Chinese Journal of Chromatography

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Determination of melamine residue in plant origin protein powders using high performance liquid chromatography-diode array detection and high performance liquid chromatography-electrospray ionization
tandem mass spectrometry

DING Tao1, XU Jinzhong1, LI Jianzhong2, SHEN Chongyu1,
WU Bin1, CHEN Huilan1, LI Shujuan2   

  1. 1.Animal, Plant and Food Inspection Center of Jiangsu Entry-Exit Inspection and Quarantine Bureau, Nanjing 210001, China;
    2.Chinese Academy of Inspection and Quarantine, Beijing 100025, China
  • Received:2007-06-22 Revised:2007-08-21 Online:2008-01-30 Published:1984-09-25

Abstract:

A method for the determination of melamine residue in plant origin protein powders was developed using high performance liquid chromatography-diode array detection (HPLC-DAD) and HPLC-electrospray ionization tandem mass spectrometry (ESI-MS/MS). HPL-DAD was used in preliminary screening of the samples for melamine, and HPLC-MS/MS was used in the confirmatory of melamine. Trichloroacetic acid solution was used to precipitate proteins and to dissociate the target analyte from the sample matrix. The supernatant was cleaned up with strong cation exchange column for HPLC-MS/MS. The HPLC-DAD separation was carried out on a C18 column (250 mm×4.6 mm, 5 μm) with 0.01 mol/L sodium n-heptanesulfate (pH adjusted to 4.5 with citric acid)-acetonitrile (90:10, v/v) as mobile phase at a flow rate of 1.0 mL/min, and detected at 240 nm. HPLC-MS/MS was performed in selected ion monitoring mode with trichloroacetic acid solution as ion pair reagent. The limits of detection were 10 mg/kg and 0.5 mg/kg for HPLC-DAD and HPLC-MS/MS, respectively. The mean recoveries were 76%-88% for HPLC-DAD and 72%-82%(matrix match calibration curve) for HPLC-MS/MS and the relative standard deviations were 3.4%-6.4% for both HPLC-DAD and HPLC-MS/MS.

Key words: high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), melamine residue, plant origin protein , high performance liquid chromatography-diode array detection (HPLC-DAD)