title: Hydrophilic solid-phase extraction of melamine with ampholine-modified hybrid organic-inorganic silica material.
abstract: In this work, an ampholine-functionalized hybrid organic-inorganic silica sorbent was successfully used to extract melamine from a milk formula sample by a hydrophilic interaction solid-phase extraction protocol. Primary factors affecting the extraction efficiency of the material such as extraction solvent, elution solvent, sample loading volume, and elution volume have been thoroughly optimized. Under the optimized hydrophilic solid-phase extraction conditions, the recoveries of melamine spiked in milk formula samples ranged from 86.2 to 101.8% with relative standard deviations of 4.1-9.4% (n = 3). The limit of detection (S/N = 3) was 0.32 μg/g. The adsorption capacity toward melamine was 30 μg of melamine per grams of sorbent. Due to its simplicity, rapidity and cost effectiveness, the newly developed hydrophilic solid-phase extraction method should provide a promising tool for daily monitoring of doped melamine in milk formula.
authors.affiliation: College of Chemical Engineering, Ningbo University of Technology, Ningbo, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Wang
authors.forename: Yiming
authors.initials: Y
authors.lastname: Zhu
authors.forename: Junfeng
authors.initials: J
authors.lastname: Ma
authors.forename: Rongrong
authors.initials: R
authors.lastname: Xuan
authors.forename: Haoqi
authors.initials: H
authors.lastname: Gao
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liang
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhang
authors.forename: Yukui
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D005506:Food Contamination / Q000032:analysis*; D057927:Hydrophobic and Hydrophilic Interactions; D041943:Infant Formula / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D014227:Triazines / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D011073:Polyamines; D011108:Polymers; D014227:Triazines; C002023:Ampholine; D012822:Silicon Dioxide; C011907:melamine
keywords: Ampholine; Hybrid silica; Hydrophilic interaction; Melamine; Solid-phase extraction