In this paper, we present a simple and low-cost capillary electrophoresis method for ultra-fast determination of active ingredients present in three different pharmaceutical formulations: (i) scopolamine (SCO) and dipyrone (DIP); (ii) orphenadrine (ORP), caffeine (CAF) and DIP; (iii) mepyramine (MEP), CAF, DIP, and ascorbic acid (AA). The proposed method is based on capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D). The samples can be analyzed in a single run (< 1 minute) using 10 mmol L-1 3,4-dimethoxycinnamate (DMX) and 12 mmol L-1 triethanolamine (TEA) as a background electrolyte (pH = 8.5). A linear working range (r > 0.993) was obtained from 0.10 to 0.50 mmol L-1 for SCO, from 0.25 to 1.25 mmol L-1 for ORP and MEP, from 0.50 to 2.50 mmol L-1 for DIP and CAF, and from 1.00 to 3.00 mmol L-1 for AA. The limits of detection were 0.02, 0.05, 0.03, 0.04, 0.02, and 0.06 mmol L-1 for SCO, DIP, ORP, CAF, MEP, and AA, respectively. In addition, the proposed method also provided adequate intra (< 4%) and inter-day (< 14%) precision values, as well as satisfactory recovery values for spiked pharmaceutical samples (from 92% to 103%).
capillary electrophoresis; ultra-fast analysis; metamizole; C4D; multicomponent analysis
