Dispersant-First Dispersive Liquid-Liquid Microextraction (DF-DLLME), a Novel Sample Preparation Procedure for NDMA Determination in Metformin Products

On‐column trace‐level formation of N‐nitrosamine in a liquid chromatography–mass spectrometry analytical system

“…3 Such limits can necessitate the development of novel sample extraction techniques such as dispersant-first dispersive liquid-liquid microextraction. 11 These N-nitrosamine impurities also have a high potential for interference from other small molecules. A good example of this is the case of dimethylformamide interference in the determination of NDMA concentration in metformin analysis detailed by Yang et al 12 (see also Fritzsche et al 13 ); analytical errors such as these can be reasonably expected to undermine confidence in medicines and thus negatively impact patient well-being.…”