Abstract: Effective solid phase extraction (SPE) ex-treatment method and sensitive enzyme-linked immunosorbent asssay (ELISA) were developed for determining the nodularins(NOD) and cylindrospermopsins(CYN) in water samples. Due to the different polarities, two different ex-treatment methods were applied to NOD and CYN, respectively. The methods were developed as followed: ① For NOD,firstly the C₁₈ column was activated by 10 mL methanol and 10 mL Milli-Q water; then the sample was applied to the column at 3-4 mL/min; after washing the column with 10 mL water, the NOD was eluted with 10 mL methanol; then the eluent was dried up with a rotary evaporator, and lastly the final volume was fixed to 1 mL with Milli-Q water for ELISA analyse. ② For CYN, the carb SPE tubes were activated with 10mL methanol and 10mL Milli-Q water; then the sample was applied to the tubes at 2-3 mL/min; after washing the tubes with 10mL methanol, the CYN was eluted with 12 mL methanol containing 0.1% trifluoroacetic acid;then the eluent was dried up with a rotary evaporator, lastly the final volume was fixed to 1 mL with Milli-Q water containing 0.1% ammonia for ELISA analyse. The results indicated that these methods can guarantee the good recoveries of NOD and CYN for ELISA analyse, which could reach to 94.3% and 77%, respectively.

Key words: nodularins, cylindrospermopsins, ELISAs