Application of HPLC and HPCE to the analysis of cyanobacterial toxins

Abstract

SummaryHigh-performance liquid chromatography (HPLC) and different high-performance capillary electrophoresis (HPCE) methods have been developed for the detection and quantitation of cyanobacterial toxins in environmental samples.Cyanobacteria, also known as blue-green algae, are responsible for toxic contamination of fresh water. Several serious episodes involving microcystins have been reported in recent years; the most common and toxic of these hepatotoxins is microcystin-LR (MC-LR). Sensitive analytical methodologies are required for determination of these compounds because of the implications for human health when the toxins are present in drinking water.Different modes of operation of HPCE were used and the results obtained were compared with those obtained by HPLC. Citrate buffer resulted in good separation of the microcystins when capillary electrophoresis was used in capillary zone electrophoresis (CZE) and capillary isotachophoresis (CITP) modes; borate buffer containing sodium dodecyl sulphonate (SDS) was used in micellar electrokinetic chromatography (MEKC). Conditions were optimized and the methods were applied to water samples and cyanobacterial cells containing microcystins. Results obtained by use of HPLC-UV and different modes of operation of CE-UV were compared in terms of sensitivi~,, selectivi~,, and efficiency.

Cyanobacteria and microcystins occurrence in the Guadiana River (SW Spain)

“…SPE has been widely used for extraction and preconcentration procedures, resulting in poor selectivity for trace analysis. Recently, IAC have been developed for these applications, showing clear advantages for sample preparation [38]. In this work the application of both techniques for clean-up purposes was effective in isolating MCs from water samples (figures 2 and 3).…”

“…The raw extracts were cleaned up using conventional solid-phase extraction (SPE) and immunoaffinity SPE procedures (IAC SPE). Conventional SPE was carried out following the conditions described by Aguete et al [38]. After conditioning a C 18 cartridge (Sep-Pak Õ PLUS C 18 cartridges, 1 g, Waters Corporation, Milford, USA) with methanol containing 0.1% trifluoroacetic acid (TFA) (5 mL), methanol (5 mL) and water (5 mL), the extract (200-500 mL) was transferred to the cartridge.…”

“…IAC SPE was performed using immunoaffinity cartridges (ImmunoSep TM , ImmunoKem Ltd., Canada) according to the conditions described by Lawrence and Menard [39], and Aguete et al [38]. Cartridges were conditioned with water (3 mL) and 3 mL PBS prior to loading the sample (200 mL).…”

“…HPLC-UV analysis were performed according to the method described by Aguete et al [37], using an LC-9012 pump, and a 9050 UV-Visible spectrophotometric detector (all from Varian, Walnut Creek, USA). Chromatographic data were processed with Star Chromatography Workstation software (version 4. frequent cyanobacterial species in the Guadiana River were M. aeruginosa, Oscillatoria spp., and some species of Aphanizomenon (Aph.…”

“…Different methods have been applied for the analysis of MCs including inhibition of protein phosphatases 1 and 2A [32,33], ELISA immunoassay, based on molecular recognition by certain antibodies which have good cross-reactivity with microcystin-LR (MC-LR), microcystin-RR and microcystin-YR, but less reactivity with variants microcystin-LY and microcystin-LA [3,24,34], high-performance liquid chromatography (HPLC) with UV or mass spectrometric detection (MS) [35,36] and high-performance capillary electrophoresis (HPCE) [37,38]. Each of these methods provides different information on the MCs content of unknown samples.…”