Quantification of menadione from plasma and urine by a novel cysteamine-derivatization based UPLC-MS/MS method.

Menadione, as the crucial component of vitamin Ks, possessed significant nutritional and clinical values. However, there was still lack of favourable quantification strategies for it to date. For improvement, a novel cysteamine derivatization based UPLC-MS/MS method was presented in this work. The derivatizating reaction was proved non-toxic, easy-handling and high-efficient, which realized the MS detection of menadione under positive mode. Benefitting from the excellent sensitivity of the derivatizating product as well as the introduction of the stable isotope dilution technique, the quantification could be achieved in the range of 0.05-50.0ng/mL for plasma and urine matrixes with satisfied accuracy and precision. After analysis of the samples from healthy volunteers after oral administration of menadione sodium bisulfite tablets, the urinary free menadione was quantified for the very first time. We believe the progress in this work could largely promote the exploration of the metabolic mechanism of vitamin K in vivo.