Monitoring of microcystin-LR concentration in water reservoir

摘要

Microcystins (MCs) are a group of cyanotoxins with hepatotoxic effects and can induce liver cancer. Among them, microcystin-LR (MC-LR) is the most toxic with 1 mu g/L guideline value for potable waters. Therefore, it is very important to develop analytical methods for the detection and monitoring of MC-LR concentrations in raw water sources for public health protection. For this purpose, water samples were taken from a dam in south of Iran in a period of 2 years. MC-LR was extracted from samples by solid-phase extraction method using a C-18 cartridge and then measured by reverse phase high performance liquid chromatography after calibration by standard solutions. Total phosphorous concentration and water temperature were measured for determination of environmental conditions in each season. Maximal and minimal concentrations of MC-LR were observed in early autumn (6.2 mu g/L) and late winter (0.4 mu g/L), respectively. MC-LR existed at all times in water source because of its resistance to natural physiochemical degradation and biodegradation. Thus, raw water source management is necessary to prevent MC-LR secretion for public health protection.