Exploratory Study for the development of new methodologies for antibiotics determination in water samples

Abstract

It is nowadays well established that antibiotics are constantly released to the environment as a consequence of their broad use in human and animal therapy. The presence of these substances in superficial, underground and residual waters, have being detected by several authors. Resistant bacterial strains and toxicity risks are the major concerning impact for the environment which demands a quality control of the waters. Thus, the development of new methodologies for environmental antibiotic determination is an important issue. The suitability of a Solid Phase extraction technique using a C-18 reversed phase packed material and several elution solvents were tested for detection of Tetracycline (TC), Chloramphenicol (CPA) and Streptomycin (STP) in standard water samples. The chromatographic separation was held in High Pressure Liquid Chromatography equipment with a diode array detector, using a C-18 reversed phase column (30cm x 3.9mm d.i., 5μm particle size). The specific absorption wavelenght for each antibiotic was montitorized: 357, 277, and 257nm for TC, CPA and STP. The elution solvent was determinant for the extraction step, as we achieve 77,1% of recovery for TC and 15,3% for CPA; no recovery was achieved for STP. Therefore, a method of analysis for the TC and CPA was established, however a separated method of analysis is suggested for the analysis of STP, due to its high polar behavior.

Keywords

• tetraciclina, cloranfenicol, estreptomicina, análise de águas, SPE, HPLC-DAD