An Isocratic Method for Quantification of Valproic Acid and Its Related Impurities Using Ion Pair Reagent by Ultraperformance Liquid Chromatography

Table 3

Data for robustness.

% CV
Condition	PA	2-EPA	2-IsoPPA	VPA
Column change	0.1	0.1	0.2	0.1
MP ratio change (56 : 44)	0.9	0.05	0.1	0.4
MP ratio change (54 : 66)	0.5	0.8	0.3	0.1
Flow rate change (1.10 mL/min)	1.6	1.4	1.1	0.6
Flow rate change (1.3 mL/min)	1.4	0.3	0.2	0.1