title: Amino-functionalized nano-size composite materials for dispersive solid-phase extraction of phosphate in water samples.
abstract: An efficient analytical method for the preconcentration and determination of phosphate in water samples at trace levels was proposed.  The method was based on sample enrichment using dispersive solid-phase extraction (dSPE) with tetraethylenepentamine (TEPA)-functionalized nano-size composite materials (TEPA-NCMs) as sorbents, which were fully characterized.  Various parameters affecting the extraction efficiency were systematically investigated.  After extraction, the post-adsorbed TEPA-NCMs were eluted by a NaOH solution for desorption of the phosphate.  The resulting eluate containing phosphate was determined by a spectrophotometric method.  The limit of detection (LOD) and the limit of quantification (LOQ) were 0.29 and 0.96 μg L(-1), respectively.  The relative standard deviations (RSDs) were lower than 8.0% with average recoveries ranging from 91 to 118%.  The present method was successfully applied to the determination of phosphate at trace levels in real water samples, and it was confirmed that the TEPA-NCMs are highly effective dSPE materials.
authors.affiliation: Ningbo Institute of Technology, Zhejiang University, PR China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shengdong
authors.initials: S
authors.lastname: Pan
authors.forename: Haoyu
authors.initials: H
authors.lastname: Shen
authors.forename: Meiqin
authors.initials: M
authors.lastname: Hu
mesh_terms: D005029:Ethylenediamines / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D010710:Phosphates / Q000302:isolation & purification*; D052616:Solid Phase Extraction; D012996:Solutions; D014867:Water / Q000737:chemistry*
chemical_list: D005029:Ethylenediamines; D010710:Phosphates; D012996:Solutions; D014867:Water; C034269:tetraethylenepentamine