Rapid method for quantification of anthocyanidins and anthocyanins in human biological samples

Using simple solvent extraction and enzymatic hydrolysis, a rapid LC-MS/MS method for quantification of free and conjugated forms of anthocyanidins and anthocyanins in plasma and urine samples was developed and validated. A mixed enzymatic treatment containing β-glucuronidase (100 U mL^-1) and sulfatase (2.5 U mL^-1) for 5 min (37 °C; pH 6) was optimal condition for deconjugation of anthocyanidins and anthocyanins in urine and plasma samples. The LC-MS/MS allowed quantifying thirteen different anthocyanidins and anthocyanins simultaneously. The developed LC-MS/MS method was precise and accurate over multiple days and nominal concentrations. The stability assessment study confirmed that the long-term storage and/or periodic use of plasma and urine samples might have a considerable impact on the stability of some anthocyanidins. The method was successfully applied to measure anthocyanidins and anthocyanins in plasma and urine samples following consumption of acute blueberry test meals.