Advances in solid phase extraction of the cyanobacterial toxin cylindrospermopsin

Abstract

Unlike other cyanotoxins, cylindrospermopsin (CYN) is often found in high concentrations in the extracellular fraction, possibly due to a higher release from the producing cells and a limited degradation once liberated. This fact demands effective recovery methods from environmental samples to guarantee a proper quantification. A reliable and simple solid phase extraction (SPE) method was obtained by the sole use of graphitized carbon cartridges and by paying special attention to both the selection of the most suitable solvent and the need of sample preparation prior to SPE. An acidified combination of dichloromethane and methanol not only showed best recoveries, but also allowed drastic reduction to the elution volumes needed with complete recovery being achieved in only 8 mL. Acidification of the sample and addition of sodium chloride are suggested as valuable improvements to the SPE method and turn out to be essential for correct and robust recovery of CYN in environmental samples of great diversity in terms of pH, DOC, and conductivity. Excellent behavior of the proposed method over a wide range of CYN loadings, applied sample volumes, and DOC loadings was also confirmed.

Cylindrospermopsin production and release by the potentially invasive cyanobacterium Aphanizomenon ovalisporum under temperature and light gradients

“…In the case of the light-intensity experiments, the samples were pre-concentrated by solid-phase extraction according to Wö rmer et al (2009), and the eluted solution was filtered through 0.45 mm pore-size nylon filters (Teknokroma, Spain) and placed in chromatography vials. For the temperature experiments, the filtrate was directly filtered through 0.45 mm pore-size nylon filters and placed in chromatography vials without any other preparation.…”

Sporadic Distribution and Distinctive Variations of Cylindrospermopsin Genes in Cyanobacterial Strains and Environmental Samples from Chinese Freshwater Bodies

“…A total of 2-ml supernatants were collected after the extraction step was repeated. The supernatants were further subjected to solid-phase extraction (SPE) as described previously (61). Carbograph SPE cartridges (6.0 ml, 250 mg) were pretreated with 10 ml of elution solvent (dichloromethane-methanol, 1:4 [vol/vol]) acidified with 5% formic acid (vol/vol) and washed with 10 ml of water.…”

Phylogeography of Cylindrospermopsin and Paralytic Shellfish Toxin-Producing Nostocales Cyanobacteria from Mediterranean Europe (Spain)

“…MCs (variants MC-LR, MC-RR, and MC-YR) were extracted into 90% (vol/vol) methanol and analyzed by ESI LC-MS/MS (51). CYN from the filters was extracted with Milli-Q water (52), and dissolved CYN was solid-phase extracted (53). Both fractions were quantified by ESI LC-MS/MS as described previously (52).…”