Determination of salbutamol in syrups by capillary electrophoresis with contactless conductivity detection (CE-C4D)

This paper describes the separation and quantification of salbutamol in pharmaceutical products (salbutamol syrups) by capillary electrophoresis (CE) with contactless conductivity detection (C4D). The system was studied by micellar electrokinetic capillary chromatography (MEKC) and free solution capillary electrophoresis (FSCE), being the latter chosen in function of best resolution and sensitivity in comparison with the MEKC method. CE-C4D was applied to analysis of salbutamol in syrups utilizing 1.0 × 10−2 mol L−1 acetic acid/sodium acetate buffer (pH 4.9) as running electrolyte. Tetraethylammonium (TEA) solution was used as internal standard. The results obtained include a linear dynamic range from 7.0 × 10−5 to 3.0 × 10−4 mol L−1 and good repeatability (R.S.D. = 4.7% for n = 10 for a 7.0 × 10−5 mol L−1 salbutamol solution). The detection limit was calculated as 1.0 × 10−5 mol L−1 and the limit of quantification was estimated as 3.3 × 10−5 mol L−1. For syrups analysis the reproducibility presented deviations between 1.5% and 2.5% (three different days) obtained for measurements in triplicate.