Ultrasonic extraction and capillary gas chromatography determination of nicotine in pharmaceutical formulations

A simple, rapid and accurate analytical method was developed for the determination of nicotine in pharmaceutical formulations. The method comprises a fast ultrasonic extraction (UE) with heptane as a solvent followed by direct capillary gas chromatography (GC) separation and quantitation. The application of ultrasound significantly accelerated the analyte extraction. For example, in the conventional method each extraction step takes up to 24 h whereas with the ultrasonic extraction method developed it took less than 20 min to achieve the same extraction efficiency. The ultrasonic extracts were directly chromatographed on an Alltech EC(TM)-5 capillary GC column and a base line separation was achieved within 10 min. The consumption of environmental harmful organic solvent in this developed UE-capillary GC method is much lower than in conventional extraction-HPLC methods. The UE developed uses only 1/6 of organic solvent needed in conventional extraction. The subsequent GC analysis does not consume organic solvent as mobile phase while HPLC does. This green analytical method has been successfully applied to determine the nicotine content in both chewing and transdermal systems. Standard calibration curves were linear over the concentration range 1.00-500.0 mug/mL. Within-day and day-to-day relative standard deviations less than 1.9 and 2.0%, respectively. (C) 2004 Elsevier B.V. All rights reserved.