“…In the relevant consensus guidelines, the effective therapeutic concentration of VPA ranges from 50 to 100 μg/ml and the laboratory alert value is 120 μg/ml (Hiemke et al, 2018). The individual medication of VPA during treatment can improve the control rate of epilepsy and reduce adverse reactions (Gerstner, Bell, & Konig, 2008;Yukawa, 1996).To date, several methods for the quantification of VPA concentrations in biological fluids have been developed, such as immunoassay (Cooreman et al, 2008), liquid chromatography-mass spectrometry (LC-MS) (Gao et al, 2011;Zhao et al, 2016), high-performance liquid chromatography (HPLC) (Mao, Zhao, Sun, Lu, & Li, 2019) and gas chromatography (GC) (Shahdousti, Mohammadi, & Alizadeh, 2007). Among these methods, immunoassay is the most commonly used method in clinical laboratories, while lacking selectivity.…”