[New solution of simultaneous equations in spectrophotometry for the determination of aspirin and acetaminophen in xiaoer tuishao pian].

The contents of aspirin and acetaminophen in xiaoer tuishao pian were determined by using the new solution of simultaneous equations without any preliminary separation. The average recoveries and variation coefficients of the analysis are 99.95% and 1.74% for aspirin and 100.1% and 0.93% for acetaminophen, respectively. The method was simple, rapid and accurate.