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

Table 4

Summary of validation results observed by the proposed method.

Parameter	PA	2-EPA	2-IsoPPA	VPA
LOD (𝜇g/mL)	0.5	0.5	0.5	0.5
LOQ (𝜇g/mL)	2.0	2.0	2.0	2.0
Accuracy (%)	99.12–99.80	98.27–101.1	100.01–101.9	98.56–101.35
Precision (RSD, %)
Method precision	0.61	1.21	0.90	1.07
Intermediate precision	0.91	0.33	0.56	1.34
Linearity
Range (𝜇g/mL)	50–400	50–400	50–400	50–400
Correlation coefficient	0.998	0.997	0.999	0.995
Slope	211.6	238.6	250.4	321.8
Intercept	−1217	12028	−8400	−7153
Theoretical plate	35426	21329	17200	31128
Asymmetry	1.06	1.23	1.02	1.31