title: Cloud point extraction with/without chelating agent on-line coupled with inductively coupled plasma optical emission spectrometry for the determination of trace rare earth elements in biological samples.
abstract: The on-line incorporation of cloud point extraction (CPE) with/without 8-hydroxyquinoline (8-Ox) as chelating agent into flow injection analysis associated with inductively coupled plasma optical emission spectrometry (ICP-OES) for determining trace rare earth elements (REEs) is presented and evaluated. The significant parameters affecting on-line cloud point extraction of REEs such as sample pH, flow rate, 8-Ox concentration, Triton X-114 concentration were systematically studied. Under the optimized conditions, with the consumption of 3.0 mL sample solution, the limits of detection (3 sigma) were ranged from 41.4 pg mL(-1) (Yb) to 448 pg mL(-1) (Gd) with relative standard deviations (RSDs) of 1.0% (Eu)-5.9% (Sm) for on-line CPE-ICP-OES with 8-Ox as chelating agent, and 69.0 pg mL(-1) (Sc) to 509.5 pg mL(-1) (Sm) with RSDs of 2.9% (Yb)-7.5% (Ho) for on-line CPE-ICP-OES without 8-Ox as chelating agent, respectively. The sample throughput of 17samples h(-1) was obtained for both systems. The developed methods of on-line CPE-ICP-OES were validated by the analysis of certified reference material (GBW07605, tea leaves) and real biological samples of pig liver, Auricularia auricula and mushroom.
authors.affiliation: Department of Chemistry, Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Wuhan University, Wuhan 430072, China.
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Hu
mesh_terms: D002614:Chelating Agents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008674:Metals, Rare Earth / Q000032:analysis*; D012015:Reference Standards; D013057:Spectrum Analysis / Q000379:methods*; D013696:Temperature; D014131:Trace Elements / Q000032:analysis*
chemical_list: D002614:Chelating Agents; D008674:Metals, Rare Earth; D014131:Trace Elements