Multielemental Speciation Analysis of Fungi Porcini (Boletus edulis) Mushroom by Size Exclusion Liquid Chromatography with Sequential On-line UV-ICP-MS Detection

Abstract

An analytical methodology to determine the molecular weight (MW) distribution patterns of several elements among different compounds present in commonly consumed edible mushrooms is presented in this work. A hyphenated technique based on size exclusion liquid chromatography (SEC) coupled on-line to UV and inductively coupled plasma mass spectrometry (ICP-MS) detection was used. The association of the elements to high and low MW fractions was confirmed with sequential detection by UV and ICP-MS. Separation of the fractions was performed by injecting a 100 microL sample volume to a Superdex 75 column. The effect of different mobile phases on the separation was evaluated. Additionally, three different extraction conditions including 0.05 mol L(-1) NaOH, 0.05 mol L(-1) HCl, and hot water at 60 degrees C were applied to extract the elemental species from the mushroom samples. Significant differences were observed in the chromatograms depending on the extraction conditions utilized. Optimization of the experimental variables involved in the SEC-UV-ICP-MS coupling was carried out. The method was applied to investigate the fractionation patterns of Bi, Co, Cu, Fe, I, Mo, Ni, Se, and Zn in fungi porcini (Boletus edulis) mushroom. The results obtained in this work indicate an important association of most of the elements to high MW fractions.

Selenium contents of Portuguese commercial and wild edible mushrooms

“…However, other Boletaceae mushrooms, from the genus Boletus (B. fragans and B. spretus) and X. subtomentosus, (less appreciated and consumed), have lower contents of selenium, although the values were higher than those observed in species of other fungal families studied (Table 2 and Table 3). The selenium contents of B. edulis, B. pinophilus and B. aereus are in agreement with the reported values of selenium content for these mushrooms from other countries (B. edulis 4.1-63 mg/kg DW, Piepponen et al, 1983;Stijve, 1977;Mutanen, 1986;Michellot et al, 1998;Wuilloud, Kannamkulmarath, & Caruso, 2004;Cocchi et al, 2006;Falandysz, 2008;B. pinophilus 27-55 mg /kg DW;Falandysz, 2008;B.…”

The trace element content of top-soil and wild edible mushroom samples collected in Tuscany, Italy

“…Though it is not precisely known if and when uptake or accumulation in fruiting bodies occur by specific, selective binding or not, single or multiple element chelating proteins or agents have been reported in higher fungi (Schmitt and Meisch 1985;Collin-Hansen et al 2007;Chudzyński and Falandysz 2008). Gene polymorphisms (Palapala et al 2002), gene expression, and levels of proteins physiologically related to soil metal absorption, extrusion, transport, metabolism, or accumulation/compartmentalization inside fruit bodies can be considered adaptive signals and responses to environment/soil composition, as in part observed for mycorrhizal species (Bellion et al 2007); some authors have also evidenced that, in B. edulis, different metals undergo a different speciation (Wuilloud et al 2004). Beside being a mirror of mushroom genetic variance/adaptation, high-(e.g., metalloproteins, phytochelatins, phosphoglycoproteins) or low-(e.g., methylmercury or selenocystheines/selenomethionine, arsenate) molecular weight metal species inside fruit bodies could, at the same time, be better predictors of the degree of oligo-element toxicity or nutritional impact for consumers than trace element absolute concentrations (Kalač 2010).…”

Selenium in agriculture, food, and nutrition

“…In extracts from mushroom samples (B. edulis from Ohio), Se was primarily associated with a fraction between 2.9-3.2 kDa and a low-molecular-weight fraction. Additionally, about 10 % of Se in the NaOH extraction was found associated with a fraction at 50 kDa 10.5 % [145].…”