Quantitation of Microcystins and Nodularin in Drinking Water Samples to Meet EPA Method 544 Requirements Using QSight LC/MS/MS

Drinking Water
Poster Presentation

Prepared by J. Jalali1, V. CAI2
1 - PERKINELMER, 2122 Marshallfield Ln Redondo beach CA 90278, Redondo Beach, CA, 90278, United States
2 - PERKINELMER, , , United States


Contact Information: [email protected]; 424-350-8175

ABSTRACT

Cyanobacteria, also known as blue green algae, can produce cyanotoxins known as microcystins and nodularins. Cyanobacteria are found in surface waters such as lakes, streams, and ponds and when conditions are favorable, cyanobacteria can bloom and release cyanotoxins into the water. Cyanotoxins often exist intracellularly in cyanobacteria and are released into the water when cells die. Blooms caused by cyanobacteria can be harmful to the human health, animals, and the environment. Microcystin-LR (MC-LR) is one of the most common cyanotoxins and ingestion will cause negative human health effects such as liver inflammation and hemorrhage, vomiting and diarrhea, and abdominal pain. There are both non-toxic and toxic versions of cyanobacteria and it is impossible to tell if a species of cyanobacteria is toxic or non-toxic by its appearance. The US EPA has a health advisory for a maximum level of microcystins as 0.3 μg/L for infants and young children and 1.6 μg/L for school-aged children and adults. The World Health Organization recommends microcystin levels be kept below 1 μg/L in drinking water. Molecular tests are available to determine if cyanobacteria carry the toxin gene but quantitative analysis, such as liquid chromatography tandem mass spectrometry (LC/MS/MS), is required to determine if cyanobacteria are producing cyanotoxins. EPA Method 544 uses solid phase extraction (SPE) LC/MS/MS for quantitation of six intracellular and extracellular microcystins and nodularin in 500 mL drinking water samples. In this study, we show that the PerkinElmer QSight® LX50 ultra high-performance liquid chromatography (UHPLC) system coupled with the PerkinElmer QSight® 200 series triple quadrupole mass spectrometer can analyze the six microcystins and nodularin (microcystin-LA, microcystin-LF, microcystin-LR, microcystin-LY, microcystin-RR, microcystin-YR, nodularin-R) as outlined in EPA method 544 with good detection limits from 16 ng/L to 80 ng/L