title: Application of a thiourea-containing task-specific ionic liquid for the solid-phase extraction cleanup of lead ions from red lipstick, pine leaves, and water samples.
abstract: Here, task-specific ionic liquid solid-phase extraction is proposed for the first time. In this approach, a thiourea-functionalized ionic liquid is immobilized on the solid sorbent, multiwalled carbon nanotubes. These modified nanotubes packed into a solid-phase extraction column are used for the selective extraction and preconcentration of ultra-trace amounts of lead(II) from aqueous samples prior to electrothermal atomic absorption spectroscopy determination. The thiourea functional groups act as chelating agents for lead ions retaining them and so, give the selectivity to the sorbent. Elution of the retained ions can be performed using an acidic thiourea solution. The effects of experimental parameters including pH of the aqueous solution, type and amount of eluent, and the flow rates of sample and eluent solutions on the separation efficiency are investigated. The linear dependence of absorbance of lead on its concentration in the initial solution is in the range of 0.5-40.0 ng/mL with the detection limit of 0.13 ng/mL (3(Sb)/m, n = 10). The proposed method is applicable to the analysis of red lipstick, pine leaves, and water samples for their lead contents.
authors.affiliation: Department of Chemistry, Faculty of Science, Shahid Bahonar University of Kerman, Kerman, Iran; Young Research Society, Shahid Bahonar University of Kerman, Kerman, Iran.
authors.forename: Asma
authors.initials: A
authors.lastname: Saljooqi
authors.forename: Tayebeh
authors.initials: T
authors.lastname: Shamspur
authors.forename: Maryam
authors.initials: M
authors.lastname: Mohamadi
authors.forename: Ali
authors.initials: A
authors.lastname: Mostafavi
mesh_terms: D000327:Adsorption; D003358:Cosmetics / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry; D007854:Lead / Q000032:analysis / Q000302:isolation & purification*; D057230:Limit of Detection; D028223:Pinus / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D013057:Spectrum Analysis; D013890:Thiourea / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D003358:Cosmetics; D052578:Ionic Liquids; D014874:Water Pollutants, Chemical; D007854:Lead; D013890:Thiourea
keywords: Ionic liquids; Lead; Pine leaf; Red lipstick; Solid-phase extraction