ABSTRACT
The determination of antimicrobials in aquaculture fish is important to ensure food safety. Therefore, simple and fast multiresidue methods are needed. A liquid chromatography tandem mass spectrometry method was developed and validated for the quantification of 14 antimicrobials (quinolones and tetracyclines) in fish. Antimicrobials were extracted with trichloroacetic acid and chromatographic separation was achieved with a C18 column and gradient elution (water and acetonitrile). The method was validated (Decision 2002/657/EC) and it was fit for the purpose. Linearities were established in the matrix and the coefficients of determination were ≥0.98. The method was applied to Nile tilapia and rainbow trout (nâ¯=â¯29) and 14% of them contained enrofloxacin at levels above the limit of quantification (12.53-19.01⯵g.kg-1) but below the maximum residue limit (100⯵g.kg-1). Even though prohibited in Brazil and other countries, this antimicrobial reached fish. Measures are needed to ascertain the source of this compound to warrant human safety.
Subject(s)
Fish Products/analysis , Food Contamination/analysis , Quinolones/analysis , Tandem Mass Spectrometry/methods , Tetracyclines/analysis , Animals , Anti-Bacterial Agents/analysis , Aquaculture/methods , Brazil , Chromatography, Liquid/methods , Cichlids , Enrofloxacin , Fluoroquinolones/analysis , Food Analysis/methods , Limit of Detection , Oncorhynchus mykiss , Reproducibility of ResultsABSTRACT
Antibiotics are widely used in veterinary medicine to treat and prevent diseases and their residues can remain in food of animal origin causing adverse effects to human health. Amphenicols (chloramphenicol, thiamphenicol, and florfenicol) may be found in foodstuffs, although the use of chloramphenicol has been prohibited in many countries due to its high toxicity. Since these antibiotics are usually present at trace levels in food, sensitive and selective techniques are required to detect them. This paper reviews analytical methods used since 2002 for the quantitative analysis of amphenicols in food. Sample preparation and separation/detection techniques are described and compared. The advantages and disadvantages of these procedures are discussed. Furthermore, the worldwide legislation and occurrence of these antibiotics in food matrices as well as future trends are also presented.
Subject(s)
Chloramphenicol/analysis , Chromatography/methods , Food , Thiamphenicol/analogs & derivatives , Thiamphenicol/analysis , Animals , Chloramphenicol/chemistry , Chloramphenicol/isolation & purification , Food Contamination/prevention & control , Humans , Molecular Structure , Reproducibility of Results , Thiamphenicol/chemistry , Thiamphenicol/isolation & purificationABSTRACT
The objective of this study was to develop and validate a fast, sensitive and simple liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the screening of six classes of antibiotics (aminoglycosides, beta-lactams, macrolides, quinolones, sulfonamides and tetracyclines) in fish. Samples were extracted with trichloroacetic acid. LC separation was achieved on a Zorbax Eclipse XDB C18 column and gradient elution using 0.1% heptafluorobutyric acid in water and acetonitrile as mobile phase. Analysis was carried out in multiple reaction monitoring mode via electrospray interface operated in the positive ionization mode, with sulfaphenazole as internal standard. The method was suitable for routine screening purposes of 40 antibiotics, according to EC Guidelines for the Validation of Screening Methods for Residues of Veterinary Medicines, taking into consideration threshold value, cut-off factor, detection capability, limit of detection, sensitivity and specificity. Real fish samples (n=193) from aquaculture were analyzed and 15% were positive for enrofloxacin (quinolone), one of them at a higher concentration than the level of interest (50µgkg-1), suggesting possible contamination or illegal use of that antibiotic.
Subject(s)
Anti-Bacterial Agents/analysis , Chromatography, Liquid/methods , Limit of Detection , Spectrometry, Mass, Electrospray Ionization/methods , Tandem Mass Spectrometry/methods , Tilapia , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Food Contamination/analysis , Time FactorsABSTRACT
The present study sought to develop lipid bases from blends between patawa oil and palm stearin. These blends were analyzed before and after the chemical interesterification process for their fatty acid and triacylglycerol composition, free fatty acid (FFA) content, peroxide index, thermal properties, melting point, consistency, and solid fat content (SFC). Blends with unsaturated fatty acid contents between 60 and 70% were obtained, with a good ratio between saturated and unsaturated fatty acids, which indicates a healthy content of fatty acids. Variations in the triacylglycerol contents and melting and crystallization thermograms evidenced the reaction. The blend with 50% stearin and 50% patawa oil showed the best results after the chemical interesterification reaction regarding the possible application in fatty products for its appropriate melting point, SFC similar to that of soft table margarines, plastic and spreadable consistency at refrigeration temperature, thus combining physical and nutritional properties desirable for the food industry.
Subject(s)
Esterification , Plant Oils/chemistry , Chemical Phenomena , Fatty Acids/analysis , Fatty Acids/chemistry , Fatty Acids, Nonesterified , Lipids/chemistry , Margarine , Palm Oil , Triglycerides/analysis , Triglycerides/chemistryABSTRACT
The b-lactoglobulin and alfa-lactalbumin whey proteins were separeted by liquid-liquid extraction using a 14 per cent polyethylene glycol 1550 - 18 per cent potassium phosphate phase system. The selection of the aqueous two-phase system was based on the phase ratio ant the protein partition coefficient. The proteins were quantified employing a Fast Protein Liquid Chromatography system
