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1.
The Canadian Food Inspection Agency (CFIA) routinely monitors the Canadian food supply to ensure that the levels of antibiotic residues are below the stated regulatory guidelines. Over a two-year period, both domestic and imported eggs in Canada were analyzed for a number of veterinary drugs. These included chloramphenicol, beta-lactams, fluoroquinolones, halofuginone, macrolides, sulfonamides, tetracyclines, decoquinate, and coccidiostats. More than 99% of the samples screened were found to be free of any veterinary drug residue. The remainder were found to contain tetracyclines, sulfonamides, ciprofloxacin, macrolides, streptomycin, clopidol, ethopabate, and nitromide. Current methods used for the analysis of these residues are discussed.  相似文献   

2.
An analytical method for the identification of the residues from 14 commonly used antibiotics is presented. The technique is based on selective tissue extraction followed by thin layer chromatography (TLC)/bioautography. Antibiotic residues are extracted from the tissues with methanol and methanol-HCl (98 + 2). The methanol extract is further extracted with chloroform to isolate groups of antibiotics. The extracts are spotted onto TLC plates and developed in suitable solvent systems. Developed plates are placed on set medium seeded with Bacillus subtilis and a bioautograph is produced. The locations of zones of inhibition are used to identify antibiotic residues. Recoveries of antibiotics were quantitative, while the effect of naturally inhibiting components of the matrix was minimized. The sensitivity of the method can be adjusted through minor modifications, which allows its use in routine regulatory analysis.  相似文献   

3.
综述了近年来毛细管电泳技术在兽医药品分析中的应用和进展,主要包括抗生素类残留、磺胺类残留、激素及β-兴奋剂类残留等的检测,并对其今后的发展作了展望。  相似文献   

4.
A survey of literature is presented dealing with physical-chemical methods for the detection and quantitation of aminoglycoside antibiotics (gentamicin, streptomycin, dihydrostreptomycin, and neomycin) that are used in food-producing animals. Recent developments in cleanup and determinative procedures, particularly liquid chromatography, for these compounds in fluids and tissues are emphasized. Little research has been done on residues in tissues compared with other biological matrices. This review also covers the chemistry, general characteristics, tolerances, and withdrawal times for the approved uses of these antibiotics in animals that are used for food.  相似文献   

5.
A method was developed that is suitable for screening eggs for a variety of nonpolar residues in a single procedure. Residues are extracted by silica solid-phase extraction (SPE). Analysis is conducted via reverse-phase gradient liquid chromatography, electrospray ionization, and tandem ion trap mass spectrometry. For screening purposes (based on a single precursor-product ion transition) the method can detect ionophore (lasalocid, monensin, salinomycin, narasin) and macrolide (erythromycin, tylosin) residues in egg at approximately 1 ng/mL (ppb) and above and novobiocin residues at approximately 3 ppb and above. Conditions are described for confirmatory analysis based on multiple ions in the product ion spectrum. The extraction efficiency for ionophores was estimated at 60-85%, depending on drug. Recovery of macrolides and novobiocin was not as good (estimated at 40-55% after a hexane wash of the final extract was included), but the method consistently screened and confirmed these residues at concentrations below the target of 10 ppb. The method was applied to eggs from hens dosed with each drug individually. Lasalocid was found to have the highest probability of detection in eggs based on its high ionization efficiency and higher rate of deposition relative to the other drugs. The method is part of a larger scheme to provide surveillance methods for a wide variety of drug residues in eggs.  相似文献   

6.
Methodology for the analysis of 8 benzimidazoles as residues in bovine liver is reported. Spiked tissues were extracted by homogenization in saline and ammonium hydroxide and blending with diatomaceous earth. This matrix was packed into a column, and the benzimidazoles were eluted with ethyl acetate. After the sample was further purified, benzimidazoles were separated and quantitated by liquid chromatography with ultraviolet detection (290 nm). Liver tissue samples obtained from cattle which had undergone a drug depletion study of fenbendazole administered per os were analyzed using these methods. The results of these analyses and the application of this approach to multiresidue analysis of drugs in animal tissues are discussed.  相似文献   

7.
该研究探索并构建一种基于历史数据分析的安全预警方法,对生鲜乳中兽药残留情况进行识别、控制与评价,以便在风险发生之前做出准确判断。首先利用高效液相色谱-高分辨飞行时间串联质谱(High Performance Liquid Chromatography-high Resolution Time-of-flight Tandem Mass Spectrometry,HPLC-TOF-MS/MS)方法对上海市各牧场的生鲜乳进行兽药残留筛查,然后以生鲜乳中泼尼松(Prednisone,Pre)残留检出数为例,利用休哈特控制图(Shewhart control charts)构建风险预警体系。结果表明:在300个生鲜乳样品中共筛查出42种兽药残留,涉及类固醇类(12种)、糖皮质类(6种)和镇静剂(5种)等12大类;在筛查的6个星期中,泼尼松检出数(Number of Prednisone Detected,Pn)控制图呈现稳定的状态;当假设第7周泼尼松检出数为6时,Pn控制图呈现稳态,未触发预警;当假设第7周泼尼松检出数为10时,Pn控制图出现异常,稳态遭到破坏,此时该批样品触发风险预警。综上,利用HPLC-TOF-MS/MS能对生鲜乳样品进行高通量的兽药残留筛查,再利用休哈特控制图结合历史数据可以对生鲜乳样品的兽药残留进行有效的风险监测和预警。  相似文献   

8.
从浙江省杭州、嘉兴和绍兴等3个地级市采集了4种不同施肥方式下(分别为施用畜禽粪+化肥、商品有机肥+化肥、沼渣+化肥和单施化肥)的蔬菜地表层土壤样品44个,分析了4类8种抗生素(包括四环素类抗生素的土霉素、四环素和金霉素,喹诺酮类抗生素的恩诺沙星,磺胺类抗生素的磺胺嘧啶、磺胺二甲嘧啶和磺胺甲噁唑及大环内脂类抗生素的泰乐菌素)的残留情况,探讨了施肥方式对蔬菜地土壤中抗生素残留的影响。结果表明,蔬菜地土壤中抗生素的检出率和残留含量与施肥方式密切相关。8种检测的抗生素中土霉素的检出率和残留含量明显高于其他种类的抗生素,土霉素的平均含量占8种抗生素总量平均值的67.03%。抗生素的检出率和平均含量由高至低依次为:土霉素磺胺二甲嘧啶恩诺沙星四环素磺胺甲噁唑、泰乐菌素金霉素磺胺嘧啶;四环素类抗生素磺胺类抗生素。土壤中各类抗生素的检出率及含量均为施用畜禽粪的蔬菜地施用商品有机肥的蔬菜地施用沼渣的蔬菜地单施化肥的蔬菜地,施用畜禽粪的蔬菜地土壤中抗生素残留量明显高于其他蔬菜地。试验结果表明,畜禽粪是蔬菜地土壤抗生素的主要来源,商品有机肥和沼渣的施用对蔬菜地土壤中抗生素的残留也有一定的贡献。  相似文献   

9.
随着养殖业的迅猛发展,动物源食品兽药残留问题日益成为食品安全领域的重要内容。动物源食品基质复杂,而其中残留的兽药含量甚微,传统的样品制备及检测方法大多存在检测样品基质种类单一、检测兽药种类范围小、耗时长、重现性差等问题,缺乏一定的通用性和准确性,已不能满足当前社会发展的需要。近年来,随着QuChERS法和高分辨质谱等先进样品制备和检测技术在兽药残留检测分析领域的应用,一批高通量、自动化乃至可视化的快速高效分析检测方法也随之而起,该文即对这些高通量快速样品制备和检测方法进行综述,同时对动物源食品中兽药残留的检测和监控等工作提出建议并进行了展望。  相似文献   

10.
The technique of immunochemical analysis, including the principles involved, is described and the various types of assay are discussed. Application of these methods to the analysis of foods for residues of pesticides, contaminants, drug residues, and natural constituents is reviewed. Compared with conventional methods, immunoassays offer similar detection limits and greatly simplified sample preparation procedures.  相似文献   

11.
Veterinary drugs and feed additives (especially some coccidiostats) can be absorbed by the digestive tract of laying hens and transferred to the egg. Physicochemical characteristics of these compounds determine their pharmacokinetic behavior and distribution to and within the egg. Traditionally the quite lipid soluble drugs and additives are expected to yield residues only in the fat-rich yolk. However, the quite lipid soluble drug doxycycline--as well as many other drugs--showed during long-term administration higher residues in white than in yolk. In a model study with 11 sulfonamides differing in pK(a) value and lipid solubility, their distribution in vivo between yolk and white was determined. Neither differences in pK(a) values nor those in lipid solubility could explain the distributions found. Binding to egg white macromolecules in vivo as an explanatory factor was tested with five sulfonamides, and no correlation between binding and the distribution of sulfonamides between white and yolk was found. Literature data on the distribution of drugs between egg white and yolk showed a reasonable consistency within drugs and a large variability among drugs (as could be expected). This larger database also did not provide a clue as to what factor determines the distribution of a drug between egg white and yolk when given to laying hens.  相似文献   

12.
A method was developed for detection of a variety of polar drug residues in eggs via liquid chromatography/tandem mass spectrometry (LC/MS/MS) with electrospray ionization (ESI). A total of twenty-nine target analytes from four drug classes-sulfonamides, tetracyclines, fluoroquinolones, and beta-lactams-were extracted from eggs using a hydrophilic-lipophilic balance polymer solid-phase extraction (SPE) cartridge. The extraction technique was developed for use at a target concentration of 100 ng/mL (ppb), and it was applied to eggs containing incurred residues from dosed laying hens. The ESI source was tuned using a single, generic set of tuning parameters, and analytes were separated with a phenyl-bonded silica cartridge column using an LC gradient. In a related study, residues of beta-lactam drugs were not found by LC/MS/MS in eggs from hens dosed orally with beta-lactam drugs. LC/MS/MS performance was evaluated on two generations of ion trap mass spectrometers, and key operational parameters were identified for each instrument. The ion trap acquisition methods could be set up for screening (a single product ion) or confirmation (multiple product ions). The lower limit of detection for screening purposes was 10-50 ppb (sulfonamides), 10-20 ppb (fluoroquinolones), and 10-50 ppb (tetracyclines), depending on the drug, instrument, and acquisition method. Development of this method demonstrates the feasibility of generic SPE, LC, and MS conditions for multiclass LC/MS residue screening.  相似文献   

13.
In 1990, under regulatory monitoring, a total of 19,962 samples of domestically produced food from all 50 states and Puerto Rico and imported food from 92 countries were analyzed by FDA for pesticide residues. Of these, 19,146 were surveillance samples, which are collected when there is no suspicion of a pesticide problem. No residues were found in 60% of domestic surveillance samples and in 64% of import surveillance samples. Of the 19,146 surveillance samples, 2.8% were violative. Under the incidence/level aspect of monitoring, 172 samples of fish/shell-fish, 330 samples of whole milk, and 3502 samples of processed foods including baby foods were analyzed for pesticide residues. Findings from these projects were consistent with regulatory monitoring data. The findings of the 1990 Total Diet Study are evidence that actual dietary intakes of pesticides are generally well below the standards established by FAO/WHO and by EPA. The 1990 results are similar to those obtained in earlier years and demonstrate the continuing safety of the food supply relative to pesticide residues.  相似文献   

14.
Prediction models for residue transfer into eggs are being developed. Recent results indicate that the developing egg yolk serves as an important storage depot for chemical residues. The current study was conducted to visualize incorporation and potential compartmentalization of drug residues in developing egg yolks. To this end, the drug magnevist was injected into hens to evaluate drug transfer into either early- or late-developing yolks. High-resolution magnetic resonance images (MRI) of drug residues in eggs were acquired using a 1.5 T Siemens Magnetom clinical scanner. A 10-cm circular surface coil was used for receiving the magnetic resonance signal. The eggs were positioned inside the coil cavity for an improved signal to noise ratio (SNR). Gradient-echo images were used to locate the centers of the eggs and to prescribe the position of the high-resolution image slab. The images were recorded using an inversion time (T1) weighted magnetization-prepared, rapid acquisition, gradient-recalled-echo (MPRAGE) pulse sequence. The sequence parameters used were as follows: repetition time (TR) equals 12 ms, echo time (TE) equals 5 ms, field of view (FOV) equals 200, TI = 10 ms, 1.25-mm slice thickness, and a matrix of 200 x 256. Following dosing, images of drug residues in eggs indicate that drugs can be incorporated and compartmentalized into ring structures within individual developing egg yolks. These results have significant human food safety implications because even after only a single dose, sequestered drug residues may be stored and later released to contaminate eggs for days to weeks after dosing.  相似文献   

15.
Extraction and analysis methods have been developed for the detection of the following four antibacterial agents and two natural estrogens in treated municipal wastewater sludge and commercial compost: sulfamethoxazole (SMX), sulfadimethoxine (SDM), tetracycline (TET), oxytetracycline (OXY), estrone (E1), and 17??-estradiol (E2). The antibiotics and estrogens were extracted from secondary sludge and mixed compost using ultrasonic solvent extraction. Citric acid (pH?4.7) and methanol were used as extraction buffer, followed by tandem-solid-phase extraction cleanup, strong anion exchange?+?hydrophilic?Clipophilic balance for antibiotics and CarboPrep/NAX for estrogens. For quantification, two different methods were employed, using HPLC?CMS/MS, with an electrospray ionization source for antibiotics and an atmospheric-pressure chemical ionization source for estrogens. Recoveries were 11?C31% for the sulfonamides (SMX and SDM) and tetracyclines (TET and OXY) and 30?C59% for the estrogens (E1 and E2) over the entire method. Limits of detection for the extraction method were in the nanogram per gram range for dry weight sludge and compost samples. Neither of the two sulfonamide antibiotics was detected in secondary sludge or mixed compost samples. Estrogens were found in compost in amounts of 160?±?65?ng/g (E1) and 21?±?3?ng/g (E2), but not in sludge. The tetracyclines, as well as what is believed to be the 4-epimer of OXY, were found in both sludge and compost in amounts of 1.57?±?0.67 and 2.95?±?0.42???g/g (TET), 0.56?±?0.12 and 6.51?±?0.52???g/g (OXY), and 7.60?±?1.68 and 1.35?±?0.24???g/g (4-epi-OXY), respectively. These results indicate that sorption-prone compounds are not removed during the wastewater treatment process and can persist through sludge digestion and that the composting process does not sufficiently eliminate these particular contaminants. Thus, biosolids (even composted) are an additional source of drug residues leaching into the environment, and it must be considered while using biosolids as fertilizer.  相似文献   

16.
A quadrupole time-of-flight (Q-TOF) liquid chromatography-mass spectrometry (LC-MS) method was developed to analyze veterinary drug residues in milk. Milk samples were extracted with acetonitrile. A molecular weight cutoff filter was the only cleanup step in the procedure. Initially, a set of target compounds (including representative sulfonamides, tetracyclines, β-lactams, and macrolides) was used for validation. Screening of residues was accomplished by collecting TOF (MS(1)) data and comparing the accurate mass and retention times of found compounds to a database containing information for veterinary drugs. The residues included in the study could be detected in samples fortified at the levels of concern with this procedure 97% of the time. Although the method was intended to be qualitative, an evaluation of the MS data indicated a linear response and acceptable recoveries for a majority of target compounds. In addition, MS/MS data were also generated for the [M + H](+) ions. Product ions for each compound were identified, and their mass accuracy was compared to theoretical values. Finally, incurred milk samples from cows dosed with veterinary drugs, including sulfamethazine, flunixin, cephapirin, or enrofloxacin, were analyzed with Q-TOF LC-MS. In addition to monitoring for the parent residues, several metabolites were detected in these samples by TOF. Proposed identification of these residues could be made by evaluating the MS and MS/MS data. For example, several plausible metabolites of enrofloxacin, some not previously observed in milk, are reported in this study.  相似文献   

17.
Turbidimetric methods for determining the potency of antibiotics are inherently more accurate and more precise than are comparable agar diffusion procedures, but assays conducted in liquid media are subject to degradation from less than ideal conditions to a much greater extent than are diffusion methods. The relationships between test organisms, antibiotics, and assay concentrations are discussed. A valid assay procedure must produce a linear response with an adequate slope (-0.4 to -1.2) by the test organism to increasing concentrations of drug; such linear response normally occurs over a limited range of concentrations. Criteria used to select photometers that offer the greatest advantages to analytical microbiologists are described, with guidelines for the most effective use of the chosen instrument.  相似文献   

18.
A recently developed confirmatory LC-MS method has been applied to the quantification of five major beta-lactam antibiotics in suspect raw bovine milk samples that gave a positive response with receptor-based (BetaStar) and rapid microbial inhibitory screen tests (Delvotest SP). In total, 18 presumptive positive raw milk samples were reanalyzed; 16 samples showed traces of antibiotic residues that could be identified and quantified by the LC-MS method, ranging from the limits of confirmation up to 38 microg/kg. Of the positive samples, only five (approximately 30%) were found to be violative of EU maximum residue limits. The most frequently detected antibiotic residues were cloxacillin and penicillin G, the former often in combination with amoxicillin or ampicillin. This study compares the results obtained by the three methods on identical samples and addresses how these relate to certain criteria such as sensitivity and selectivity. Furthermore, the limitations of the LC-MS method and the potential impact of the presence of frequently more than one residue in the same milk sample on the response of the rapid test methods are discussed.  相似文献   

19.
Tetracyclines are widely used in farm animals. This can cause drug residues in products of animal origin and, after excretion of these substances, in animal slurry and in soil fertilized with that slurry. In this paper, we present a method based on a microbiological assay coupled with HPLC for the detection of oxytetracycline, tetracycline, and chlortetracycline in eggs. After a simple liquid extraction of the samples and HPLC separation, fractions were collected on microtiter plates, and the tetracyclines were analyzed using the Staphylococcus aureus assay. This method was able to identify residues of tetracyclines in eggs at a level set by regulatory agencies (i.e., 200 microg/kg). In addition, it was shown that the described microbiological method can be used as a screening assay for the detection of tetracyclines and possible biologically active metabolites in animal slurry and soil samples. Employing the same extraction procedure, it was demonstrated that LC-MS-MS allowed the quantification of 20-400 microg/kg in eggs with recoveries ranging from 71 to 109% and RSDs of 3-15%.  相似文献   

20.
Tolerance setting process in the U.S. Environmental Protection Agency   总被引：1，自引：0，他引：1  
The U.S. Environmental Protection Agency (EPA) is responsible for setting tolerances for pesticide residues in food, under the authority of the Federal Food, Drug, and Cosmetic Act. The residue chemistry data required to set tolerances include metabolism in plants and animals, analytical methods, magnitude of the residue, and concentration in processed foods. A key aspect of tolerance-setting procedures is the identity of the residue in the matrix of concern; without knowledge of the chemical moieties that occur as residues, it is impossible to develop suitable methods or generate meaningful residue data. For new chemicals, EPA carries out a single-laboratory validation of the analytical method needed to generate residue data and to enforce tolerances. Tolerance enforcement methods need to be rapid and inexpensive and to use commercially available equipment and reagents. Methods are more complex for many newer pesticides, which are polar compounds that leave low levels of residue. EPA now requires that the registrants of older pesticides, for which methods are not acceptable by today's standards, must develop better methods.  相似文献   

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