Comparative Evaluation of Capillary Electrophoresis and Flame Photometry for Sodium, Potassium and Calcium Determination in Bone Broth

This study aimed to optimize and validate a capillary electrophoresis (CE) method for the quantification of sodium, potassium, and calcium in bone broth and to compare with flame photometry (FP). Separation conditions of cations were optimized using response surface methodology considering the influence of temperature (13-27 oC) and voltage (13-27 kV). It has been found that the optimal conditions (18 oC and 20 kV) provided a high theoretical plate number (efficiency) and resolution with acceptable migration times. CE showed higher linearity (R2 >0.998) and lower limits of detection (1.50-3.46 µg/mL) than FP (3.23-10.5 µg/mL). In terms of precision, the FP showed better intra-day repeatability, whereas CE showed better inter-day repeatability, particularly for K+. Recovery values of cations determined in both methods ranged from 93.7% to 109%. When applied to bone broth samples, no significant differences were observed between CE and FP (p >0.05). Na+ was the most abundant mineral, with concentrations of 1037 and 1049 µg/mL determined by FP and CE, respectively, followed by K+ (166 and 158 µg/mL) and Ca2+ (67.3 and 64.2 µg/mL). Overall, the results showed that CE is a reliable, sensitive, and environmentally friendly alternative to FP for the determination of mineral cations in food matrices.