Table 1.

Methods for the preparation of stock solutions and working standard solutions of antibiotics.

Antimicrobial agents	Solvents	Diluents
β –lactams	Phosphate buffer, pH 6.0, 0.1 mol/L	Phosphate buffer, pH 6.0, 0.1 mol/L
Aminoglycosides	Tris, pH 8.0, 0.01 mol/L	Tris, pH 8.0, 0.01 mol/L
Tetracyclines	HCl, 0.1 mol/L	Phosphate buffer, pH 6.0, 0.1 mol/L
Macrolides	Phosphate buffer, pH 8.0, 0.01 mol/L	Phosphate buffer, pH 8.0, 0.01 mol/L
Sulfonamides	NaOH, 0.1 mol/L	Sterilized distilled water
Lincosamides	Phosphate buffer, pH 8.0, 0.01 mol/L	Phosphate buffer, pH 8.0, 0.01 mol/L
Quinolones	NaOH, 0.1 mol/L	Phosphate buffer, pH 8.0, 0.1 mol/L
TMP	Glacial acetic acid	Sterilized distilled water
CAP	Methanol	Sterilized distilled water