Recently, New Zealand milk and milk products have been detected to contain low levels of the toxic substance dicyandiamide. The New Zealand government has ordered a ban on the sale of milk products containing dicyandiamide. Domestic dairy product manufacturers and government regulatory agencies have also begun to establish corresponding analysis methods.
The main difficulties of the dicyandiamide detection method are:
Pre-treatment: The method of melamine is completely unsuitable, the polarity of dicyandiamide is very large, and the general small column cannot be retained;
LCMS method: C18 is not reserved, HILIC method development is difficult; matrix interference is serious, interference quantitative and qualitative.
WatersÂ® now offers a corresponding complete solution, including sample preparation and LCMS method, which can quickly detect the residual dicyandiamide in dairy products.
Instruments: Waters ACQUITY UPLCÂ®, XevoÂ® TQ-S MS
Column: BEH Amide column, 2.1 * 150mm
Mobile phase A: 0.05% acetic acid in water
Mobile phase B: 0.05% acetonitrile acetate
Flow rate: 0.3mL / min; gradient elution
Column temperature: 30 â„ƒ
Solid phase extraction conditions:
Take 1g milk powder and add 10mL 1% trichloroacetic acid to dissolve and precipitate protein, centrifuge at 12,000 rpm for 10min; take 2mL supernatant and load it on Sep-PakÂ® AC2 cartridge (Sep-Pak AC2 is connected to 30mL reservoir, wat011390 ), The method recovery rate is 91%.
Conclusion: The matrix of the dairy product is more complex, and the sample can be purified and enriched by Sep-Pak AC2 solid phase extraction column; the polar molecule of dicyandiamide is very polar, and the traditional C18 column cannot be retained. Waters â€™BEH Amide chromatography The column is a propylamide stationary phase. In the HILIC mode of hydrophilic interaction chromatography, dicyandiamide has good retention and peak shape. At the same time, ACQUITY UPLC combined with Xevo TQ-S MS can achieve fast and highly sensitive analysis results.
For more information, please contact Waters Corporation Application Technology Specialist:
About Waters Corporation ()
For more than 50 years, Waters Corporation (NYSE: WAT) has provided practical and sustainable innovations that have made significant advances in the fields of medical services, environmental management, food safety, and global water quality monitoring, thus providing laboratory Institutions have created business advantages.
As the pioneer of a series of separation science, laboratory information management, mass spectrometry and thermal analysis technologies, Waters â€™major breakthroughs and laboratory solutions have created a lasting platform for customersâ€™ success.
With a revenue of $ 1.84 billion in 2012, Waters Corporation will continue to lead customers around the world to explore science and achieve outstanding achievements.
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