Determination of Suffamethoxazole and Trimethoprim in Compound Sulfamethoxazole Tablets by Dual Wavelength TLC Scanning

Objective:To establish a method using dual wavelength TLC-scanning for the determination of sulfame- thoxazole(SMZ) and trimethoprim(TMP) in compound sulfamethoxazole tablets.Method:Developer of selection was chloroform-methanol(9:1),wavelength of the SMZ was λ_S=271 nm,λ_R=335 nm;wavelength of the TMP was λ_S= 275 nm,λ_R=325 nm.The determination were carried out with the reflection zigzag scanning,SX=7,slit=0.4 mm× 0.4mm,sensitivity:X1,scan speed:12 mm·min~(-1).Result:The linear ranges of SMZ and TMP were 2.00-10.00 μg(r=0.9995 ) and 0.40-2.00μg (r=0.9996 ) respectively,the average recovery rates (n=6) of SMZ and TMP were 99.2% (RSD=0.46%)and 99.6%(RSD=0.80%) respectively.Conclution:The method was proved to be simple, rapid,accurate and reproducible.