共查询到20条相似文献,搜索用时 15 毫秒
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An indirect conductimetric screening method using three test bacterium-medium combinations was developed for rapid detection of antibiotic residues in bovine carcasses. The detection time (DT), i.e. the point when the growth of the test bacterium was detected, was determined by observing the rate of change in the conductance plotted against time. This detection time averaged half of the reference time recorded by the instrument software. Total change in conductance (TC) was used as a further measure of growth. Threshold values for DT and TC were determined with inhibitor-free kidney samples. The presence of a residue was indicated if the DT exceeded the respective threshold value and was confirmed if the TC remained below the TC threshold value. The limits of detection (LODs) determined with fortified samples were at about or below the MRLs for cephalexin, chlortetracycline, ciprofloxacin, dihydrostreptomycin, enrofloxacin, oxytetracycline and penicillin G. The LODs for penicillin G, oxytetracycline and the sum of enrofloxacin and ciprofloxacin were also estimated with incurred samples; these samples were also analysed using liquid chromatography. The LODs determined with fortified and incurred samples were in close agreement. Given its rapid detection, good sensitivity to a wide range of antibiotics and ease of performance, the indirect conductimetric method developed here would seem to offer an appealing alternative to agar diffusion tests. 相似文献
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Antía Fdez-Sanromán Marta Pazos Emilio Rosales María Ángeles Sanromán 《Current Opinion in Electrochemistry》2021
Overall, investigations about the utilization of electrokinetic technology alone or in combination with other processes have attracted particular attention in recent years for remediation of soils contaminated with heavy metals and organic compounds. This fact is due to its peculiar benefits together with its capability of operating in a fine and low-permeability matrix. This review aimed to ascertain the most recent developments on the commonly proposed integrated technologies (electrokinetic soil washing, electrokinetics coupled with permeable reactive barriers, electrokinetic-advanced oxidation processes, and bioelectrokinetic remediation), by evaluating the gaps, challenges, and trends of these systems in the last years. Special attention is paid to the current approaches for overcoming the main bottlenecks of electrokinetics concerning scale-up and reduction of electric energy consumption by integration of renewable energies. 相似文献
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Sample preparation techniques for the determination of trace residues and contaminants in foods 总被引:1,自引:0,他引:1
The determination of trace residues and contaminants in complex matrices, such as food, often requires extensive sample extraction and preparation prior to instrumental analysis. Sample preparation is often the bottleneck in analysis and there is a need to minimise the number of steps to reduce both time and sources of error. There is also a move towards more environmentally friendly techniques, which use less solvent and smaller sample sizes. Smaller sample size becomes important when dealing with real life problems, such as consumer complaints and alleged chemical contamination. Optimal sample preparation can reduce analysis time, sources of error, enhance sensitivity and enable unequivocal identification, confirmation and quantification. This review considers all aspects of sample preparation, covering general extraction techniques, such as Soxhlet and pressurised liquid extraction, microextraction techniques such as liquid phase microextraction (LPME) and more selective techniques, such as solid phase extraction (SPE), solid phase microextraction (SPME) and stir bar sorptive extraction (SBSE). The applicability of each technique in food analysis, particularly for the determination of trace organic contaminants in foods is discussed. 相似文献
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Honey produced by honeybees is a valuable food product. The presence of xenobiotics in honey may harm its quality and constitute a danger to human health. Antibiotics are commonly applied by beekeepers to eliminate disease among honeybees. Moreover, ubiquitous administration of antibiotics may cause bacteria to become resistant to many drugs and spread antibiotic-resistant strains of bacteria. Appropriate sample preparation and determination of antibiotics at very low concentrations in foodstuffs are real analytical challenges. This article reviews analytical methods used for determination of residues of different sorts of antibiotic in honey and other honeybee products. 相似文献
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Mass spectrometry for identifying pharmaceutical biotransformation products in the environment 总被引:1,自引:0,他引:1
T. Kosjek E. Heath M. Petrovi D. Barcel 《Trends in analytical chemistry : TRAC》2007,26(11):1076-1085
Many classes of pharmaceuticals have been detected in wastewaters and surface waters around Europe, but little is known about their occurrence, fate and potential harmful effects on the environment, and that makes them an important group among those compounds considered to be new emerging contaminants. To understand the cycling of pharmaceuticals and their metabolites, it is essential to possess qualitative and quantitative information on their presence in the environment. This review covers the current status and future prospects of advanced hyphenated mass spectrometric (MS) techniques (gas chromatography-MS (GC-MS) and liquid chromatography-MS (LC-MS)) in elucidating the structures of trace contaminants, namely pharmaceutical biodegradation products in complex environmental matrices. The article is oriented towards technique and method and discusses capabilities, potential and limitations of different GC and LC mass analyzers (quadrupole, ion trap, time-of-flight and hybrid techniques) in dealing with analytical challenges of complex matrices and trace contaminants. We also give practical examples of their applications. The main scope of this article is to support and to facilitate the on-going research on pharmaceutical biodegradation products in environmental samples. 相似文献
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Mariël G. Pikkemaat 《Analytical and bioanalytical chemistry》2009,395(4):893-905
Monitoring of food products from animal origin for the presence of antimicrobial residues is preferably done using microbial
screening methods because of their high cost-effectiveness. Traditionally applied methods fail to detect the maximum residue
limits which were established when EU Council Regulation 2377/90 came into effect. Consequently, during the last decade this
has led to the development of improved microbial screening methods. This review provides an overview of the efforts expended
to bring antibiotic screening methods into compliance with EU legislation. It can be concluded that the current situation
is still far from satisfactory. 相似文献
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Food contamination continues to be a serious problem around the world. Surveillance of chemical contaminants in foods is important not only for public health but also because of the negative economic impact of contamination. From the analytical perspective, analysis of contaminants in food is an extremely challenging area. There is a wide variety of questions, ranging from the quantification of extremely low levels of individual components to the detailed assessment and evaluation of the analytical technique possibilities. This review considers the applications of CE coupled to MS detection (CE-MS) for the analysis of organic contaminants in food. Analytical information on sample concentration techniques, as well as on the CE separation conditions and recoveries obtained from water and food are provided. Different sections include several fields of application, such as pesticides, drug residues, or toxic formed during food processing in different matrices. A number of tables report a comprehensive listing of CE-MS applications. As a result, this work presents an update overview on the principal application of CE-MS together with a discussion of their main advantages and drawbacks, and an outline of future trends on analysis of organic contaminants. 相似文献
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Michael Petz 《Monatshefte für Chemie / Chemical Monthly》2009,140(8):953-964
Abstract Optical biosensors based on surface plasmon resonance are increasingly used to detect and (semi)quantify residues and contaminants
in food. This review provides an overview of the methods published in this field since the year 2003. Such biosensors have
mostly been applied to veterinary drug residues, like aminoglycosides, beta-agonists, cephalexin, chloramphenicol, fluoroquinolones,
levamisole, nicarbazin, nitroimidazoles, penicillins, ractopamine, sulfonamides, tetracyclines, and tylosin in milk, egg,
honey, prawn, muscle, liver and kidney. Only a few methods have been published on pesticide residues, mycotoxins, phycotoxins,
polychlorinated biphenyls and surfactants. These procedures are described with regard to biological recognition element, type
of sensor chip, immobilisation procedure, sample extraction and clean-up, crossreactivity, nonspecific binding, matrix interference,
chip regeneration, assay formats, calibration, validation and instrumentation.
Graphical Abstract
相似文献
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Recent applications of surface plasmon resonance biosensors for analyzing residues and contaminants in food 总被引:1,自引:0,他引:1
Michael Petz 《Monatshefte für Chemie / Chemical Monthly》2009,395(4):953-964
Abstract
Optical biosensors based on surface plasmon resonance are increasingly used to detect and (semi)quantify residues and contaminants in food. This review provides an overview of the methods published in this field since the year 2003. Such biosensors have mostly been applied to veterinary drug residues, like aminoglycosides, beta-agonists, cephalexin, chloramphenicol, fluoroquinolones, levamisole, nicarbazin, nitroimidazoles, penicillins, ractopamine, sulfonamides, tetracyclines, and tylosin in milk, egg, honey, prawn, muscle, liver and kidney. Only a few methods have been published on pesticide residues, mycotoxins, phycotoxins, polychlorinated biphenyls and surfactants. These procedures are described with regard to biological recognition element, type of sensor chip, immobilisation procedure, sample extraction and clean-up, crossreactivity, nonspecific binding, matrix interference, chip regeneration, assay formats, calibration, validation and instrumentation. 相似文献13.
A multi-screening approach for monitoring potential chemical contaminants in honey by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) has been developed. A total of 42 veterinary drugs (5 tetracyclines, 7 macrolides, 3 aminoglycosides, 8 beta-lactams, 2 amphenicols and 17 sulfonamides) were surveyed with the ultimate goal of unambiguously confirmed and quantified these analytes at a concentration level of 20 microg/kg. A basic sample preparation including four subsequent liquid/liquid extraction steps was necessary to adequately extract the compounds of interest from the honey. The four extracts were injected into the LC-ESI-MS/MS using a stacking injection procedure. Validation of the entire procedure was carried out according to the European Union directive 2002/657/EC at three concentration levels, i.e., 10, 20 and 30 microg/kg. Good performance data were obtained for 37 analytes, out of the 42 studied. Limit of compliance and detection limit were calculated based on an internal limit set at 20 microg/kg for all the compounds and ranged between 24-30 and 27-80 microg/kg, respectively. A limited survey on honeys of different geographical origins has demonstrated that positive honey samples were often contaminated by more than one class of drugs, thus highlighting the usefulness of such multi-screening approach to ensure and warrants the quality of honey. 相似文献
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固相萃取技术在食品痕量残留和污染分析中的应用 总被引:3,自引:0,他引:3
食品痕量残留和污染分析中,样品的前处理极为重要,也是其难点所在。由于食品和农产品样品的多样性和复杂性,目前还没有一种前处理技术能够适合所有情况下的所有样品。本文对近年来发展起来的新型固相萃取技术如固相微萃取、搅拌棒吸附萃取、基质固相分散萃取、分子印迹固相萃取、免疫亲和固相萃取、整体柱固相萃取、碳纳米管固相萃取等在食品痕量残留和污染分析中的应用进行了综述,对未来的发展前景作了展望。 相似文献
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The Calf Antibiotic and Sulfonamide Test (CAST), a microbial inhibition screening test, was developed for detecting antibiotics and sulfonamides in bob veal calf carcasses. The test uses Bacillus megaterium ATCC 9885 as the indicator organism and Mueller Hinton agar as the growth medium. Compared to Swab Test on Premises (STOP), developed in 1970, this screening test has higher sensitivity and the ability to detect a wider range of veterinary antimicrobial residual drugs, particularly sulfonamides, at lower concentrations. Carcasses that are tested with CAST and suspected of containing chemical residue above tolerance level are retained for confirmation. Disposition of these carcasses are determined upon laboratory result. Routine testing of bob veal calves with CAST allowed the Food Safety and Inspection Service to release most calf carcasses within 24 h post-slaughter, thus conserving shipping and handling resources. However, changes in the regulation in 1990 dictate that disposition of carcasses found to contain violative levels of sulfonamide residues should be based on laboratory findings. The analysis of the data for the years 1990-1994 and 1998 indicate that the use of CAST over the years was significant, and had a direct impact on reduction of residue violations in veal carcasses. With the use of CAST, potentially harmful antimicrobial chemicals entering the human food chain through veal meat have been minimized. 相似文献
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Comparison of the effectiveness of recent extraction procedures for antibiotic residues in bovine muscle tissues 总被引:3,自引:0,他引:3
Acetonitrile extraction followed by primary-secondary amine dispersive SPE cleanup QuEChERS (quick, easy, cheap, effective, rugged, and safe), was compared to pressurized liquid extraction (PLE) using water at 70 degrees C for 10 min at 1500 psi for the determination of 16 veterinary drugs in bovine muscle tissues by LC/MS/MS. PLE was significantly more effective for the extraction of veterinary drugs (ranging from 69 to 103% with RSD < or = 18%) than QuEChERS (ranging from 19 to 89% with RSD < or = 19%). Linearity of the calibration curves was obtained over the range considered from 10 microg/kg or LOQ to 1000, microg/kg) with r2 > or = 0.99 for all the analytes by both methods. Although an internal standard was used, matrix effects were corrected using matrix- matched standards. LODs were from 5 to 30 microg/kg for PLE and from 10 to 100 microg/kg for QuEChERS. To establish and assess the most efficient conditions for each extraction method, statistical parametric and nonparametric tests were used. PLE with water almost eliminates the use or generation of hazardous wastes. The two methods were applied successfully in a routine analysis during surveys in 2008. 相似文献
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Tamás Csay Gergely Rácz Erzsébet Takács László Wojnárovits 《Radiation Physics and Chemistry》2012,81(9):1489-1494
The γ-radiolytic degradation of chloramphenicol (CPL) was investigated in 0.1–1 mmol dm?3 aqueous solutions at various radiation conditions. The destruction of CPL was monitored by UV–vis spectrophotometric method through the decrease in the intensity of the absorbance band at 276 nm. LC-MS/MS was used to identify the degradation products. Results indicate that ?OH can add onto the CPL aromatic ring or can abstract H-atom from the side chain. The reductive dechlorination of CPL was also studied based on the reaction of eaq? with CPL. In 0.1 mmol dm?3 solution above 2.5 kGy dose complete CPL degradation was achieved. In the presence of dissolved oxygen at relatively low dose, various oxidation products were observed. In the presence of tertiary butanol radical scavenger tertiary butanol group containing products were also detected. The toxicity increased as a function of dose to 1.0 kGy. At doses higher than 1.0 kGy the toxicity decreased continuously due to further degradation. It was also demonstrated that the O2??/HO2? pair has low reactivity in CPL solution. 相似文献
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Concern is growing over the contamination of the environment with pharmaceutical residues, among which non-steroidal anti-inflammatory
drugs (NSAIDs) are one of the most abundant groups. Their widespread appearance in the aquatic environment is because of their
high consumption and their incomplete removal during wastewater treatment. Because effective operation of wastewater-treatment
plants is important for minimising the release of xenobiotic compounds, for example pharmaceutical products, into the aquatic
environment, our study focuses on removal of commonly used NSAIDs (ibuprofen, naproxen, ketoprofen, diclofenac) and clofibric
acid in a specially designed small-scale pilot wastewater treatment plant (PWWTP). This study shows that, except for diclofenac,
steady-rate removal of NSAIDs over a two-year monitoring period has been achieved. Elimination of the compounds in the PWWTP
was ≥87% for ibuprofen, naproxen and ketoprofen but only 49–59% for diclofenac. We also studied clofibric acid. Results after
one month of operation revealed 30% elimination with no sign of adaptation by the biomass. Also described are degradation
products of diclofenac, which we were able to identify because of the similarity of their mass spectra with those in the NIST
library and by comparing the retention times of different compounds. Although the structures of these compounds were confirmed
with a high probability (99%), we still need to compare the fragmentation of authentic compounds with degradation products
formed under our experimental conditions. Degradation products of ibuprofen, naproxen, ketoprofen, and clofibric acid were
found but these must be identified by use of high-resolution mass spectrometry and analysis of authentic compounds. 相似文献
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Liquid chromatography-tandem mass spectrometry for the analysis of pharmaceutical residues in environmental samples: a review 总被引:3,自引:0,他引:3
Pharmaceutical residues are environmental contaminants of recent concern and the requirements for analytical methods are mainly dictated by low concentrations found in aqueous and solid environmental samples. In the current article, a review of the liquid chromatography-tandem mass spectrometry (LC-MS/MS) based methods published so far for the determination of pharmaceuticals in the environment is presented. Pharmaceuticals included in this review are antibiotics, non-steroidal anti-inflammatory drugs, beta-blockers, lipid regulating agents and psychiatric drugs. Advanced aspects of current LC-MS/MS methodology, including sample preparation and matrix effects, are discussed. 相似文献
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K. Fischer P. Riemschneider D. Bieniek A. Kettrup 《Fresenius' Journal of Analytical Chemistry》1994,350(7-9):520-527
Several residues of the brewing industry and slaughtering offals were investigated in order to evaluate their potential as raw materials for the hydrolytic preparation of amino acid containing solutions, applicable as extractants in amelioration processes for metal polluted soils. The residues were hydrolysed with 6 mol/L hydrochloric acid and the hydrolysates were analysed for their total nitrogen, TOC, amino acid and heavy metal contents. Then, the leaching capacities of the hydrolysates were examined in a series of batch tests with a contaminated soil.High amino acid yields in relation to the weight of the air-dried raw materials were achieved with blood meal (72.5%) and poultry feather meal (56.6%). The portion of the detected amino acids of the total organic carbon content of the hydrolysates ranged from 38.9% (brewer's spent grain) to 93.6% (blood meal). In extraction tests with hydrolysates adjusted to a total amino acid concentration of 60 mmol/L and to a pH value of 7.0, maximum extraction yields of 50.3% for copper (soil content 279 mg kg–1) and 38.7% for nickel (soil content 54 mg kg–1) were reached. An increase of the hydrolysate concentration and of the pH of an amino acid mixture resulted in higher solubilisation of the metals.Dedicated to Prof. Dr. Dieter Klockow on the occasion of his 60th birthday 相似文献