ABSTRACT
A method has been developed by solid phase extraction-high performance liquid chromatography coupled with photodiode array detector for simultaneous determination of 10 kinds of cyanotoxins in lake water, including microcystin-RR (MC-RR), MC-YR, MC-HtyR, MC-LR, MC-WR, MC-LA, MC-LY, MC-LW, MC-LF and nodularin ( NOD ).The samples were enriched and purified by a HLB solid phase extraction column.The separation was performed on a Waters C18 column (250 mm×4.6 mm, 5 μm) with the gradient elution of acetonitrile and water containing 0.05% trifluoroacetic acid.The flow rate of the mobile phase was 0.8 mL/min.The column temperature was 30℃ and the injection volume was 20 μL.The photodiode array detector was scanned from 190 nm to 300 nm and the detection wavelength was 238 nm.Multiple qualitative analyses were completed according to retention time, full scanning spectrum of photodiode array detector and purity analysis of chromatographic peak.Good linearity was observed in the cyanotoxin concentration range of 0.05 mg/L-2.0 mg/L with correlation coefficients ( R) from 0.9998 to 0.9999.The limits of detection for 10 cyanotoxins were in the range of 0.005 μg/L-0.020 μg/L.The recoveries were in the range of 85.1%-105.3% at the three spiked levels of 0.1 mg/L, 1.0 mg/L and 1.8 mg/L with the relative standard deviations ( RSD ) of 0.8% -9.2%.The method was characteriZed by wide applicability, convenient operation, quick analytical rate, high sensitivity, good accuracy and high recovery.The qualitative accuracy was improved by using multiple qualitative analyses.This method was successfully applied to determination of 10 kinds of cyanotoxins in lake water.