Immunoaffinity purification method for detection and quantification of microcystins in lake water

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Toxicology

Background:

• Microcystins are potent cyanotoxins posing risks to aquatic ecosystems and human health.
• Conventional methods for microcystin analysis can be time-consuming and lack efficiency in complex matrices like lake water.

Purpose of the Study:

• To develop and validate a new, efficient clean-up method for microcystin extraction and concentration from lake water.
• To improve the sensitivity and reduce the analysis time for microcystin detection.

Main Methods:

• Solid-phase extraction using Sep-Pak PS-2 or Excelpak SPE-GLF cartridges.
• Immunoaffinity purification utilizing anti-microcystin-LR monoclonal antibodies.
• Quantification via High-Performance Liquid Chromatography (HPLC).

Main Results:

• The method demonstrated high recoveries (85.5-92.2%) for microcystins RR, YR, and LR from spiked lake water.
• Low coefficients of variation (3.3-7.6%) indicate method precision.
• The entire procedure, including extraction, purification, and quantification, required only 3 hours.
• Detection limits for microcystins in lake water were as low as 0.005 µg/l.
• Applied to real-world samples, the method detected total microcystins ranging from 0.012-0.177 µg/l in bloom-affected lakes.

Conclusions:

• The developed clean-up method effectively removes interfering substances and concentrates microcystins from lake water.
• This rapid and sensitive method is suitable for monitoring microcystin contamination in aquatic environments, particularly during harmful algal blooms.