Abstract:

In sodium hydroxide solution, oxacillin(OXA) can be bound to some basic triphenylmethane dyes such as methyl violet(MV), ethyl violet(EV) or malachite green(MG) to form a new product, resulting in a great enhancement of resonance Rayleigh scattering(RRS) and the appearance of a new RRS spectrum. The maximum RRS peak locates at 333 nm for MV system, 342 nm for EV system and 343 nm for MG system, respectively. The RRS intensity was directly proportional to the OXA concentration in the range of 0.080～0.60 mg/L for MV system, 0.040～0.40 mg/L for EV and MG systems, respectively. The lowest detection limits(3σ) of OXA were 0.064 mg/L for MV system, 0.024 mg/L for EV system, and 0.013 mg/L for MG system, respectively. Among these three systems, the MG system has the highest sensitivity, and the effects of the coexisting substances were investigated for this system. The results indicate that this assay has a good selectivity. The system is applied to the determination of oxacillin in human urine liquid, serum and commercial pharmaceuticals with satisfactory results.

Key words: triphenylmethane, oxacillin, resonance scattering