The Novel Method of Extraction and Analysis of Melamine in Whole Milk Using Sand Material Cleanup Technique and Inertsil C18 Column by LC-MS/MS

A simple, precise, accurate and validated Liquid chromatography and Tandem mass spectrometric (LC-MS/MS) method is developed for the analysis of melamine in whole milk. Because of melamine?s basic and polar nature, a cation exchange natural sand material is used as cleanup technique. As a result, enhancement in recovery, sensitivity and selectivity has been observed as well made the analysis much cheaper by replacement of use of cartridge. A simple extraction of melamine with phosphate buffer (in acidic condition) and Acetonitrile (precipitation of the protein), matrix cleanup using silica based strong cationic exchangers (sand) and reconstitution with 0.1% Formic acid (v/v) in Acetonitrile. The separation is performed on a Inertsil ODS-3C18 column (150mm x 4.6mm x 3?m. Two selected reaction monitoring (SRM) transitions are monitored for Melamine. After optimization of instrument parameter and settings, the linear response (r2greater than0.999) is observed for samples ranging from 0.50 to 10 ?g/kg. The method provides recoveries of 70-120% in the concentration range of 0.50 to 10 ?g/kg, intra- and inter-day variation in less than2.5% RSD. The limit of detection (LOD) and limit of quantification (LOQ) values are 0.2 and 0.6 ?g/kg, respectively with an uncertainty of ? 0.03?g/kg at 95 % confidence level.