An LC–MS/MS method for quantitation of cyanidin‐3‐O‐glucoside in rat plasma: Application to a comparative pharmacokinetic study in normal and streptozotocin‐induced diabetic rats

A sensitive and reliable liquid chromatography tandem mass spectrometry (LC–MS/MS) method was developed to determine cyanidin‐3‐O‐glucoside (Cy‐3G) in normal and streptozotocin‐induced diabetic rat plasma. Chromatographic separation was carried out on a Zorbax SB‐C18 (50 × 4.6 mm, 5 μm) column and mass spectrometric analysis was performed using a Thermo Finnigan TSQ Quantum Ultra triple‐quadrupole mass spectrometer coupled with an ESI source in the negative ion mode. Selected reaction monitoring mode was applied for quantification using target fragment ions m/z 447.3 → 285.2 for Cy‐3G and m/z 463.0 → 300.1 for quercetin‐3‐O‐glucoside (internal standard). The calibration curve was linear over the range 3.00–2700 ng/mL (r2 ≥ 0.99) with the lower limit of quantitation at 3.00 ng/mL. Intra‐ and inter‐day precision was