Development of differential pulse voltammetric method for rapid quantification of total hydroxyl-sanshools in Sichuan Pepper

Hydroxyl-sanshools (HS) are primary components evoking specific pungent sensations of Sichuan Pepper (pericarp of Zanthoxylum bungeanum, PZB) which is widely used as a food condiment in Chinese cuisine. In present work, voltammetric characterisation of HS was investigated, and a protocol described an efficient electrochemical method (DPV) for detecting the content of total HS analyte quantitatively in PZB samples was first proposed. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed for the electrochemical reversibility of representative HS compounds, and the effect of the supporting electrolyte on the voltammetric signal of hydroxyl-α-sanshool (α-SOH) was investigated by DPV. Under the optimal operating conditions, DPV was used to quantify the concentration of α-SOH with satisfactory linearity (0.25–78.9 mg L−1), sensitivity (LOD = 0.03 mg L−1), repeatability (RSD = 2.1%). Furthermore, this DPV method via standard addition method was successfully used for the quantification of the total content of HS in PZB models in the linear range of 1.87 and 80.93 mg g−1. The established DPV method exhibited high measurement accuracy in actual PZB samples as compared with HPLC-MSn analysis and demonstrated satisfied recoveries (94.56–108.02%). Taken together, it was evidenced that this protocol was a hopeful alternative way to conveniently quantify total HS contents in PZB samples.