Integrated response surface methodology and UHPLC coupled with triple quadrupole time‐of‐flight MS quantitation to investigate the salt‐processing chemistry of traditional Chinese medicines: A case study on Achyranthes bidentata

Abstract

AbstractA sensitive ultra high performance liquid chromatography with tandem mass spectrometry approach for the quantification of eight bioactive constituents, including β‐ecdysterone, 25S‐inokosterone, achyranthoside D, ginsenoside Ro, chikusetsusaponin IV, achyranthoside C, chikusetsaponin IVa, and 13‐hydroxyoctadecadienoic acid, in raw and salt‐processed Achyranthes bidentata was developed and validated. Response surface methodology was employed for optimization of three parameters of ultrasound‐assisted extraction process, including the extraction time, methanol percentage, and solvent volume, to give optimum extraction conditions as follows: extraction time of 40.2 min, methanol percentage 67.2% v/v, and solvent volume of 48.4 mL. The established approach was interrogated in terms of linearity, sensitivity, precision, repeatability as well as recovery. Intra‐ and inter‐assay variability for all analytes ranged from 1.6 to 3.1% and from 2.0 to 3.2%, respectively. The standard addition method determined recovery rates for each analyte (99.2–103.6%). In addition, the developed approach was applied to 20 batches of collected raw samples of Achyranthes bidentata and their salt‐processed products. After salt‐processing, the contents of β‐ecdysterone, 25S‐inokosterone, achyranthoside D, chikusetsusaponin IV and achyranthoside C were elevated, while the content of ginsenoside Ro was decreased. The results showed that experimental design in combination with ultra high performance liquid chromatography with tandem mass spectrometry quantification provided insights into the chemistry alteration between raw Achyranthes bidentata and its salt‐processed product.