Ultrasonic-Assisted Solid-Phase Extraction Pre-concentration and Determination of Nicotinamide and Nicotinic Acid by High-Performance Liquid Chromatography Using Anthracite

This study introduces a novel method of ultrasonic-assisted solid-phase extraction, pre-concentration, and reversed-phase high-performance liquid chromatography to determine nicotinamide (NAM) and nicotinic acid (NAC) from an aqueous solution using anthracite particles (ANTCs). Results demonstrated that ANTCs were quite efficient for use in extraction and pre-concentration of traces of NAM and NAC at 25 °C. Tests investigated the effects of the parameters: pH, buffer and its volume, electrolyte concentration, composition and volume of the desorbing solvent, accepted tolerable volume, amount of adsorbent, ultrasonic radiation time, and evidence of some co-existing ions on pre-concentration and determinations of NAM and NAC. The method showed good linearity for determination of these compounds in the range of 0.0025–10 μg mL⁻¹ with regression coefficients of 0.999. Evaluations for limits of detection were 6 × 10⁻⁴ and 7 × 10⁻⁴ μg mL⁻¹ for NAM and NAC, respectively. Intra- and inter-day relative standard deviations for 0.2 and 5 μg mL⁻¹ were below 3.5 % and 4.6 %, respectively. Samples of rice, coffee, spice, spaghetti, tea, and B-complex syrup with potential niacin content were used as real samples, and NAM and NAC in the samples and spiked samples were pre-concentrated and determined successfully.