQ), and 4 macrolide (ML) antibiotics, as well as trimethoprim in nine invertebrate and ten fish species collected from a marine food web in Laizhou Bay, North China in 2014 and 2015. All the antibiotics were detected in the marine organisms, with SAs and FQs being the most abundant antibiotics. Benthic fish accumulated more SAs than invertebrates and pelagic fish, while invertebrates exhibited higher FQ levels than fish. Generally, SAs and trimethoprim biomagnified in the food web, while the FQs and MLs were biodiluted. Trophic magnification factors (TMF) were 1.2-3.9 for SAs and trimethoprim, 0.3-1.0 for FQs and MLs. Limited biotransformation and relatively high assimilation efficiencies are the likely reasons for the biomagnification of SAs. The pH dependent distribution coefficients (log D) but not the lipophilicity (log K_OW) of SAs and FQs had a significant correlation (r = 0.73; p < 0.05) with their TMFs. Although the calculated estimated daily intakes (EDI) for antibiotics suggest that consumption of seafood from Laizhou Bay is not associated with significant human health risks, this study provides important insights into the guidance of risk management of antibiotics.

Total Diet Study: For a Closer-to-real Estimate of Dietary Exposure to Chemical Substances

Recent amendment on the Food Sanitation Act in Korea mandated the Minister of Food & Drug Safety to secure the scientific basis for management and reevaluation of standards and specifications of foods. Especially because the current food safety control is limited within the scope of 'Farm to Market' covering from production to retail in Korea, safety control at the plane of true 'Farm to Fork' scope is urgently needed and should include 'total diet' of population instead of individual food items. Therefore, 'Total Diet Study (TDS)' which provides 'closer-to-real' estimates of exposure to hazardous materials through analysis on table-ready (cooked) samples of foods would be the solution to more comprehensive food safety management, as suggested by World Health Organization and Food and Agriculture Organization of the United Nations. Although the protection of diets from hazards must be considered as one of the most essential public health functions of any country, we may need to revisit the value of foods which has been too much underrated by the meaningless amount of some hazardous materials in Korea. Considering the primary value of foods lies on sustaining life, growth, development, and health promotion of human being, food safety control should be handled not only by the presence or absence of hazardous materials but also by maximizing the value of foods via balancing with the preservation of beneficial components in foods embracing total diet. In this regard, this article aims to provide an overview on TDS by describing procedures involved except chemical analysis which is beyond our scope. Also, details on the ongoing TDS in Korea are provided as an example. Although TDS itself might not be of keen interest for most readers, it is the main user of the safety reference values resulted from toxicological research in the public health perspective.

Reconnaissance of 47 antibiotics and associated microbial risks in seafood sold in the United States

Aquaculture production has nearly tripled in the last two decades, bringing with it a significant increase in the use of antibiotics. Using liquid chromatography/tandem mass spectrometry (LC-MS/MS), the presence of 47 antibiotics was investigated in U.S. purchased shrimp, salmon, catfish, trout, tilapia, and swai originating from 11 different countries. All samples (n=27) complied with U.S. FDA regulations and five antibiotics were detected above the limits of detection: oxytetracycline (in wild shrimp, 7.7ng/g of fresh weight; farmed tilapia, 2.7; farmed salmon, 8.6; farmed trout with spinal deformities, 3.9), 4-epioxytetracycline (farmed salmon, 4.1), sulfadimethoxine (farmed shrimp, 0.3), ormetoprim (farmed salmon, 0.5), and virginiamycin (farmed salmon marketed as antibiotic-free, 5.2). A literature review showed that sub-regulatory levels of antibiotics, as found here, can promote resistance development; publications linking aquaculture to this have increased more than 8-fold from 1991 to 2013. Although this study was limited in size and employed sample pooling, it represents the largest reconnaissance of antibiotics in U.S. seafood to date, providing data on previously unmonitored antibiotics and on farmed trout with spinal deformities. Results indicate low levels of antibiotic residues and general compliance with U.S. regulations. The potential for development of microbial drug resistance was identified as a key concern and research priority.

Fluoroquinolone antibiotics: an emerging class of environmental micropollutants

The aim of this review paper is to provide a comprehensive overview of different chemical and environmental aspects concerning fluoroquinolone antibiotics as emerging contaminants. A literature survey has been performed based on 204 papers from 1998 to mid-2013, resulting in a dataset consisting out of 4100 data points related to physical-chemical properties, environmental occurrence, removal efficiencies, and ecotoxicological data. In a first part, an overview is given on relevant physical-chemical parameters to better understand the behavior of fluoroquinolones during wastewater treatment and in the environment. Secondly, the route of these antibiotics after their application in both human and veterinary surroundings is discussed. Thirdly, the occurrence of fluoroquinolone residues is discussed for different environmental matrices. The final part of this review provides a tentative risk assessment of fluoroquinolone compounds and their transformation products in surface waters by means of hazard quotients. Overall, this review shows that fluoroquinolone antibiotics have a wide spread use and that their behavior during wastewater treatment is complex with an incomplete removal. As a result, it is observed that these biorecalcitrant compounds are present in different environmental matrices at potentially hazardous concentrations for the aquatic environment. The latter calls for actions on both the consumption as well as the wastewater treatment aspect to diminish the discharge of these biological active compounds.

TDS exposure project: relevance of the total diet study approach for different groups of substances

A method to validate the relevance of the Total Diet Study (TDS) approach for different types of substances is described. As a first step, a list of >2800 chemicals classified into eight main groups of relevance for food safety (natural components, environmental contaminants, substances intentionally added to foods, residues, naturally occurring contaminants, process contaminants, contaminants from packaging and food contact materials, other substances) has been established. The appropriateness of the TDS approach for the different substance groups has then been considered with regard to the three essential principles of a TDS: representativeness of the whole diet, pooling of foods and food analyzed as consumed. Four criteria were considered for that purpose (i) the substance has to be present in a significant part of the diet or predominantly present in specific food groups, (ii) a robust analytical method has to be available to determine it in potential contributors to the dietary exposure of the population, and (iii) the dilution impact of pooling and (iv) the impact of everyday food preparation methods on the concentration of the substance are assessed. For most of the substances the TDS approach appeared to be relevant and any precautions to be taken are outlined.

Trends in monitoring residues of pharmacologically active group B substances in products of animal origin in Lithuania from 1999 to 2008

Monitoring data of group B pharmacologically active substances in the Republic of Lithuania during the period 1999-2008 are presented. Peer review is based on data taken from residue-monitoring plans of the years 1999-2008 and the National Food and Veterinary Risk Assessment Institute reports on analyses performed in various foods. The data were analysed with the SPSS statistical package. Analysis of group B pharmacologically active substances residues monitoring results from the years 1999-2008 revealed that 25,030 samples were tested to detect 421 (1.68%) non-compliant samples in three groups of substances: antibacterials, anthelmintics and non-steroidal anti-inflammatory drugs. Most residues (88.3%) were found in milk, and were far less in beef, pork, sheep and goat meat.

Residues of fluoroquinolones in marine aquaculture environment of the Pearl River Delta, South China

Concentrations and distributions of selected fluoroquinolones (norfloxacin, ciprofloxacin and enrofloxacin) in water, sediments and nine kinds of fish species collected from 6 sites in two marine aquaculture regions of the Pearl River Delta, China, were analyzed by using high-performance liquid chromatography with fluorescence detector (HPLC). The results showed that the concentrations of ciprofloxacin and enrofloxacin were below the limits of quantification (LOQ) in all water samples except for norfloxacin. Norfloxacin and ciprofloxacin concentrations ranged from 1.88 to 11.20 ng g(-1) dry wt, 0.76-2.42 ng g(-1) dry wt in sediments collected from the Dapeng'ao region (sites 1-3) and ranged from 2.31 to 4.75 ng g(-1) dry wt, 1.26-1.76 ng g(-1) dry wt in sediments collected from the Hailing Island region (sites 4-6), respectively. However, no enrofloxacin was found in all sediment samples. The three fluoroquinolones (FQs) were detected in all fish samples, and the concentrations were higher in liver tissues than those in muscle tissues. The levels of norfloxacin were higher than ciprofloxacin and enrofloxacin in both liver and muscle tissues. Among the nine marine fish species, Siganus fuscescens from Hailing Island had a significantly high level of norfloxacin in liver tissue (254.58 ng g(-1) wet wt), followed by Sparus macrocephalus (133.15 ng g(-1) wet wt) from Dapeng'ao, and the lowest value was Lutianus argentimaculatus (5.18 ng g(-1) wet wt) from Hailing Island. The obtained results of FQs in present study do not represent a risk to the human health in Guangdong coastal area, based on the maximum residue limits (MRLs) established by Chinese Government and the acceptable daily intake (ADI) recommended by the Food and Agriculture Organization and World Health Organization (FAO/WHO).

Veterinary drug residues in seafood inspected by the European Union, United States, Canada, and Japan from 2000 to 2009

Veterinary drugs are used to treat or prevent a wide array of production-related diseases in aquaculture. Residues of these drugs in seafood products may pose risks to consumers, prompting governments to set drug residue tolerance levels and inspect seafood for violations of these standards. This study characterizes veterinary drug inspection policies and violations among four inspecting bodies (European Union (E.U.), United States (U.S.), Canada, and Japan), using government-collected veterinary drug violation data from 2000 to 2009. Most veterinary drug violations were detected in species that are commonly farm-raised. Asian seafood products, including shrimp and prawns, catfish (or fish sold as catfish), crab, tilapia, eel, and Chilean salmon were most frequently in violation of veterinary drug residue standards. Vietnam had the greatest number of violations among exporting countries. Concentrations of most veterinary drugs in seafood found in violation did not differ between inspecting bodies that reported drug concentrations. Transparency in seafood inspection reporting varied widely among inspecting bodies. Estimation of violations in the untested fraction of seafood was precluded by a lack of information from inspecting bodies regarding the distinction between targeted and random sampling. Increased transparency could facilitate a more rigorous characterization of public health risks from consuming imported seafood.

Determination of fluoroquinolones in aquaculture products by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)

An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of fluoroquinolones-ciprofloxacin (CIPRO), danofloxacin (DANO), enrofloxacin (ENRO) and sarafloxacin (SARA)-in aquaculture products, specifically salmon, shrimp and tilapia. After initial sample extraction with an acidic acetonitrile solution, the extract was diluted with dichloromethane and centrifuged, then an aliquot was concentrated and applied to a C18 solid-phase extraction cartridge and concentrated for a second time. The resultant residue was dissolved in acetonitrile, diluted with water, and then further defatted with hexane. The fluoroquinolone residues were determined by UPLC with an HSS T3 C18 reverse-phase column using an ammonium hydroxide-formic acid buffer in an acetonitrile gradient with MS/MS detection using multiple reaction monitoring. Average recoveries for salmon tissue ranged from 73% for DANO to 95% for SARA, for shrimp from 71% for DANO to 109% for SARA, and from 62% for DANO to 111% for SARA in tilapia, fortified at the 1.0 ng g(-1) level. Standard curves were linear between 0.002 and 0.5 ng injected for all compounds. Detection limits of 0.2 ng g(-1) for CIPRO, DANO, ENRO, and SARA were easily obtainable. The operational errors, interferences, and recoveries for fortified samples demonstrate that this described method is suitable for routine use in a regulatory programme. The recommended method is simple, rapid, specific and reliable for the routine monitoring of fluoroquinolone residues in aquatic species such as salmon, tilapia and shrimp.