LC-MS analysis with thiol derivatization to differentiate [Dhb7]- from [Mdha7]‑Microcystins: Analysis of cyanobacterial blooms, planktothrix cultures and European crayfish from lake Steinsfjorden, Norway

Miles, C. O.; Sandvik, M.; Haande, S.; Nonga, H. E.; Ballot, A.

dc.creator	Miles, C. O.
dc.creator	Sandvik, M.
dc.creator	Haande, S.
dc.creator	Nonga, H. E.
dc.creator	Ballot, A.
dc.date	2017-06-14T13:03:21Z
dc.date	2017-06-14T13:03:21Z
dc.date	2013-03-26
dc.date.accessioned	2022-10-25T08:50:34Z
dc.date.available	2022-10-25T08:50:34Z
dc.identifier	https://www.suaire.sua.ac.tz/handle/123456789/1591
dc.identifier.uri	http://hdl.handle.net/123456789/90369
dc.description	Environmental Science and Technology 2013, Vol 47: 4080−4087
dc.description	Kinetic studies showed that [Asp3, Dhb7]MC-RR reacted with mercaptoethanol hundreds of times more slowly than MC-RR and a range of other [Mdha7]-containing microcystin congeners. The difference in reaction rate was sufficiently large that derivatization of microcystin-containing samples with mercaptoethanol, followed by LC-MS analysis, clearly discriminated between microcystins containing the isobaric [Dhb7]- and [Mdha7]-groups. Application of this approach, using LC-MS with both-ion trap and triplequadrupole mass spectrometers, to water samples and Planktothrix cultures from Lake Steinsfjorden, Norway, demonstrated the presence of [Asp3, Dhb7]MC-RR (5), [Asp3]MC-RY (14), and [Asp3]MC-LY (16), as well as analogues tentatively identified as [Asp3]MC-RR (4), [Asp3, DMAdda5, Dhb7]MC-LR (6), [Asp3, Dhb7]MC-HtyR (8), [Asp3]MC-HtyR (9), [Asp3, Dhb7]MC-LR (10), [Asp3]MC-LR (11), [Asp3, Dhb7]MC-RY (15), and [Asp3, Dhb7]MC-LY (17), together with low levels of several other analogues. This is the first use of this thiol-based LC-MS approach to identify Dhb-containing microcystins, and allowed identification of LC-MS peaks in a mixture of [Mdha7]- and [Dhb7]-congeners of [Asp3]MC-RR (4, 5), -RY (14, 15), and -LY (16, 17) in the samples from L. Steinsfjorden. This is also the first report of MC-RY-congeners outside of Africa, or in Planktothrix spp. Analysis of European crayfish (Astacus astacus) taken from L. Steinsfjorden revealed the presence of only trace levels of microcystins in the edible parts.
dc.format	application/pdf
dc.language	en
dc.publisher	American Chemical Society
dc.subject	Thiol Derivatization
dc.subject	Cyanobacterial Blooms
dc.subject	Planktothrix Cultures
dc.subject	European Crayfish
dc.subject	Lake Steinsfjorden
dc.title	LC-MS analysis with thiol derivatization to differentiate [Dhb7]- from [Mdha7]‑Microcystins: Analysis of cyanobacterial blooms, planktothrix cultures and European crayfish from lake Steinsfjorden, Norway
dc.type	Article