Development of Fabric Phase Sorptive Extraction as an Effective Means of Recovering Microcystins

Microcystis aeruginosa is a species of freshwater cyanobacteria that can be found world-wide. These cyanobacteria are able to multiply rapidly under favorable conditions leading to what is known as an algal bloom. Blooms can be incredibly harmful both ecologically and economically due in part to the potent toxins produced by these microorganisms. M. aeruginosa produces a suite of heptapeptide hepatotoxins, known as the microcystins, which cause sever liver damage when ingested. These toxins are especially difficult to deal with as they are resilient to both hydrolysis and oxidation under normal conditions. The World Health Organization (WHO) has established a safe drinking water limit for microcystins of 1 ppb. In 2014, the municipal water supply in Toledo, Ohio was shut down for three days when microcystin levels exceeded this regulatory limit as a result of an ongoing bloom in Lake Erie. Many local governments that experience these algal blooms are seeking cost-effective ways to concentrate and preserver environmental water samples. One such method is Fabric Phase Sorptive Extraction (FPSE) which provides an economical, simple, and environmentally friendly method for extracting these toxins minimal sample preparation. FPSE allows for the selection of specialized fabrics that can extract and concentrate analytes from aqueous samples. This extraction process is performed by submerging the fabric in a solution containing the analyte for a specified period of time, after which the fabric can be dried and back extracted with an organic solvent to recover the analyte. The protocol for utilizing these fabrics to extract microcystin-RR (MC-RR) is being refined in order to achieve the best possible recovery. Several different fabric chemistries have been tested as well as the optimal temperature, time, and elution solvent needed for the extraction and recovery of MC-RR. At this stage, this extraction method is able to extract MC-RR quantitatively at levels as low as 0.5 ppb and up to 50 ppb. FPSE has incredible potential for concentrating MC-RR and as such could be utilized to further study algal blooms and mitigate the damage caused by these events by concentrating samples which allows for less sensitive detection methods to be used