Concentration (ng/mL) 0.04 0.1 0.2 0.4 0.8 1.6   peak area standard solution 5178 13941 26410 54303 107938 214381 (u V.S) tested               control solution 5571 14405 25876 52716 106399 219319

Table 5: Stability of ameziniummetilsulfate (AM) standard solution