To examine the analytical performance of the present method, acetaminophen was used as the representative of the samples. Acetaminophen powder and corn starch were mixed (the ratio of acetaminophen powder in the mixture was 0%–100%) and then mixed powder was pressed into tablets using tableting machine. The re-pressed tablets containing acetaminophen were analyzed by the present method under the conditions of optimized desorption distance, time, and other parameters. The major fragment ion (m/z 110) of acetaminophen was selected as the quantitative ion and calibration curve was plotted using average value (n = 10) of net response signal of m/z 110 versus the concentration of acetaminophen powder in the mixture (Figure 6).Figure 6Calibration curve for acetaminophen. *The error bar in the curve is the standard deviation of net response signal