Bioanalytical HPLC-UV Determination of Dopamine in Plasma and Mouse Brain Homogenate with Greenness, Whiteness, and Blueness Assessment

Dopamine dysregulation is connected to several neurological disorders, including Parkinson’s disease, Huntington’s disease, and addiction. A new, precise, accurate, and specific reversed-phase high-performance liquid chromatographic method was developed for dopamine determination in different biological media (human/mouse plasma and mouse brain homogenate). The chromatographic assay was performed using Avantor ACE® RP-18 (250 × 4.6 mm, 5 µm) column equipped with a suitable ODS pre-column. The temperature was ambient, and the mobile phase was composed of 10 mM potassium dihydrogen phosphate buffer (pH = 3) with 0.25 g/L sodium octanesulfonate, methanol, and acetonitrile at a volume-to-volume ratio of 75:20:5. Isocratic elution mode, flow rate 1.0 mL/min, and ultraviolet detection (280 nm) were applied. The procedure was validated for linearity, and all calibration curves were linear over the selected range with determination coefficients greater than 0.998. Intraday repeatability, expressed as the coefficient of variation, did not exceed 4.88% for the plasma and 3.32% for the mouse brain homogenate samples across all tested concentration levels. The proposed chromatographic method was evaluated in terms of greenness, whiteness, and blueness using three ecological metrics (the Analytical Greenness software, White Analytical Chemistry model, and Blue Applicability Grade Index). The optimized procedure was proven to be suitable for implementation in the routine analytical practice.