A sub-minute electrophoretic method for simultaneous determination of naphazoline and zinc.

This paper reports for the first time, a method for simultaneous determination of naphazoline (NPZ) and zinc (Zn) using an analytical separation technique (capillary electrophoresis with capacitively coupled contactless conductivity detection -CE-C4D). A single run is possible every 55s (sampling rate=65h-1). The separation by CE-C4D was achieved on a fused silica capillary (50cm length - 10cm effective, 50μm i.d.) with a background electrolyte (BGE) composed by 20mmolL-1 of 2-(morpholin-4-yl)ethane-1-sulfonic acid (MES) and 20mmolL-1 of histidine (HIS) (pH 6.0). Detection limits were estimated at 20 and 30μmolL-1 and recovery values for spiked samples were 98 and 102% for NPZ and Zn, respectively. The developed procedure was compared to HPLC (NPZ) and FAAS (Zn) and no statistically significant differences were observed (95% confidence level).