Volume: 4, 2025
4th International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: H015
DOI: https://doi.org/10.24326/ICDSUPL4.H015
Published online: 9 April 2025
ICDSUPL, 4, H015 (2025)
Development and optimization of a method for determining melamine and cyanuric acid in milk and dairy products using liquid chromatography with mass spectrometry (LC-MS/MS)
Paulina Osowska1*, Krzysztof Tutaj1, Bartosz Sołowiej2, Katarzyna Ognik1, Anna Stępniowska1
1 Department of Biochemistry and Toxicology, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin, Poland
2 Department of Dairy Technology and Functional Food, University of Life Sciences in Lublin, Skromna 8, 20-704 Lublin, Poland
* Corresponding author: paulina.osowska@up.lublin.pl
Abstract
Melamine (MEL), a toxic compound, must be controlled in food, particularly in milk and milk-based products. It is primarily caused by its use in the synthesis of melamine-formaldehyde resins, which are used to produce laminates and plastics, as a food contact material. It can also occur as a vestigial contaminant in nitrogen supplements used in animal feed. Melamine is often combined with cyanuric acid (CA). Cyanuric acid is a naturally occurring impurity in melamine and may be formed as a byproduct during melamine synthesis. The study aimed to develop and optimize a method for determining MEL and CA in milk and dairy products using high-performance liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS). 96 samples of milk and 54 samples of milk powder (including infant formula) available commercially were purchased in grocery stores and pharmacies in Poland. A LC-MS/MS method has been optimized for the determination of MEL and CA in milk and milk-based products. Sample preparation included homogenization and addition of a suitable solvent to precipitate proteins and simultaneous extractions of melamine and cyanuric acid. Acetonitrile was selected for extraction and added in a volume ratio of 7:3 (ACN:H2O) to achieve a final percentage of organic solvent of 70%. LC-MS/MS analyzes the clear supernatant in MRM mode (i.e., multiple reaction monitoring), which was optimized for both compounds to generate sensitive transitions (127,0→85,1, 127→68,0 for MEL in positive ion mode and 128,0→42,1, 128,0→85,2 for CA in negative ion mode). Isotope-labeled internal standards MEL13C3 and CA13C3 are applied to correct for variations in sample preparation and instrument response in mass spectrometry. Both compounds are examined in the same chromatographic program using a zwitterionic HILIC LC column. Linearity was demonstrated for both compounds in the range 0.1–2 mg/L. Neither CA nor MEL was confirmed in the matrix blanks above the limit of detection (LOD). Only traces of melamine and cyanuric acid were detected in one sample of carton milk, but the concentrations were below the limit of quantification.
Keywords: melamine, cyanuric acid, liquid chromatography, milk, mass spectrometry
How to cite
P. Osowska, K. Tutaj, B. Sołowiej, K. Ognik, A. Stępniowska, 2025. Development and optimization of a method for determining melamine and cyanuric acid in milk and dairy products using liquid chromatography with mass spectrometry (LC-MS/MS) In: 4th International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL4.H015