STUDY ON THE SPECTROPHOTOMETRIC DETERMINATION OF AMINOGLYCOSIDE ANTIBIOTICS WITH TRYPAN RED

In a medium of pH 2.8~7.0, trypan red (TR) reacts with aminoglycoside antibiotics, such as tobramycin sulfate (TOB), gentamycin sulfate (GEN) and neomycin sulfate (NEO), to form red ion association complexes. The maximum absorption wavelengths for these systems were at 392 nm (NEO、GEN) and 570 nm (TOB), respectively. The linear ranges were from 0~14.0 mg ·L~(-1) to 0 ~16.0 mg·L~(-1) for different systems with molar absorptivities (e) between 7.65×10~3 and 1.40×10~4L·mol~(-1)·cm~(-1). The maximum fading wavelengths were located at 502 nm (NEO) and 498 nm (GEN、TOB) respectively, and the linear ranges were between 0~13.0 mg·L~(-1) and 0~16.0 mg ·L~(-1) with molar absorptivities (e) from 4.02×10~3 to 9.32×10~3L·mol~(-1)·cm~(-1). When the dual-wavelength absorption spectrometry was used to determine the aminoglycoside antibiotics, their molar absorptivities e were between 1.46×10~4 and 2.67×10~4L·mol~(-1)·cm~(-1). The optimum reaction conditions and main analytical properties were studied. The method has been applied to the determination of aminoglycoside antibiotics with satisfactory results.