Valuation of techniques in tube SPME/LC in the determination of sulfonamides at egg samples

• Grant number: 10/00801-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2010
• End date: November 30, 2011
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Maria Eugênia Queiroz Nassur
• Grantee: Valeria Cristina Jardim
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Veterinary medicinal products have been used on a large scale due to modern farming practices. The use of veterinary drugs in birds may affect population health and international trade of food, due to the presence of drug residues or metabolites in foods such as milk and eggs. The main factors that determine the occurrence of residues of veterinary products in eggs are: not following the time period (time between drug administration and collection of the egg), route of administration, contamination of feed or water, the physicochemical properties, and biotransformation of the drug, and the physical condition of the hen bird. The amount of residue present in the food considered safe depends on toxicológical studies. The sulfonamides are synthetic drugs used extensively to treat bacterial infections caused by gram-positive and gram-negative microorganisms. These compounds are derived from p-aminobenzenosulfonamida, characterized by an aryl group containing an amino group and a sulfonamide group in a position para. The presence of sulfonamide residues in food should be taken into account, since these compounds may increase the risk of resistance to antibiotics. Residues of sulphonamides can also be found in biological fluids such as urine and plasma. To control the presence of such residues in products of animal origin, it is necessary to develop analytical sensitive methods and accurate. A new SPME-LC system, called "in-tube" SPME, was recently developed for the microextraction and preconcentration of some volatile organic compounds and/or thermally unstable. Use capillary fused silica (SPME device), with the inner surface coated with the stationary phase, which has been engaged in line with the LC system. It allows automation of the extraction process, resulting in greater precision and less analysis time, compared to techniques off-line. As the samples are injected into the system, practically in their physiological state, decreases the exposure of analysts to the samples, while minimizing loss of solute during the extraction process. Phases of extraction ion exchange consisting of ionic groups covalently linked to insoluble matrices, inorganic, such as silica. Stages of extraction with the ionic groups NR3 + and NH3 + assets are classified as anion exchange strong and weak, respectively. The extraction mechanism is based on electrostatic attraction and competition between the counter-ions and solvent molecules ionic solute by charged ions chemically bound to the opposite phase extraction. This paper proposes the determination of sulfonamides: sulfamethazine, sulfamethoxazole, sulfametizol, sulfamerazine, sulfadimethoxine, and sulfaquinoxaline in samples of eggs using the system in-tube SPME / LC-UV-phase ion exchange. (AU)