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... the same incubation was performed with non-sterile samples of soil, the concentrations of chloramphenicol declined as a function of the incubation time as shown in Table 4. A graph of the same data (see Figure 1) suggests a biphasic curve for the degradation of chloramphenicol in soil. However, the second phase could be the result of the closeness to the LOQ of the observed concentrations. ...
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الخلاصة تم وصف طریقة طیفیة سهلة وحساسة لتقدیر الکلورامفینیکول بشکله النقی وفی مستحضراته الصیدلانیة. تعتمد الطریقة على التفاعل بین الکلورامفینیکول المختزل والکاشف اورثو- کلورانیل فی الوسط المائی القاعدی مکونا معقد الشحنة المنتقلة ذی لون ارجوانی یمتلک طیفا امتصاصیا له أقصى امتصاص عند 527 نانومیتر. أمکن تطبیق قانون بیر ضمن مدى التراکیز 2-65 مایکروغرام...
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... CAP is also prohibited in many other countries, including the USA, Canada, Australia, Japan, and China. No MRL has been established for this antibiotic (EC, 2009c; EEC, 1990; Wongtavatchail, McLean, Ramos, & Arnold, 2004). Despite this legal ban, CAP can be detected in several animalderived foods including aquaculture products and honey. ...
Background: Aquaculture is one of the worldwide strategic development fields, and its importance is evident in its significant worldwide growth in the last decades. This growth is associated with the implementation of intensive and semi-intensive production methods, with the use of antibiotics in order to prevent the emergence and spread of infectious diseases in fish. Fluoroquinolones, tetracyclines, and sulfonamides, among others, are widely used for this purpose. This practice constitutes a real public health concern, not only due to the presence of antimicrobial residues in edible tissues, which can cause allergic reactions in hypersensitive individuals, but also due to the emergence of bacterial resistance. Consequently, the European Union's Regulatory Agencies have established maximum residue limits and specific requirements regarding the performance of analytical methods. Scope and approach: This article reviews the most recent analytical methodologies concerning antimicrobial residues in fish, reported in the literature, given emphasis on sample procedures, extraction/purification methods, chromatographic conditions and validation techniques according to legislation. Key findings and conclusions: Liquid chromatography coupled to mass spectrometric detection is used as preferential tool in the analysis of antimicrobial residues in fish. The current analytical strategy is shifting towards multi-residue and multiclass methods, which save time, and surely represent the future trend in this field. The extraction process still represents the limiting factor of any multi-residual method, since it should provide acceptable recovery of all analytes with a broad range of physicochemical properties, and therefore this is probably the step that requires more in-depth research.
Button mushrooms are widely produced edible basidiomycetes. Commercially, they are cultivated on substrates containing fermented horse manure and chicken feces. Since pharmacologically active substances (PAS) might be introduced into the food chain via animal treatment, their residues may be present in manure used for mushroom growth. Previous studies in plants have demonstrated an uptake of PAS from the agricultural environment. The present study was performed to investigate the presence of PAS in button mushrooms. For analysis, a multi-analyte method for the detection of 21 selected PAS using liquid chromatography tandem-mass spectrometry was developed, successfully validated and applied to commercially available button mushrooms. Traces of chloramphenicol were detected in two of 20 samples. Additionally, in a mushroom cultivation experiment an uptake of ciprofloxacin, chloramphenicol and praziquantel was conducted. Throughout the whole experiment, praziquantel was present in quantifiable amounts in mushrooms and in high quantities in soil.
A reliable liquid chromatography-tandem mass spectrometry method was developed to determine total florfenicol residues in bovine tissues and eel. Florfenicol and its metabolites (florfenicol amine, monochloroflorfenicol, florfenicol oxamic acid, and florfenicol alcohol) were analyzed as the marker residue, florfenicol amine, as defined by several regulatory agencies. After hydrolysis with hydrochloric acid, samples were defatted and subjected to solid-supported liquid extraction and Oasis MCX-cartridge cleanup before analysis. The method was validated for florfenicol and its metabolites at two levels in eel and bovine muscle, fat, and liver. Excellent recoveries were obtained (93–104%), with relative standard deviations of <6% for all compounds. Negligible matrix effects and minimal analyte loss during sample preparation enabled accurate quantification by external calibration using solvent standards. No interfering peaks were observed around the retention time of florfenicol amine, indicating the high selectivity of the method. Retention times in the spiked samples corresponding to that of the calibration standard in solvent did not exceed ±0.1 min. Ion ratios from the spiked sample were within ±10% (relative) of the calibration standards. Calibration curves were linear in the range of 0.5 to 100 ng/mL, with coefficients of determination higher than 0.998. The limits of quantification and limits of detection of the proposed method were estimated to be 0.01 mg/kg and 0.0005 mg/kg, respectively, in all food samples. Thus, the developed method is considered reliable and suitable for regulatory use.
IntroductionCarbadox and OlaquindoxCeftiofur and DesfuroylceftiofurChloramphenicolNitrofuransNitroimidazoles and Their MetabolitesSulfonamides and Their N4-Acetyl MetabolitesTetracyclines and Their 4-EpimersMiscellaneousSummaryAbbreviationsReferences
Occurrence, removal, consumption and environmental risks of sixteen antibiotics were investigated in several sewage treatment plants (STPs) featuring different treatment levels in Hong Kong, China. Cefalexin, ofloxacin and erythromycin-H(2)O were predominant with concentrations of 1020-5640, 142-7900 and 243-4740 ng/L in influent, respectively; their mass loads were comparable to levels reported in urban regions in China and were at the high end of the range reported for western countries. The target antibiotics behaved differently depending on the treatment level employed at the STPs and relatively higher removal efficiencies (>70%) were observed for cefalexin, cefotaxime, amoxicillin, sulfamethoxazole and chloramphenicol during secondary treatment. ß-lactams were especially susceptible to removal via the activated sludge process while macrolides were recalcitrant (<20%) in the dissolved phase. Two fluoroquinolones, ofloxacin (4%) and norfloxacin (52%), differed greatly in their removal efficiencies, probably because of disparities in their pK(a) values which resulted in different sorption behaviour in sludge. Overall antibiotic consumption in Hong Kong was back-calculated based on influent mass flows and compared with available prescription and usage data. This model was verified by a good approximation of 82% and 141% to the predicted consumption of total ofloxacin, but a less accurate estimate was obtained for erythromycin usage. Risk assessment indicated that algae are susceptible to the environmental concentrations of amoxicillin as well as the mixture of the nine detected antibiotics in receiving surface waters.
