کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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743271 | 894348 | 2009 | 7 صفحه PDF | دانلود رایگان |
A polymeric membrane ion-selective electrode for determination of melamine is described in this paper. It is based on a molecularly imprinted polymer (MIP) for selective recognition, which can be synthesized by using melamine as a template molecule, methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linking agent. The membrane electrode shows near-Nernstian response (54 mV/decade) to the protonated melamine over the concentration range of 5.0 × 10−6 to 1.0 × 10−2 mol L−1. The electrode exhibits a short response time of ∼16 s and can be stable for more than 2 months. Combined with flow analysis system, the potentiometric sensor has been successfully applied to the determination of melamine in milk samples. Interference from high concentrations of ions co-existing in milk samples such as K+ and Na+ can be effectively eliminated by on-line introduction of anion- and cation-exchanger tandem columns placed upstream, while melamine existing as neutral molecules in milk of pH 6.7 can flow through the ion-exchanger columns and be measured downstream by the proposed electrode in an acetate buffer solution of pH 3.7.
Journal: Sensors and Actuators B: Chemical - Volume 141, Issue 2, 7 September 2009, Pages 544–550