Synchronous microextraction of active and toxic compounds from medicinal plant using nano-SiO2 assisted miniaturized matrix solid-phase dispersion

Abstract

The technique of nano-SiO2-assisted miniaturized matrix solid-phase dispersion (MMSPD) was successfully developed and applied for the first time in synchronous microextraction, concentration, and separation of active and toxic ingredients from Corydalis Rhizoma. Nano-SiO2 was served as a sorbent in the MMSPD, providing a larger specific surface area and better hydrophilicity, resulting in more efficient extraction of the target compounds. The MMSPD mixture was obtained by grinding 10 mg Corydalis Rhizoma, the standard solution of toxic compounds, and nano-SiO2 (40 mg) for 60 s. The sample mixture was then eluted with MeOH + 4 % (v/v) formic acid (pH = 4.8) elution solution. The analysis of sample extracts were performed by high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The response surface methodology predicted that the optimum amount of sorbent, the grinding time, and the pH of the elution solvent were 40.11 mg, 60.34 s, and 4.74, respectively. The technique was validated by the methodology and was able to obtain good linearity (R2 > 0.992) as well as a low detection limit (0.05 to 3.00 ng mL−1). Meanwhile, the precision of the method was verified with interday precisions (RSD%, n = 6) in the range of 1.7–4.4 % for peak area. The result of the sample analysis indicated that trace amounts of propazine, trietazine, and simazine were detected in the Corydalis Rhizoma sample, and the content of tetrahydropalmatine is 0.82 μg mg−1. The extraction recoveries ranged from 80.3 % to 109.6 %. This effective microextraction method is suitable for synchronous extraction of isoquinoline alkaloids and triazine herbicides from Corydalis Rhizoma samples.