Method development and validation for melamine and its derivatives in rice concentrates by liquid chromatography. Application to animal feed samples

Abstract

An isocratic LC method for the determination of melamine and its degradation products (ammelide, ammeline, and cyanuric acid), used to increase the apparent protein content of rice protein concentrate, has been developed. Method development involved optimization of different RP columns, aqueous mobile phases, pH, phosphate concentration, and temperature. The optimum separation of these compounds was achieved using a Luna CN column (30 degrees C), 5 mmol L(-1) sodium phosphate (pH 5.0) as mobile phase, 1 mL min(-1) flow-rate, UV absorbance-DAD detection at 220 nm, and resorcine as internal standard; this enabled separation of these compounds with baseline resolution (values in the 2.1-10.1 range) in about 8 min. Prior to HPLC, the developed sample preparation procedure consisted in a leaching process using the above mentioned mobile phase. Method validation was carried out in rice protein concentrates in accordance with the European Commission decision 2002/657/EC criteria. For this purpose, eight mandatory performance characteristics for the conventional validation approach were determined: calibration graphs, extraction efficiencies, decision limits, detection capabilities, precision (repeatability and within-laboratory reproducibility), accuracy, selectivity, and robustness. The extraction efficiencies for these compounds were in the range 99-100% and the within-laboratory reproducibility at 1.0, 1.5, and 2.0 detection capabilities concentration levels were smaller than 5, 4, and 3%, respectively. Finally, the proposed method was successfully applied to the analysis of other rice protein concentrates and several animal feed samples.

LC‐MS/MS method for the determination of melamine in rat plasma: Toxicokinetic study in Sprague–Dawley rats

“…GC [15,16], LC (HPLC-UV) [17,18], LC-MS/MS [19 -24], and CE [25 -27] have been developed for the analysis of melamine in lots of matrices, such as soil, animal feeds, animal tissues, plant matter, raw milk, and dairy products. To the best of our knowledge, there are only two in vivo PK study in mammalian species.…”

Rapid detection of melamine with 4-mercaptopyridine-modified gold nanoparticles by surface-enhanced Raman scattering

“…Currently, various methods-including thin-layer chromatography [6], gas chromatography (GC) [7,8], high-performance liquid chromatography [9][10][11][12], enzyme-linked immunosorbent assay technology [13], matrix-assisted laser desorption/ ionization mass spectrometry (MALDI-MS) [14], and surface desorption atmospheric pressure chemical ionization mass spectrometry [15]-have been used to detect melamine in food. However, these methods usually suffer from drawbacks, such as the need for a complicated sample preparation process, clean-up steps, and a time-consuming determination process, so they cannot fulfill the requirement for fast in situ detection.…”

Applicability of Liquid Chromatography with Time-of-Flight Mass Spectrometric Detection for Determination of Cyanuric Acid in Soil

“…The HPLC-UV methods using the modified silica or porous graphitic carbon columns, phosphate buffer eluents, and UV detection at wavelengths of 200 nm to 220 nm have been developed for determining CA in water, 1,15,16 cereal flours, 17 pet food, 18 and animal feed samples. 19 The UV-detection has also been applied for the determination of free CA in nylon by ion-exclusion chromatography. 20 However, due to the coeluting interferences absorbing UV light below 220 nm, UV detection of CA is often not sufficiently selective.…”