title: [Rapid determination of fatty acids in Ranunculus ternatus Thunb by microwave-ultrasonic synergistic one-step extraction-derivatization and gas chromatography-mass spectrometry].
abstract: A rapid and simple microwave-ultrasonic synergistic one-step extraction-derivatization (MUED) method and gas chromatography-mass spectrometry was established for the determination of low content fatty acids (FAs) profile in Ranunculus ternatus Thunb. The critical experimental parameters for MUED method were optimized with response surface methodology by taking the chromatographic peak areas of total FAs as a major response index. The best technological parameters were determined as 5.0 g of Ranunculus ternatus Thunb. powder, 50.0 mL of n-hexane, 500 W of microwave power, 50 degree C of reaction temperature, 0.30 g of catalyst (KOH), 4.0 mL of derivatization reagent (methanol) and the time of extraction-derivatization of 8 min. The contents of individual FAs were quantified by internal standard method. The results showed that the chromatographic peak areas of the total FAs and the total unsaturated FAs contents obtained with MUED were (3.327 +/- 0.023) x 10(7) (n = 3) and (13.59 +/- 0.30) mg/g (n = 3) respectively. They were markedly higher than those obtained by the conventional method which were (2.410 +/- 0.036) x 10(7) (n = 3) and (12.05 +/- 0.34) mg/g (n = 3) respectively. The MUED method simplified the complicated sample handling steps, shortened the sample preparation time, reduced the cost of analysis, and improved the extraction and derivatization efficiency of the lipids, especially weakened the oxidization and decomposition of the unsaturated FAs. The simplicity, speed and practicability suggest the proposed method has significant potential for the determination of lowcontent FAs in herbal medicines.
authors.affiliation: Key Laboratory of Medicinal Resource and Natural Pharmaceutical Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi' an 710100, China.
authors.forename: Hanying
authors.initials: H
authors.lastname: Zhan
authors.forename: Ruilin
authors.initials: R
authors.lastname: Liu
authors.forename: Dejin
authors.initials: D
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
authors.forename: Shengjie
authors.initials: S
authors.lastname: Xu
authors.forename: Zhiqi
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D005227:Fatty Acids / Q000032:analysis* / Q000302:isolation & purification; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D008872:Microwaves; D031947:Ranunculus / Q000737:chemistry*; D014465:Ultrasonics
chemical_list: D005227:Fatty Acids