title: Solidified floating organic drop microextraction for speciation of selenium and its distribution in selenium-rich tea leaves and tea infusion by electrothermal vapourisation inductively coupled plasma mass spectrometry.
abstract: Solidified floating organic drop microextraction was combined with electrothermal vapourisation inductively coupled plasma mass spectrometry for Se species in Se-rich tea leaves and tea infusion, including total, suspended, soluble, organic and inorganic Se as well as Se(IV) and Se(VI). Ammonium pyrrolidinedithiocarbamate was used as both chelating reagent and chemical modifier in this study. Se(IV) and Se(VI) were separated at pH range of 2.0-5.0. An enrichment factor of 500 was obtained for Se(IV) from this method. Under the optimum conditions, the detection limits for Se(IV) and Se(VI) were 0.19 and 0.26pgmL(-1), respectively. The relative standard deviations were less than 5.5% (c=0.1ngmL(-1), n=9). This method was applied for Se species, its content and distribution in Se-rich tea leaves and tea infusion with satisfactory results. The recoveries of spike experiments are in the range of 92.2-106%. A certified reference material of tea leaves was analyzed by this method, and the results were in agreement with certified values.
authors.affiliation: College of Chemical and Environmental Engineering, Wuhan Polytechnic University, 68 Xuefu South Road, Changqing Garden, Wuhan 430023, PR China. Electronic address: chenshizhong62@163.com.
authors.forename: Shizhong
authors.initials: S
authors.lastname: Chen
authors.affiliation: College of Chemical and Environmental Engineering, Wuhan Polytechnic University, 68 Xuefu South Road, Changqing Garden, Wuhan 430023, PR China.
authors.forename: Shengping
authors.initials: S
authors.lastname: Zhu
authors.affiliation: College of Chemical and Environmental Engineering, Wuhan Polytechnic University, 68 Xuefu South Road, Changqing Garden, Wuhan 430023, PR China.
authors.forename: Dengbo
authors.initials: D
authors.lastname: Lu
mesh_terms: D028241:Camellia sinensis / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D018515:Plant Leaves / Q000737:chemistry; D018036:Selenium Compounds / Q000737:chemistry* / Q000302:isolation & purification*; D052617:Solid Phase Microextraction / Q000379:methods*; D013662:Tea / Q000737:chemistry*; D014835:Volatilization
chemical_list: D018036:Selenium Compounds; D013662:Tea
keywords: Electrothermal vapourisation; Inductively coupled plasma mass spectrometry; Selenium-rich tea leaves; Solidified floating organic drop microextraction; Speciation of selenium and its distribution