Ultrasonic/microwave–assisted extraction and rapid quantitative determination of active ingredients in Taraxacum kok-saghyz Rodin by ultra-high-performance liquid chromatography tandem mass spectrometry

Taraxacum kok-saghyz Rodin (TKS) is a promising crop that can produce rubber and also contains other active ingredients such as pentacyclic triterpenoid and sterol secondary metabolites. Our aims is to provide a rapid extraction and sensitive ultra-high-performance liquid chromatography tandem mass spectrometric method for the determination of pentacyclic triterpenoids (α-amyrin, β-amyrin, lupeol, and taraxasterol) and sterols (campesterol, stigmasterol, and β-sitosterol) in TKS. We also compared the difference in content of target compounds between TKS and Taraxacum officinale (TO). Response surface methodology (RSM) with Box–Behnken Design (BBD) was employed to optimize liquid-to-material ratio, microwave power, and ultrasonic power to improve the yield of target compounds. Target compounds were separated by a Waters ACQUITY UPLC BEH C18 column and were identified by atmospheric pressure chemical ionization-mass spectrometry. Under optimal conditions (liquid-to-solid ratio of 45 mL/g, microwave power of 420 W, and ultrasonic power of 560 W), the recoveries for target compounds were from 72.63% to 95.94%. The intra/inter-day precision was lower than 5.5%. The limits of detection and quantitation of target compounds were 0.5–5.0 ng/g and 1.0–10.0 ng/g, respectively. The developed method successfully extracted and analyzed the target compounds in TKS. The content of target compounds in TKS (9.44 mg/g) was significantly higher than that in TO (3.35 mg/g). We found that TKS is an excellent species of the Taraxacum genus, which is rich in not only latex rubber but also pentacyclic triterpenes and sterols.