复方磺胺甲基噁唑是一种广谱抗菌类药物.本文探讨了微分紫外吸收光谱法测定该药片剂中磺胺甲基噁唑(SMZ)和甲氧苄氨嘧啶(TMP)含量的最佳条件.在0.01mol/L NaOH溶液中,用二阶微分(△λ=2nm)光谱,在波长为243.5nm外测定TMP的含量:用三阶微分(△=4nm)光谱,在波长为244.8nm外测定SMZ的含量,各组分互不干扰,测定回收率为99.8～101.8%.本方法不需要烦杂的分离操作,简便快速,精确度高. Compound sulfamethoxazole is a broad-spectrum antimicrobial drug.In this paper, the best determination of sulfamethoxazole (SMZ) and trimethoprim (TMP) in this tablet by differential ultraviolet absorption spectrometry Conditions TMP content was determined by a second-order differential (Δλ = 2 nm) spectrum at a wavelength of 243.5 nm in a 0.01 mol / L NaOH solution: A third-order differential (Δ = 4 nm) spectrum was used at a wavelength of 244.8 nm The content of SMZ was measured outside without disturbing each other, and the recovery rate was 99.8 ~ 101.8% .This method does not require complicated separation operation, which is simple, rapid and accurate.