Determination of microcystins and nodularin (cyanobacterial toxins) in water by LC–MS/MS. Monitoring of Lake Marathonas, a water reservoir of Athens, Greece

• Published in: Journal of hazardous materials 2013-12, Vol.263, p.105-115
• Main Authors: Kaloudis, Triantafyllos, Zervou, Sevasti-Kiriaki, Tsimeli, Katerina, Triantis, Theodoros M., Fotiou, Theodora, Hiskia, Anastasia
• Format: Article
• Language: English
• Subjects: Chromatography, Liquid; Environmental Monitoring; Greece; Lake Marathonas; Lakes - analysis; LC–ESI-MS/MS; Microcystins; Microcystins - analysis; Nodularin; Peptides, Cyclic - analysis; PPIA; Tandem Mass Spectrometry; Water Pollutants, Chemical - analysis; Water Supply - analysis
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2013.07.036

•Method for the determination of MCs and NOD in water by SPE and LC–ESI-MS/MS.•New patterns of MC-LA fragmentation have been observed.•Method validation by assessment of specificity, linearity, accuracy and precision.•MCs monitoring in Lake Marathonas (July 07–December 10).•MC-LR, MC-RR and MC-YR were detected. A method for the determination of the hepatotoxic cyanotoxins microcystins (MCs, i.e. MC-LR, MC-RR, MC-YR, MC-LA) and nodularin (NOD) in water was developed using liquid chromatography with electrospray ionization triple quadrupole mass spectrometry (LC–ESI-MS/MS) after solid phase extraction (SPE). New patterns of fragmentation of MC-LA were observed under the experimental conditions used. The method was fully validated to meet accreditation criteria. Mean recoveries at three concentration levels (0.006, 0.1 and 1μgL−1) ranged between 70 and 114% with %RSD values generally below 20%. Detection limits were 2ngL−1 for all hepatotoxins. The method was applied to study the occurrence of MCs and NOD in Lake Marathonas, a water reservoir of Athens, over a period from July 2007 to December 2010. The protein phosphatase inhibition assay (PPIA) was additionally used for fast screening of samples. MC-YR, MC-LR and MC-RR were detected and found to vary seasonally with consistent peaks during early autumn, having maximum concentrations of 717, 451 and 174ngL−1, respectively. The results of this study constitute the first report on the presence, concentration levels and seasonal variations of MCs in Lake Marathonas. None of the target cyanotoxins were detected in treated drinking water samples during the period of the study.