Tetracycline Lab Report

Keywords: HPTLC, Tetracyclines, residues and broiler meat, validation Introduction
Tetracycline antibiotics (TCs) which are represented by oxytetracycline (OTC) and tetracycline (TC), are active against gram positive and negative bacteria antimicrobials and are commonly used in livestock and poultry for prevention and treatment of various diseases [1]. Chemical names for these antibiotics are 4-(Dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro3,5,6,10,12,12a-hexahydroxy-6-methyl-1,11-dioxo-2-naphthacenecarboxamide, and (4S,6S,12aS)-4-(dimethylamino)-1,4,4a,5.5a,6,11,12a-octahydro-3,6,10,12,12a-pentahydroxy-6-methyl-1,11-dioxonaphthacene-2-carboxamide for TC and OTC, respectively. The chemical structures of these drugs are as shown in Figure

[22]. Before solution application, the HPTLC plates were sprayed with 10% (w/v) disodium ethylene diaminetetraacetic acid (Na2EDTA) solution in which the pH had been adjusted to 4 using glacial acetic acid. This Na2EDTA solution helps to avoid binding of the tetracyclines with trace metals in the adsorbents used [23]. Since OTC and TC have similar chemical and physicochemical properties they form chelate complexes with metal ions and bind with proteins and silanol groups in the stationary phase. These undesirable properties have been controlled by the use of EDTA for plate treatment [23]. After the spraying, plates were left for at least 1hour at room temperature and then in an oven at 110oc for 1 hour in order to activate themit before use. Then, a 2µl of solutions of separate individual and mixture of reference standards (OTC and TC) in methanol were applied on HPTLC

In doing this, the different wavelength ranging from 200 to 400nm of individual spectra of oxytetracycline and tetracycline were obtained and superimposed to determine wavelength with sufficient absorption of the compounds. The slit dimensions of the Scanner III were set at 6mm x 0.45mm, the data resolution at 100µm/step and the scanning speed at 20mm/s.

Mobile phase