"Melamine" has not faded out of people's memories. Another incident of non-protein amine residues in dairy products has become a hot topic recently. Non-protein amine substances are a general term for substances with high nitrogen content and stable properties such as urea, biuret, and dicyandiamide. Based on the determination method of protein content stipulated by the current national standard-Kjeldahl method, such residues in food will be converted into protein content. If the detection of such substances cannot be given enough attention, it will endanger the development of related industries and become a hidden danger to human health.
Braunway integrates global resources and provides a full set of analysis and detection solutions, especially suitable for the detection of such substances in high-protein foods such as dairy products, soy milk and eggs.
1. Sample preparation
Weigh 0.5-1.0 g of sample and 10 mL centrifuge tube with stopper, add 3.0 mL of warm water ultrasound, then add 7.0 mL of acetonitrile, vortex, freeze and centrifuge at 6000r / min at -10 Â° C for 20 min, draw 5.0 mL of clear solution , Nitrogen was blown dry, reconstituted with 1.0 mL 70% acetonitrile solution, and passed 0.45 Î¼m organic phase filter membrane.
2. Chromatographic analysis conditions
Column: C18 liquid column (250 mm Ã— 4.6 mm, 5 Î¼m)
Injection volume: 10 Î¼L
Flow rate: 1.0 mL / min
Detection wavelength: 203 nm
Mobile phase: A is 0.2 mmol / L ammonium acetate (pH 4.0); B is acetonitrile
3. Mass spectrometry conditions
Electrospray ionization ESI positive ion mode, electrospray voltage: 4000 V, sheath gas pressure: 30 psi, auxiliary gas pressure: 5 psi, scan mode MRM
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