Studies On The Detection And Environmental Behavior Of Microcystins In Water, Sediment And Cropland

The pollution of microcystins following the breaking out of cyanobacterial bloom has raised more and more concerns. In the present study, the behavior of MC-RR in natural water body, lake sediments and crop soil, and the influence of MC-RR on the growth of crops were investigated. The main results were showed as following:1. The ratio of methanol, water and TFA was regulated to change the polarity and the pH of the rinse solution and the eluent, so as to improve the HPLC detection method for trace MCs in natural water bodies. The results showed that, 40%-45% methanol-water solution containing 0.1% TFA could get good effects on the rinse of impurity,and 70% methanol-water solution containing 0.1% TFA could elute all the MCs in SPE-cartridge(C18).2. During Sep 2001 to Aug 2002, monthly variances of Microcystin-RR (MC -RR), and some environmental parameters were investigated in Lake Dianchi. The concentrations of MC-RR detected by HPLC varied in between 0.65 and 2.44μg/l with an average of 1.43μg/l. The concentration of MC-RR has no direct relationship with the biomass of bloom-forming Microcystis spp. in Lake Dianchi. Though all the factors influencing Microcystis biomass and microcystin (MC) production should have effect on the concentration of MC-RR, after counteract with each other, only water temperature was contained in the linear models of MC-RR concentration during water bloom breaking out period and other seasons, and no linear model could be founded between the concentration of MC-RR and environmental parameters during the sampling period. This study has demonstrated that the relationship between MC-RR concentration and environmental parameters may vary widely depending on the time period selected for study.3. The adsorption and extraction of microcystin-RR (MC-RR) in lake sediments...