Methods validation and analysis of Spirulina (Arthrospira platensis) microcystin contaminants by Enzyme-Linked Immunosorbent Assay (ELISA)

Abstract

Spirulina (Arthrospira platensis) production dominates the global microalgae market due to its high nutritional value. Spirulina can be cultivated in ponds with quality control due to the possible growth of cyanotoxins like Microcystis sp. that produce microcystins. The Enzyme-Linked Immunosorbent Assay (ELISA) method was used and validated with linearity, precision, reproducibility, and accuracy parameters that met the criteria for microcystin analysis. The regression curve gave the linear regression, the value of the coefficient of correlation (r) 0.99 showed a very strong correlation, and coefficient determination (R2) was 0.988 (R2 > 0.90). The precision analysis in repeatability (RSDanalysis < 2/3RSD Horwitz) and reproducibility (RSDanalysis < RSD Horwitz) showed an acceptable value with a significance value of 0.191 (p-value <0.05) that showed no significance difference. The accuracy from spiking analysis with a recovery percentage of 79.90±17.97% was still within the range of 40% to 120%, with a LOD value of 0.1 µg/kg. Analysis completed on spirulina powder showed that the spirulina product has a good quality with microcystin levels of 1.39 ± 0.16 µg/kg (dry basis), 719 times below the predetermined limit of 1000 µg/kg based on the Oregon Health Division Regulation for blue-green algae (BGA).