抄録
A study on the extraction method of plasma nicotine and cotinine for FTD gas chromatography is described. Ether anhydrous for nicotine and chloroform for cotinine are suitable organic solvent, respectively. A internal standard method using quinoline or 5-aminoquinoline is profitable to obtain a good result. Two kinds of extraction method were adopted, which were the method l for single determination of nicotine and the method II for simulataneous determination of nicotine and cotinine. Reproduciblility of the methods was good and the recovery of nicotine and cotinine was approximately 90-100% of added ones to plasma. The method was sufficiently sensitive to detect nicotine of 0.1ng·ml-1and cotinine of0.2ng·ml-1.
The concentration of nicotine in plasma of 10 non-smokers was2.5±2.93ng·ml-1 and cotinine could not be detected. Plasma nicotine and cotinine concentration of 20 smokers before smoking were14.5±8.68ng·ml-1and145.3±138.23ng·ml-1respectively. Reagent blank value in these methods was about2-3ng·ml-1as nicotine and none as cotinine, it may be due to contaminations in reagent and during the procedure. Plasma nicotine rised to maximum value at just behind or 15minutes after voluntary smoking of one cigarette and falled to the former value after 1hour. In case of plasma cotinine, its rise and fall was more gradual in comparison with nicotine and the retention-time in plasma was longer than nicotine consequently.
