Residues In Meat Research Articles

Evaluating the applicability of the modified four-plate test on the determination of antimicrobial agent residues in pork

The antibiotic residues in 1,022 pork carcass samples, which were collected from 19 areas in Taipei, Taichung and Kaohsiung counties between January and June, 1997, were systematically investigated using a modified four-plate test (MFPT). Four culture media inoculated with 3 strains of bacteria were used; two were inoculated with Bacillus subtilis at pH 6.0 and pH 8.0, and the third and fourth were inoculated with Bacillus cereus and Sarcina lutea, respectively. The identification and quantification of tetracycline residues in the raw meat was performed by bioassay and bioautography. Streptomycin and chloramphenicol in pork carcasses were screened by ELISA and further quantified using the HPLC method. Results showed that using the CNS 5916 method, only 1 out of 1,022 test samples (0.1%) was detected to contain an antimicrobial agent. While using the MFPT method, 4.11% and 0.64% test samples were found to contain tetracycline and streptomycin residues, respectively. No chloramphenicol residue was detected in any tested samples. It was concluded that the MFPT method is practical, sensitive, less expensive, and simple as compared to the CNS 5916 and FPT methods, which are routinely used in Taiwan and the European Community, respectively. MFTP is therefore recommended as an official method to assay the antimicrobial agents in foods.

Validated Stability Indicating Chromatographic Methods for Quantification of Imidocarb Dipropionate; Application for the Determination of Its Residues in Bovine Meat and Milk Samples.

Imidocarb dipropionate (IMD) is an immunomodulator agent commonly used for treatment of anaplasmosis in cattle. Thus, two sensitive, specific, and precise stability-indicating chromatographic methods have been developed, optimized, and validated for its determination in presence of its acid, alkaline, and oxidative stressed degradation products. The first method is based on separation of IMD and its forced induced degradation products on reversed phase cyano column using isocratic elution system consisted of sodium acetate buffer-methanol-acetonitrile (55: 30:15, v/v/v), pH 4.6 at a flow rate of 1.2 mL/min, and UV detection at 254 nm. The second method utilized TLC combined with densitometric determination of the separated bands at 254 nm. The separation was achieved using silica gel 60 F254 TLC plates with a mixture of ethyl acetate-methanol-ammonia-water (8.5:1:0.5:0.2, v/v/v/v) as a developing system. HPLC analysis was applied in range of 0.25-40 µg/mL with LOD of 0.073 µg/mL. While densitometric measurements showed linearity in the range of 0.1-1.8 µg/band with LOD of 0.02 µg/band. The suggested methods were validated in compliance with the ICH guidelines and were successfully applied for determination of IMD in its commercial veterinary formulations with good recoveries. Furthermore, the proposed HPLC method was extended to the determination of IMD residues in bovine meat and milk samples. Bovine meat, HPLC, Imidocarb dipropionate, Milk, TLC.

Study of the antibiotic residues in poultry meat in some of the EU countries and selection of the best compositions of lactic acid bacteria and essential oils against Salmonella enterica

In this study, the presence of antibiotics (ANB) residues was evaluated in poultry meat purchased from German and Lithuanian markets. In addition, the antimicrobial activity of 13 lactic acid bacteria (LAB) strains, 2 essential oils (EO) (Thymus vulgaris and Origanum vulgare L.), and their compositions were tested for the purpose of inhibiting antibiotic-resistant Salmonella spp. ANB residues were found in 3 out of the 20 analyzed poultry meat samples: sample no. 8 contained enrofloxacin (0.46 μg/kg), sample no. 14 contained both enrofloxacin and doxycycline (0.05 and 16.8 μg/kg, respectively), and sample no. 18 contained enrofloxacin (2.06 μg/kg). The maximum residue limits (MRLs) for the sum of enrofloxacin and ciprofloxacin and for doxycycline in the poultry muscle are 100 μg/kg. Finally, none of the tested poultry meat samples exceeded the suggested MRLs; however, the issue of ANB residues still requires monitoring of the poultry industry in Germany, Poland, and Lithuania, despite the currently established low ANB concentrations. These findings can be explained by the increased use of alternatives to ANB in the poultry industry. Our results showed that an effective alternative to ANB, which can help to reduce the occurrence of antibiotic-resistant salmonella, is a composition containing 1.0% of thyme EO and the following LAB strains: Lactobacillus plantrum LUHS122, Enteroccocus pseudoavium LUHS242, Lactobacillus casei LUHS210, Lactobacillus paracasei LUHS244, Lactobacillus plantarum LUHS135, Lactobacillus coryniformins LUHS71, and Lactobacillus uvarum LUHS245, which can be recommended for poultry industry as components of feed or for the treatment of surfaces, to control the contamination with Salmonella strains. However, it should be mentioned that most of the tested LAB strains were inhibited by thyme EO at the concentrations of 0.5 and 1.0%, except for LUHS122, LUHS210, and LUHS245. Finally, it can be noted that the agents responsible for the inhibitory effect on Salmonella are not the viable LAB strains but rather their metabolites, and further studies are needed to identify which metabolites are the most important.

Identification and quantification of antimicrobial activity in commercially available chicken meat in a large urban centre in Pakistan

BackgroundLarge-scale use and misuse of antibacterial agents for infection prevention and growth promotion in chicken has grown alongside mass production of poultry as a primary protein source in human diet. This has led to concern about promotion of antibiotic resistance among bacteria of clinical significance to human disease. The objectives of this study are to identify which, if any, antimicrobials are commonly found in commercially available broiler chicken and determining the minimum amount of meat with enough microbial inhibitory activity that can be measured in routine culture. Four test organisms, namely ATCC 25922, ATCC 51299, clinical isolate MRSA and clinical isolate E. coli were used. The antimicrobial sensitivity profiles of the test organisms were determined against beta-lactams, tetracyclines, aminoglycosides, sulphonamides, fluoroquinolones and phenicols. 8 mm tissue pieces of liver, muscle and kidney samples were obtained and plated on all four plates of our test organisms. The zones of inhibition, if any, around the tissue samples determined the presence of antimicrobial residues in meat. 270 tissue samples of liver, muscle and kidney were tested for the presence of antimicrobial residues. In total 90 freshly butchered broiler chicken samples were collected, each contributing a liver, kidney and a muscle tissue sample. The samples were collected randomly from butcher shops across geographical bins of the city of Lahore.The results showed that 73.3% of the samples were positive for antimicrobial activity. Of these 69.6% of the samples were positive for the presence of sulfonamides, 9.3% had flurphenicol, 7.0% had quinolone activity, 6.7% had aminoglycoside activity and 3.7% had tetracyclines in them.

Rapid, simple and green solid phase extraction based on polyaniline nanofibers-mat for detecting non-steroidal anti-inflammatory drug residues in animal-origin food

In this study, polyaniline modified polyacrylonitrile nanofibers mat (PANI NFsM) was prepared as a novel adsorbent for the solid-phase extraction (SPE) of non-steroidal anti-inflammatory drug residues in meat or egg samples. The solvent extracts of samples were simply diluted with water to perform the SPE, and then the eluent was directly analyzed. Significant reduction of the matrix effect was obtained after SPE using only 5 mg of PANI NFsM. The entire sample preparation time is 5–10 times lower than the existing methods. The limits of detection of the target analytes ranging from 0.6 to 12.2 µg kg−1 had already met the demand of food safety monitoring by only 1 g sample. The recoveries ranged from 85.18% to 107.31%, with the intra-day and inter-day relative standard deviations of 2.74% to 16.01%, revealing satisfactory accuracy and precision. Finally, real samples analyses were applied to verify the practicability of the method.

Effective screening of antibiotic and coccidiostat residues in food of animal origin by reliable broad-spectrum residue screening tests

Foods of animal origin are controlled for antibiotic and coccidiostat residues. The rapid residue detection is possible using reliable broad-spectrum screening tests. This study’s objective using four microbial inhibition tests for the detection and identification of antibiotic and coccidiostat residues in different foods of animal origin: Premi®Test, EXP Ampulle test, Milchtest and Screening Test for Antibiotic Residues (STAR). Four hundred and thirty (430) food samples (165 animal tissues, 152 raw cow’s milk and 113 eggs) were randomly collected and screened. Using the Premi®Test, 18 samples were positive and 6 samples dubious. Using the EXP Ampulle test, 31 samples were positive and 2 samples dubious. Using the Milchtest, 15 samples were positive and 12 samples dubious. Using the STAR, 65 samples were positive with 62 samples positive on plates specific for beta-lactams and sulphonamides, 4 samples on plates specific for aminoglycosides, 8 samples on plates specific for macrolides and beta-lactams; and 7 samples on the plates specific for tetracyclines. Retesting using penicillinase and para-aminobenzoic acid (PABA) to confirm the presence of beta-lactams or sulphonamides all potentially positive tube test samples revealed 21 samples positive for beta-lactams and 27 samples positive for sulphonamides. Further testing of sulphonamide positive chicken samples revealed the positivity for coccidiostat salinomycin which was confirmed by testing with PABA, which counteracting salinomycin inhibition. Three hundred and sixty six (366) animal food samples were negative for antibiotic and coccidiostat residues. Microbial inhibition tests are preferred for initial antibiotic screening and have also proven useful for coccidiostat screening and post-screening. HIGHLIGHTS Foodstuffs of animal origin are subject to controls on antibiotic and coccidiostat residues. Microbial inhibition tests are still the preferred choice for the initial screening of antibiotic residues in food matrices and could become a useful tool for the screening of coccidiostat residues also. More specific post-screening analysis with PABA proved unexpectedly to be a reliable tool in the preliminary detection of coccidiostat residues in poultry meat and eggs.

Veterinary antimicrobial residues in pork meat in Cyprus: An exposure assessment

This work provides original analytical data on the levels of 45 commonly used veterinary antimicrobials in raw pork meat samples in Cyprus for six consecutive years between 2012 and 2017. A total of 15,484 raw pork meat samples were collected and screened for antibiotic residues by a microbiological screening method. A total of 1766 samples which were found suspected positive for antimicrobial residues were analyzed by means of a tandem LC–MS/MS confirmatory method. Thirteen veterinary antimicrobials were detected in 596 positive samples, with a detection frequency of 3.8% and nine antimicrobials exceeded the Maximum Residue Limits. The estimated daily exposure dose was found to be less than 1.8 μg/kg/day for all the compounds in both men and women above twenty years of age. These findings suggest that raw pork meat, do not present a potential health risk through its consumption in Cyprus.

Application of Mangosteen Peel Extract (Garcinia mangostana L) As Feed Additive in Ration for Performance production and Egg Quality of Sentul Chicken

Sentul chicken is a specific local chicken from the Ciamis region in West Java and a dual-purpose type that can be utilized for eggs and meat production. The use of antibiotics continuously for maintenance to prevent and treat disease in Sentul chicken can lead residues in meat and eggs. To wean farmers for the antibiotic, it is necessary to find a natural antibiotic derived from herbal plants that Mangosteen Peel Extract (MPE). Mangosteen Peel Extract (MPE) is containing xanthone compounds like antioxidants and antimicrobials. This research was held to find out the effect of mangosteen peel extract on feed consumption, hen day production, feed conversion, and egg quality. This research used 40 female chickens aged seven months, which was kept in cages until three months, and each cage contains 2 chickens. The method used was a completely randomized design with four treatments namely P0 (ration without MPE), P1 (ration with 67 ml/kg MPE addition), P2 (addition of 100 ml/kg MPE) and P3 (addition of 133 ml/kg MPE) with five replications. Furthermore, treatment differences were tested using Duncan Multiple Range Test. The measured variables were feed consumption, egg weight, hen day production, feed conversion, thick of shell, egg yolk color, and egg cholesterol. The results showed the addition of MPE 133 ml/kg ration had a significant effect on egg production, egg weight, feed conversion, the thickness of eggshell, the color of egg yolk, and egg cholesterol but not significant to feed consumption, yolk index score and Haugh unit. It can be concluded that MPE can be used as a feed additive until 133 ml/kg ration to gave the best on production and egg quality of Sentul chicken.

Risk of multi-drug resistant Campylobacter spp. and residual antimicrobials at poultry farms and live bird markets in Bangladesh

BackgroundUnderstanding potential risks of multi-drug resistant (MDR) pathogens from the booming poultry sector is a crucial public health concern. Campylobacter spp. are among the most important zoonotic pathogens associated with MDR infections in poultry and human. This study systematically examined potential risks and associated socio-environmental factors of MDR Campylobacter spp. in poultry farms and live bird markets (LBMs) of Bangladesh.MethodsMicrobial culture and PCR-based methods were applied to examine the occurrence and MDR patterns of Campylobacter spp. in potential sources (n = 224) at 7 hatcheries, 9 broiler farms and 4 LBMs in three sub-districts. Antimicrobial residues in broiler meat and liver samples (n = 50) were detected by advanced chromatographic techniques. A questionnaire based cross-sectional survey was conducted on socio-environmental factors.ResultsOverall, 32% (71/ 224) samples were found contaminated with Campylobacter spp. In poultry farms, Campylobacter spp. was primarily found in cloacal swab (21/49, 43%), followed by drinking water (8/24, 33%), and meat (8/28, 29%) samples of broilers. Remarkably, at LBMs, Campylobacter spp. was detected in higher prevalence (p < 0.05) in broiler meat (14/26, 54%), which could be related (p < 0.01) to bacterial contamination of drinking water (11/21, 52%) and floor (9/21, 43%). Campylobacter isolates, one from each of 71 positive samples, were differentiated into Campylobacter jejuni (66%) and Campylobacter coli (34%). Alarmingly, 49 and 42% strains of C. jejuni and C. coli, respectively, were observed as MDR, i.e., resistant to three or more antimicrobials, including, tetracycline, amoxicillin, streptomycin, fluoroquinolones, and macrolides. Residual antimicrobials (oxytetracycline, ciprofloxacin and enrofloxacin) were detected in majority of broiler liver (79%) and meat (62%) samples, among which 33 and 19%, respectively, had concentration above acceptable limit. Inadequate personal and environmental hygiene, unscrupulously use of antimicrobials, improper waste disposal, and lack of health surveillance were distinguishable risk factors, with local diversity and compound influences on MDR pathogens.ConclusionPotential contamination sources and anthropogenic factors associated with the alarming occurrence of MDR Campylobacter, noted in this study, would aid in developing interventions to minimize the increasing risks of poultry-associated MDR pathogens under ‘One Health’ banner that includes poultry, human and environment perspectives.

Rapid Detection of Tetracycline Residues in Chicken

Antibiotic residues in meat are a serious public health concern as a result of its harmful effects on consumer health. This study aimed at estimating the residues levels of commonly used antibiotics (Tetracycline) in chicken samples using two analytical methods; Rapid Screening Kit and HPLC.&#x0D; Twenty chicken samples were collected from various meat shops of Kathmandu valley. Qualitative and semi-quantitative analyses with Quicking Tetracycline rapid Test kit, which detect tetracycline above 100 ppb in tissue revealed that two samples were positive for antibiotic residues in the chicken for tetracycline. The concentration of residues of tetracycline, which were positive in rapid test kit was quantified by high-performance liquid chromatography equipped with a UV detector (HPLC-UV). One muscle sample and one liver sample of chicken have found the concentration of tetracycline as 229 and 339 μg/kg, respectively while chlortetracycline was not detected. This result confirmed widespread misuses of antibiotics especially tetracycline in farm and lack of application of recommended withdrawal times. Antimicrobial assay of chicken extracts was also performed by using the disc-diffusion agar method.The plates were incubated overnight at 37 °C for 18-24 hours, butmicrobial growthwas not observed in all the samples tested.&#x0D; Int. J. Appl. Sci. Biotechnol. Vol 8(1): 14-20

Screening of Antimicrobial Residues and Confirmation of Doxycycline in Samples Collected from Chicken Farms and Processing Units Located Around Mumbai, India

The presence of antimicrobial residues in meat has several impacts on health aspects to the consumer. Strategic and scientific study on risk assessment of antibiotic residue in poultry production chain with different set of practices has not been conducted in order to protect the health of common consumers. The present study was planned to screen antibiotic residue in chicken meat production chain managed under different set of practices of farming and processing. Chicken farms managed under non-integrated, partially integrated and completely integrated sector and three different individual chicken processing units identified as retail shops, semi-automatic processing unit and automated processing unit along with one product processing unit were randomly selected for the collection of samples. A total of 271 samples (meat, serum, water and feed) comprising of 180 samples from poultry farms, 81 samples from chicken processing units and 10 muscle samples from poultry product processing units were collected and subjected for qualitative antimicrobial screening by Microbial Inhibition Assay Test Kit and confirmation by High Performance Liquid Chromatography /Liquid Chromatography Mass Spectrometry was done. On screening by Microbial Inhibition Assay Test Kit, Muscle (2), Liver (2) and Feed (7) samples (6.11%) were positive from non-integrated (3.88%) and partially integrated farming systems (2.22%). Significant difference (P less than 0.05) was observed for antibiotic residue in feed samples of non-integrated (55.55%) and partially integrated (22.22%) farms. On screening of 91 samples, collected from chicken processing and product processing units, 08 (8.79%) samples were -positive. The HPLC analysis indicated that 9.5% and 5.26% muscle and liver samples, respectively were positive for doxycycline residue. Feed samples (57.14%) found positive to Chlortetracycline and 4-Epichlorotetracycline residues when analyzed by LCMS, with mean concentration of 2722.12 and 3720.87µg/kg, respectively. The presence of antibiotic residues in muscle and liver samples of unorganized farms and retail processing unit was higher in comparison. Therefore, the poultry farming and processing systems should be kept under continuous monitoring for preventing the occurrence of antibiotic residues in meat and meat products.

Biomonitoring of the hematological, biochemical and genotoxic effects of the mixture cypermethrin plus chlorpyrifos applications in bovines

External antiparasitic agents applied in bovine production represent a risk to consumers of meat products, especially if the conditions of their use are not strictly respected. The post-mortem control of residues in meat is an activity that must be updated and reinforced by the biomonitoring of live animals and the use of analytical tools to help identifying signs of early warning risks. The objective of the present study was to carry out a pre-slaughter biomonitoring approach in Aberdeen Angus cattle and crosses (n = 12) with the application of a commercial formulation of cypermethrin plus chlorpyrifos. This was performed with a single therapeutic dose applied on the backs of the cattle, through hematological, enzymatic, as well as hepatic and renal function analysis in plasma, and then quantifying the genotoxic effect on lymphocytes. Analytical measurements of plasma concentrations of cypermethrin plus chlorpyrifos at 24 h were negative and therefore a low absorption of the compounds was assumed. Measurement of acetyl cholinesterase showed no inhibition after exposure. The concentration of urea increased between 24 h and 168 h post application of the formulation, without showing any kidney damage. The rest of the parameters analyzed did not show any variations. This evaluation of hematological and biochemical effects and of cytokinesis-block micronucleus cytome assay in bovines is proposed as a pre-slaughter control of biomonitoring of the health status of animals, with a focus on food safety for meat consumers.

HEALTH RISKS ASSOCIATED WITH HEAVY METALS IN COMMERCIAL CHICKEN MEAT VIA CONSUMPTION WITHIN SOUTHERN NIGERIA

Chicken meat is classed among one of the major sources of animal proteins and still enjoys global acceptance to date without recourse to their heavy metal residues. Hence, this study investigated the heavy metal residues in raw chicken meat and the associated health risk via consumption within major markets in southern Nigeria. A total of 240 raw chicken meat samples (muscle tissues) were purchased randomly from Warri, Akure, Ado-Ekiti and Benin City markets. After ashing, digestion and heavy metals analysis for Pb, Cr, Cd, Mn, Ni, Zn and Cu using standard atomic adsorption spectrophotometer, the target hazard quotient (THQ), health risk index (HI) and daily intake index (non-carcinogenic risk) and incremental cancer risk in children and adults were determined. The mean heavy metals ranged from 0.001 ± 0.001 mg/kg (Cr) to 2.094 ± 0.001 mg/kg (Zn) and varied significantly (P&lt;0.05) with Warri samples (58.9 %) yielding the highest level, followed by Benin City (26.8 %), Ado-Ekiti (10.2 %) and Akure (4.2 %) samples. The non-carcinogenic risks (HR/HI) were substantially low for the metals studied in all the locations except for Cd, which could pose serious health risk among children in Warri location. However, the incremental cancer risk ranged from 10-4 to 10-3 in all the locations, suggesting at least a cancer case per 1,000 exposed people (both in children and adults). Considering the impending public health risks, critical hazards points of heavy metals contaminations along meat production chains should be properly identified to drastically reduce their potential risks to exposed consumers.

Investigation of zeranol in beef of Ukrainian production and its reduction with various technological processing

Synthetic growth stimulants are widely used to get high productivity of animals. These preparations can accumulate in the meat and their residual quantities will adversely affect the health of consumers. The purpose of the work was to monitor the content of zeranol, growth stimulant of ruminants in beef which goes to meat processing enterprises of the Western region of Ukraine and to determine the effect of heat treatment on its quantity. It was found out that 29.8% of beef samples taken at meat processing enterprises contained a stimulant for the growth of ruminant zeranol. It was found that during the storage of beef samples frozen at a temperature of -18 °C with different content of zeranol there is a decrease in its number. The most intense process of destruction of zeranol occurred during the first month of storage, during this period of time the amount of zeranol is reduced by an average of 20%, regardless of the initial content. Within two months of storage of frozen beef, the content of zeranol decreases by 28.2 ±0.17%, and at the end of the sixth month its quantity decreases to 33.2 ±0.58%. It was also found that the dynamics of zeranol reducing in beef samples with large quantities (22.5 μg.kg-1) and small (2.3 μg.kg-1) were the same. It was set up that during 30 min of meat cooking there was a decrease in the content of zeranol 24.7 ±0.23% and 32.0 ±0.35% for 60 min, compared to its content in fresh meat. At the same time, when stored in the frozen state and subsequent cooking, the reduction of zeranol content in meat was 39.3 ±0.3%. Therefore, it is proposed to revise and amendments into the regulatory documents of Ukraine regarding the control and supervision of the presence of hormone (zeranol) residues in meat and meat products in order to prevent their sale and consumption by humans.

Emerging food safety risk of hepatotoxic indospicine in feral Australian camel meat

Indospicine is a hepatotoxic non-proteinogenic amino acid that has only been found in Indigofera plants including a number of species abundant in central Australia. These legumes are palatable to feral camels and indospicine residues derived from these plants accumulates in camel meat tissue. Indospicine-contaminated camel meat has caused liver disease and mortalities in dogs after a short period of dietary exposure. Since camel meat is also exported for human consumption, this raises concern about the human health risks of consuming indospicine-contaminated camel meat harvested from central Australia. The objective of this study was to assess the indospicine levels in camel meat and its associated potential health risk to the Australian population and the vulnerable sub-population of indigenous Australians from the consumption of such feral camel meat. Two main quantitative probabilistic exposure assessments were conducted through the use of Monte Carlo simulations. The first exposure assessment considered the indospicine concentrations in real-field camel meat samples. The second assessment was based on a simulated probabilistic distribution of indospicine residues in camel meat, involving eight (8) predictive factors that were derived from our published research data and other secondary sources. The first assessment predicted that the estimated risk of developing indospicine₋induced hepatotoxicosis from contaminated camel meat consumption was 800 per 10 000 of the average Australian population (8.0%), and higher for the indigenous Australians (10.0%). The second exposure assessment demonstrated there was a higher risk (>31%) for the whole Australian population and for the indigenous Australian population. In conclusion, this risk assessment study shows that, while there is a low risk amongst Australians of hepatotoxicosis being associated with the consumption of indospicine-contaminated camel meat, such consumption is still a cause for concern, since the assessment based on the simulated probabilistic distribution of indospicine concentrations in camel meat demonstrated a substantially higher risk. It is therefore advisable that an indospicine residue monitoring program should be implemented to ensure food safety of Australian camel meat. Additionally, the risk of dietary indospicine exposure from other livestock grazing Indigofera in all global regions should also be considered.

Hapten Synthesis and the Development of an Ultrasensitive Indirect Competitive ELISA for the Determination of\xa0Diethylstilbestrol in Food Samples

An ultrasensitive indirect competitive enzyme-linked immunosorbent assay (ic ELISA) using monoclonal antibodies (mAbs) was developed for the specific detection of diethylstilbestrol (DES) residues. To establish an ELISA based on mAbs, hapten diethylstilbestrol mono-carboxypropyl-ether (DES-MCPE) was chemically synthetized and then conjugated to bovine serum albumin (BSA) for immunization in mice. This ic ELISA was further optimized for DES determination. The sensitivity of the ic ELISA was found to be 0.49 μg/kg and the limit of detection was 0.075 μg/kg. DES residues in salmon meat and pork were tested with the recovery range from 74.0 to 85.2% and the coefficient of variation (CV) was less than 10%. Parallel analysis of DES samples from salmon meat showed comparable results from the ic ELISA with high-performance liquid chromatography. The ic ELISA provides a useful screening method for the quantitative detection of DES residues in animal-derived food.

Dual-layer column filtration cleanup and gas chromatography-tandem mass spectrometry detection for the analysis of 39 pesticide residues in porcine meat.

A rapid and effective method was developed for the analysis of 39 pesticide residues in porcine meat with dual-layer multiplug filtration cleanup and gas chromatography-tandem mass spectrometry detection. The cleanup process was performed with columns packed with two layers, namely multiwalled carbon nanotubes, C18 and anhydrous magnesium sulfate (MgSO4 ) as top layer, while mixture of florisil and MgSO4 as bottom layer. A single-layer method was tested in parallel, with columns packed with the same amount of absorbents. Extraction conditions and filtration cleanup process were optimized to obtain satisfied method performance. Method linearity was calculated with coefficients of determination more than 0.995. The limits of quantitation were verified with acceptable accuracy at the lowest spiked concentration of 0.01mg/kg (except pyrimethanil). The recoveries at three fortified levels (0.01, 0.05, and 0.1mg/kg) in five replicates were between 74 and 118% (except pyrimethanil) with relative standard deviations range from 1 to 16%. The matrix effects were in the range of 1.01 to 2.84. This new method was applied for the analysis of multipesticide residues in market samples of porcine meat. This study showed the dual-layer multiplug filtration cleanup demonstrated better performance than that with the single-layer columns in cleanup of porcine meat.

Classification of Sulfadimidine and Sulfapyridine in Duck Meat by Surface Enhanced Raman Spectroscopy Combined with Principal Component Analysis and Support Vector Machine

In order to meet the growing demand for food safety, the rapid classification of sulfadimidine and sulfapyridine in duck meat based on surface-enhanced Raman spectroscopy (SERS) was investigated using gold nanoparticles (Au NPs) and NaCl solution as the active substrate and active agent, respectively. The results showed that the Raman characteristic peaks at 557 and 573 cm−1 were used to determine whether sulfadimidine and sulfapyridine remained in duck meat. A single factor experimental method was used to optimize the conditions. Three pretreatment methods were employed to optimize the raw measurements. According to the classification accuracies, adaptive iterative reweighted penalty least squares and second derivative were selected to be the optimal pretreatment method. Next, principal component analysis (PCA) was performed to extract the characteristic variables. The first four score values of PCA were selected to be the input values of support vector machine (SVM) classification model, which classified duck meat samples into four categories. Nu-support vector classification and radial basis function were selected to be the employed SVM classification model and the Kernel type, respectively. The gamma and nu values were 0.25 and 0.255, respectively. The classification accuracy for the test set was 90.44%. The sensitivities and specificities of test set were calculated, and the highest sensitivity and specificity values were 96.97% and 100%, respectively. The experimental results showed that this classification model provides favorable classification results. Therefore, the adopted method may be used for the rapid classification of sulfadimidine and sulfapyridine residues in duck meat.

The Fabrication of a Highly Sensitive Nano Green Carbon Paste Electrode Modified with Yttrium Doped Manganese Oxide (Mn2O3/Y2O3) for Electrochemical Determination of Marbofloxacin and Its Residues in Bovine Meat and Milk Samples

In the present work, a novel sensitive electrochemical carbon paste electrode chemically modified with yttrium doped manganese oxide Mn2O3/Y2O3 nanostructures was assigned for determination of marbofloxacin (MRB) using square wave voltammetry (SWV) method. MRB has a broad spectrum of bactericidal activity for the treatment of urinary, respiratory and dermatological diseases in bovines and their retention in animal meats and milk leads to adverse side effects for the consumer. Thus a rapid estimation of minor concentrations of MRB has exerted a great concern to ensure food safety. XRD, EDX, Raman spectroscopy, SEM, and TEM techniques were employed to characterize the samples. The electrochemical oxidation behavior of MRB shows irreversible anodic peak at 1.10 V vs Ag/AgCl, in Britton–Robinson buffer (BR) at pH 5.0. The relationship was rectilinear over the range 10 × 10−9–1.0 × 10−4 M between the peak current and its related concentration with a minimum detection limit of 2.4 × 10−9 M. The developed method was green chemistry challenges and successfully applied to assay the drug in its dosage form, bovine meat and milk samples with a good recovery lies between 94.56% and 105.33% with relative standard deviation less than 10%.

Nano Green Voltammetric Determination of Imidocarb Dipropionate and Its Residues in Bovine Meat, Milk and Urine Samples

Imidocarb dipropionate (IMD) is an antimicrobial agent that is widely used in veterinary medicine for treatment of many diseases especially anaplasma marginale in cattle. This may lead to the retention of its residues in edible bovine tissues, milk and urine samples. Thus the quick determination of minor concentrations of IMD is of great interest to ensure food safety. A novel electrochemical sensor was introduced for the sensitive, fast and selective determination of IMD in drug substance and commercial product, furthermore its application to determine IMD residues in bovine meat, milk and urine samples. The prepared nanoparticles sensor was based on a multiwalled carbon nanotube composite modified with gold nanoparticles GNPs/MWCNT. The linear response obtained for IMD using the GNP/MWCNT was found to be over the range of 0.20–3.6 n mol l−1 with a good linearity and high correlation (0.9999). The limits of detection and quantification were found to be 36 p mol l−1 and 109 p mol l−1 respectively. The developed method was simple, rapid, economic, and challenging to green chemistry. The high sensitivity, good reproducibility, and wide linear range mark the modified electrode suitable for determination of the residues in bovine meat and milk as real samples with excellent recoveries.