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Method Development and Monitoring of Cyanotoxins in Water (ACS Central Presentation)
Citation:
Shoemaker, J., Dan Tettenhorst, W. Dietrich, A. Delacruz, AND Joel Allen. Method Development and Monitoring of Cyanotoxins in Water (ACS Central Presentation). ACS Central Regional Meeting, Covington, KY, May 18 - 21, 2016.
Impact/Purpose:
This research provides a standardized ambient water method for cyanotoxins that can be used in future water quality criteria regulations.
Description:
Increasing occurrence of cyanobacterial harmful algal blooms (HABs) in ambient waters has become a worldwide concern. Numerous cyanotoxins can be produced during HAB events which are toxic to animals and humans. Validated standardized methods that are rugged, selective and sensitive are needed for these cyanotoxins in drinking and ambient waters. EPA Drinking Water Methods 544 (six microcystins [MCs] and nodularin) and 545 (cylindrospermopsin [CYL] and anatoxin-a [ANA]) have been developed using liquid chromatography/tandem mass spectrometry (LC/MS/MS). This presentation will describe the adaptation of Methods 544 and 545 to ambient waters and application of these ambient water methods to seven bodies of water across the country with visible cyanobacterial blooms.Several changes were made to Method 544 to accommodate the increased complexity of ambient water. The major changes were to reduce the sample volume from 500 to 100 mL for ambient water analyses and to incorporate seven additional MCs in an effort to capture data for more MC congeners in ambient waters. The major change to Method 545 for ambient water analyses was the addition of secondary ion transitions for each of the target analytes for confirmation purposes. Both methods have been ruggedly tested in bloom samples from multiple bodies of water, some with multiple sample locations and sampling days. For ambient water bloom samples spiked with MCs (>800 congener measurements), 97% of the measurements met quality control (QC) criteria of ±50%. For CYL and ANA, >99% of the 334 measurements met QC criteria of ±30%. Minimum reporting levels were established at 0.017-0.30 µg/L in ambient water samples for MCs, 0.30 µg/L for CYL, and 0.12 µg/L for ANA. Cyanotoxin profiles, QC results and correlations of enzyme linked immunosorbent assays vs LC/MS/MS analyses in the various water bodies will be presented.
