title: Continuous determination of total flavonoids in Platycladus orientalis (L.) Franco by dynamic microwave-assisted extraction coupled with on-line derivatization and ultraviolet-visible detection.
abstract: This paper describes a new method for the determination of total flavonoids in Platycladus orientalis (L.) Franco. The method was based on dynamic microwave-assisted extraction (DMAE) coupled with on-line derivatization and ultraviolet-visible (UV-vis) detection. The influence of the experimental conditions was tested. Maximum extraction yield was achieved using 80% aqueous methanol of extraction solvent; 80 W of microwave output power; 5 min of extraction time; 1.0 mL min(-1) of extraction solvent flow rate. The derivatization reaction between aluminium chloride and flavonoid is one of the most sensitive and selective reactions for total flavonoids determination. The optimized derivatization conditions are as follows: derivatization reagent 1.5% aluminium chloride methanol solution; reaction coil length 100 cm; derivatization reagent flow rate 1.5 mL min(-1). The detection and quantification limits obtained are 0.28 and 0.92 mg g(-1), respectively. The intra-day and inter-day precisions (R.S.D.) obtained are 1.5% and 4.6%, respectively. Mean recovery is 98.5%. This method was successfully applied to the determination of total flavonoids in P. orientalis (L.) Franco and compared with heat reflux extraction. The results showed that the higher extraction yield of total flavonoids was obtained by DMAE with shorter extraction time (5 min) and small quantity of extraction solvent (5 mL).
authors.affiliation: College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
authors.forename: Ligang
authors.initials: L
authors.lastname: Chen
authors.forename: Lan
authors.initials: L
authors.lastname: Ding
authors.forename: Aimin
authors.initials: A
authors.lastname: Yu
authors.forename: Ruilan
authors.initials: R
authors.lastname: Yang
authors.forename: Xiupin
authors.initials: X
authors.lastname: Wang
authors.forename: Jiantao
authors.initials: J
authors.lastname: Li
authors.forename: Haiyan
authors.initials: H
authors.lastname: Jin
authors.forename: Hanqi
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000077410:Aluminum Chloride; D017607:Aluminum Compounds / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry; D029779:Cupressaceae / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis*; D000432:Methanol / Q000737:chemistry; D008872:Microwaves; D015394:Molecular Structure; D009862:Online Systems; D010936:Plant Extracts / Q000737:chemistry; D012680:Sensitivity and Specificity; D012996:Solutions / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
chemical_list: D017607:Aluminum Compounds; D002712:Chlorides; D005419:Flavonoids; D010936:Plant Extracts; D012996:Solutions; D000077410:Aluminum Chloride; D000432:Methanol