title: Single-run electrochemical determination of melamine in dairy products and pet foods.
abstract: A simple electrochemical approach, which does not require any expensive and complex instruments, is established for the selective and quantitative recognition of melamine in diary products and pet foods. During a preconcentration step (at 1.8 V versus Ag/AgCl), the formation of a polymer film from melamine on a preanodized screen-printed carbon electrode was identified by SEM and XPS. The as-formed polymer was found to be electroactive with a reversible redox peak, and hence square-wave voltammetry was applied to further increase the detection sensitivity to meet the detection limit for application in real sample analysis. Simply with a medium exchange procedure, melamine was selectively detected with a detection limit (S/N=3) of 0.8 μM (i.e., 98.3 ppb) by square-wave voltammetry. Lower than 1 ppm of melamine in real samples can be easily detected with good recoveries of 98.7-100.9% by the proposed approach. The recovery tests established for external calibration and standard addition techniques verified that the analysis can be done in a single-run measurement.
authors.affiliation: Department of Chemistry, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 402, Taiwan.
authors.forename: Chen-Wei
authors.initials: CW
authors.lastname: Liao
authors.forename: Yue-Ru
authors.initials: YR
authors.lastname: Chen
authors.forename: Jen-Lin
authors.initials: JL
authors.lastname: Chang
authors.forename: Jyh-Myng
authors.initials: JM
authors.lastname: Zen
mesh_terms: D000818:Animals; D003611:Dairy Products / Q000032:analysis*; D055664:Electrochemical Techniques / Q000379:methods*; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000032:analysis; D007231:Infant, Newborn; D057805:Pets; D014227:Triazines / Q000032:analysis*
chemical_list: D014227:Triazines; C011907:melamine