Variability of Microcystin-LR Standards Available from Seven Commercial Vendors

Compares quantity, purity, and toxicity of MCLR standards from available vendors.

Impact/Purpose

Cyanotoxin standards that are not sold as certified reference materials varied from the vendor's label mass by 33 to 106% in this study. Water managers using these standards for quantitating and reporting cyanotoxin levels in drinking and recreational water and researchers using these standards for toxicology studies could have inaccurate results if the standards are not checked for purity and quantity by LC-MS/MS first. Ready access to experienced chemists with this capability can be difficult to access. This study compared the quantity and purity of the standards and toxicity in mice of microcystin-LR standards from seven vendors. The toxicity response in the mice closely mirrored the actual quantity of the toxin in the standards to demonstrate that using the mass on the label for a single dose can vary from non-toxic to lethal effects. The purpose of this study is to highlight the variation of mass in microcystin and likely other natural toxin standards sold to the scientific community for research and reporting. Based on our findings, we recommend an industry-wide policy for improving purity and providing accurate label quantity of toxin standards. 

Citation

Lang, J., D. Jenkins-Hill, N. Chernoff, J. Schmid, M. Strynar, J. McCord, C. Rosal, AND T. Thanh. Variability of Microcystin-LR Standards Available from Seven Commercial Vendors. MDPI, Basel, SWITZERLAND, 14(10):705, (2022). [DOI: 10.3390/toxins14100705]

DOI: Variability of Microcystin-LR Standards Available from Seven Commercial Vendors