Development and application of ultra performance liquid chromatography-electrospray ionization tandem triple quadrupole mass spectrometry for determination of seven microcystins in water samples.

In the present work, an ultra performance liquid chromatography (UPLC)-electrospray ionization tandem triple quadrupole/mass spectrometry (ESI-MS/MS) method was developed in selected reaction monitoring (SRM) mode to determine the amounts of seven/microcystin variants (MCYST-RR, -YR, -LR, -LA, -LY, -LW, -LF) in water samples. Solid phase extraction (SPE) or porous filter was used for sample cleaning-up and analyte enrichment. A C18 column enabled separation of 7 microcystins within 10min. Translation reaction ions including 995.6>134.9 (RR), 1045.8>135.1 (YR), 910.9>375.7 (LA), 1002.3>375.6 (LY), 520.1>135.0 (LR), 1025.8>891.7 (LW), 986.8>852.6 (LF) were set as quantitative ions and the enkephalin was the internal standard. Upon method validation, the limits of detection (LODs) and limits of quantification (LOQs) were found to be 0.06microgL(-1) and 0.2microgL(-1) (injection volume of 10microL), respectively, for all seven microcystin variants. The correlation coefficients were larger than 0.994 in all linear ranges and recoveries were in the range of 66.24-99.22%. The developed approach was highly sensitive and easy to perform. It generated accurate quantitative results for the analysis of microcystins in environmental water samples with a wide concentration range. The results showed that MC-RR and MC-LR widely existed in polluted water, while MC-LA and MC-LY were detected sporadically.