Sample Preparation

A test portion of 50 mL per sample was filtered first through a glass filter with a porosity of 1.6 µm and then a second time through a filter with a porosity of 0.7 µm. The filtrates were brought to an oven at 100°C until complete evaporation. The salts obtained were removed from the oven and left under ambient laboratory conditions until cooling. Thus, 2.5 mL of the 0.1% acetic acid solution was used to elute the salts from each sample. The solutions obtained were well homogenized with a vortex before being brought to the HPLC for the analyses.

The rates of 3% and 97% for the mobile phase have been configured, respectively, for entry entries A and B. Thus, a test sample of 20µL of the solutions to be analyzed has been fixed. Also, a temperature of 40°C for the column and a wavelength of 254 nm for the UV detector were set. In total, 06 antibiotic standards (Table 1) were used to search for the same molecules in the 15 samples.

List of Antibiotic Standards Used