Optimization of Microcystin Extraction for Their Subsequent Analysis by HPLC-MS/MS Method in Urban Lake Water

Abstract

Abstract-This paper represents to propose an effective extraction procedure for traditional toxin determination techniques in urban lake. Efficiency of each extraction solvent as well as other key parameters affecting extraction efficiency including ultrasonication time and extraction pH were evaluated and optimized. The present study results indicated that 40% acidified methanol (pH~3) with sonication 15~20min has been shown to be a rapid and efficient method for the routine analysis of a wide range of microcystins in water samples. Our study also suggested that analytical method based on HPLC-MS/MS with SPE techniques provides a simplified enrichment procedure and rich information for both quantization and identification effective tool for analysis of urban landscape water quality. The development of this method may facilitate the understanding of the best extraction method for the routine analysis of microcystins in water bodies. Moreover, it may be valuable for purification scale. Index Terms-Microcystin, extraction, HPLC-MS/MS, urban landscape water. I. INTRODUCTIONUrban landscape water in China are very often man-made ecosystem. They are very small and shallow. As an essential part of urban ecosystem, urban lake also play an important role in promoting socio-economic development, by regulating climate and providing a good place for recreational [1]- [2]. With increasing anthropogenic activities and excessive inputs of nitrogen and phosphorus to water environments, urban lake waters quality are extremely deteriorated in recent years. As a consequence, the appearance of Cyanobacteria (blue-green algae) can produce microsytins, frequently breakout in highly eutrophication lakes. It is considered to be an important water quality problem, implicating that a serious health problem in water supplies, both for livestock and human health [3]-[5].Microcystin is the most commonly synthesized toxin produced by toxin producing cyanobacteria species of Currently, there is a lack of understanding toxicology and risk assessment of urban lake Cyanobacterial toxins. For deeply study urban lake microcystins during algal blooms, optimization of extraction were conducted by HPLC-MS/MS approaches in our study for determination of microcystins from urban lake samples. II. MATERIALS AND METHODS A. ChemicalsAll the chemicals include HPLC-S grade acetonitrile, HPLC grade methanol and Trifluoroacetic acid (TFA) were purchased from Beijing Chemicals Ltd. Ultra-pure water was prepared on a Milli-Q Synthesis system (Millipore, France). microcystin LR, RR standards were bought from Beijing express Company. Sep-pak ODS cartridge (1000g, 12ml) was manufactured by Tianjin Alega Technologies. B. Sample Preparation for Microcystins ExtractionBefore the HPLC analyses, all water samples (1 L) were filtered on GF/C filters. Commercially available SPE fibers were purchased from Alega. Each fiber was eluted by 20ml methanol and pure water 20ml separately before extraction. To carry out the SPE extraction, water samples were extracted under diff...