This application note describes methods for analyzing the levels of melamine and cyanuric acid in pet food and related raw materials using the Agilent 7890A-5975C GC/MS and 1200SL-6410 Triple Quadrupole LC/MS. The GC/MS method employs extraction and then trimethylsilyl derivatization and is used here for screening. The detection limit is 10 µg/g. The LC/MS/MS method requires only extraction and then a simple isocratic elution on a normal-phase silica column (Rx-Sil) with water and acetonitrile mobile phase containing 5 mM ammonium acetate. The separation of the two compounds takes 5 min. The linear range is from 50 pg/mL to 50 ng/mL for melamine and from 1 ng/mL to 100 ng/mL for cyanuric acid. The LC/MS/MS method is demonstrated by analysis of the target compounds in complex food matrix.
This application note describes a total solution for the analysis of melamine and cyanuric acid in pet food and related raw materials. It presents two methods: a screening method using GC/MS with trimethylsilyl derivatization and a confirmation/quantitation method using aqueous normal-phase LC/MS/MS without derivatization. The LC/MS/MS method offers higher sensitivity and selectivity, covering trace-level analysis in animal fluids to high levels in food matrices.
The document provides detailed experimental procedures, including sample preparation protocols for both GC/MS and LC/MS/MS. It specifies instrument conditions, column types, mobile phases, and mass spectrometry parameters (SIM for GC/MS and MRM for LC/MS/MS). Results demonstrate the linearity, detection limits, and performance of the methods on various food matrices such as pet food, wheat gluten, and corn meal.
| GC/MS Detection Limit | 10 ug/g |
|---|---|
| LC/MS/MS Linear Range Melamine | 50 pg/mL to 50 ng/mL |
| LC/MS/MS Linear Range Cyanuric Acid | 1 ng/mL to 100 ng/mL |
| LC/MS/MS Separation Time | 5 min |
| GC/MS Column | DB-5MS 30 m x 0.25 mm x 0.25 ym |
| LC/MS/MS Column | ZORBAX Rx-Sil, 2.1 mm x 150 mm, 5 ym |
| LC/MS/MS Injection Volume | 10 pL |
| LC/MS/MS Source Temperature | 350°C |
The detection limit for the GC/MS screening method is 10 ug/g.
No, the LC/MS/MS method requires only extraction and then a simple isocratic elution without derivatization.
The method uses water and acetonitrile mobile phase containing 5 mM ammonium acetate.
The analysis uses MassHunter B.01.03 software.