GC-MS Determination of Nicotine in Gum Chewing Tobacco

5 pellets of the sample of (1.42±0.01) g were dissolved with 8 mL of 5 mol·L^-1 sodium hydroxide solution and 40 mL of hexane containing internal standard substance. The solution was magnetically stirred for 110 min, and stood for 20 min. An aliquot of 2 mL of the extract from the upper layer was dried with anhydrous sodium sulfate, and filtered through organic filter membrane of 0.22 μm. The sample solution was separated by GC using DB-5MS chromatographic column. SIM was adopted in MS analysis. Linearity range of nicotine was 4.00-200 mg·L^-1, with detection limit (3s) of 0.19 mg·L^-1. Test for recovery was made by standard addition method, giving results in the range of 91.0%-96.1%, with RSDs (n=6) all less than 3.0%.