Characterization and Traceability of a Vitamin K ₁ Matrix Certified Reference Material Using Heart-Cutting Two-Dimensional Liquid Chromatography

Accurately quantifying vitamin K1 (VK1) within complex matrixes continues to be both challenging and of great importance. Herein, we develop a certified reference material (CRM GBW10332) for the accurate quantification of VK1 in infant formula using heart-cutting two-dimensional liquid chromatography with ultraviolet detection. An optimized sample pretreatment step based on hydrolysis and the liquid–liquid extraction process was established to efficiently isolate VK1 from the complex matrix. The certified value of VK1 in CRMs was also assigned using ultraperformance liquid chromatography coupled with isotope dilution tandem mass spectrometry. Impressively, two independent analytical approaches demonstrated excellent consistency. Resultantly, the certified value of VK1 in CRM was 643 ± 60 μg/kg (k = 2). Moreover, the as-developed CRMs were homogeneous and possessed good stability and were maintained well for 17 months at −80 °C and 7 days at 60 °C. More importantly, the VK1 CRMs effectively address reliable tools for quality control, method validation, and proficiency testing.