With the purpose of selecting nicotine as an insecticide applicable to waterculture, we have developed a microanalytical method to examine the nicotine in biological samples, and used the method to carry out experiments on its intake and excretion by fish in an investigation on environmental pollution. In this method, a biological sample is subjected to an alkali decomposition, and the nicotine contained is then extracted from a head-space with an SPME fiber to be determined by GC/MS-SIM. This method is superior to the conventional method in sensitivity, manageability, and selectivity. It also requires low analytical costs, and is friendly to the environment.
In the intake and excretion of nicotine by crucian carps, nicotine was excreted so quickly due to its high water solubility that the original concentration was recovered in 3 days. This result suggests that the use of nicotine in horseradish water culture will have less effect on aquatic creatures than the use of concentratable or persistant pesticides. With respect to the environmental pollution, cultured fish and river fish were found to contain nicotine, with high frequency, in 40 ng/g at the highest, which indicates the possibility of river water being polluted with nicotine.