Molecularly imprinted polymer as SPE sorbent for selective extraction of melamine in dairy products.
In this paper, a highly selective sample cleanup procedure combining molecular imprinting and solid-phase extraction (MI-SPE) was developed for the isolation of melamine in dairy products. The molecularly imprinted polymer (MIP) was prepared using melamine as the template molecule, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking monomer. The melamine imprinted polymer was used as selective sorbent for the solid-phase extraction of melamine from dairy products. An off-line MI-SPE method followed by high-performance liquid chromatography with diode-array detection for the detection of melamine was also established. The mean recoveries of melamine from ultra-heat treatment (UHT) milk and milk powders were 92.9-98.0% and 91.6-102.8%, respectively. Good linearity was obtained from 0.5 microM to 10 microM (r>0.999) with a quantitation limit of 0.5 micromol/L (0.06 ppm) which was sufficient to analyse melamine at the maximum level permitted by U.S. Food and Drug Administration (1 ppm) in dairy products. It was demonstrated that the proposed MI-SPE-HPLC method could be applied to direct determination of melamine in dairy products.
Yang
Huang-Hao
HH
The Key Lab of Analysis and Detection Technology for Food Safety of the MOE, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou, PR China. hhyang@fio.org.cn
Zhou
Wen-Hui
WH
Guo
Xiu-Chun
XC
Chen
Fa-Rong
FR
Zhao
Heng-Qiang
HQ
Lin
Li-Ming
LM
Wang
Xiao-Ru
XR
D000327:Adsorption; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003611:Dairy Products / Q000032:analysis; D008689:Methacrylates / Q000737:chemistry; D008892:Milk / Q000737:chemistry*; D054802:Molecular Imprinting; D011108:Polymers / Q000737:chemistry*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization; D014227:Triazines / Q000737:chemistry / Q000302:isolation & purification*
D008689:Methacrylates; D011108:Polymers; D014227:Triazines; C008384:methacrylic acid; C004919:ethylene dimethacrylate; C011907:melamine