Arsenic Speciation Analysis of Cultivated White Button Mushrooms (Agaricus bisporus) Using High-Performance Liquid Chromatography−Inductively Coupled Plasma Mass Spectrometry, and X-ray Absorption Spectroscopy

Abstract

Agaricus bisporus mushrooms were grown in compost amended with either arsenic-contaminated mine waste or an arsenate solution, to a final concentration of approximately 200 µg‚g -1 . Fungi were cultivated at a smallscale mushroom facility in Vineland (ON), where the controlled environment allowed for a large number of fruiting bodies (mushrooms) to be produced. The total arsenic concentrations as well as speciation were examined for each treatment over several harvests (breaks). Total concentrations were determined by acid digestion and inductively coupled plasma mass spectrometry (ICP-MS) detection and ranged from 2.3 to 16 µg‚g -1 dry mass in treatment mushrooms. Arsenic compounds were extracted from mushrooms with methanol/water (1:1 v/v), and separated by high-performance liquid chromatography (HPLC, anion/cation exchange) before detection with ICP-MS. Fruiting bodies from all treatments contained arsenite, dimethylarsinic acid (DMA), and arsenobetaine (AB), and to a lesser extent arsenate and trimethylarsine oxide (TMAO). The ratio of arsenic compounds did not vary greatly over the first three harvests. AB was absent in compost not inoculated with A. bisporus supporting the hypothesis that AB is a product of fungal, not microbial, arsenic metabolism. X-ray absorption spectroscopy results lead us to hypothesize that AB plays a role in nutrient translocation within the fruiting body, as well as maintaining turgor pressure to ensure the mushroom cap remains elevated for maximum spore dispersal.

Total contents of arsenic and associated health risks in edible mushrooms, mushroom supplements and growth substrates from Galicia (NW Spain)

“…Mushrooms provide relatively high concentrations of essential elements but are able to accumulate different toxic metals (e.g., Pb, Hg, Cd) and metalloids like arsenic (As), which could represent a serious risk to consumer health. Mushrooms may play an important role in As cycling in the environment, both as decomposers and plant symbioses (Smith et al, 2007). Therefore, intensive research has been carried out to detect and explain the presence and distribution of many heavy metals in edible mushrooms (Alonso et al, 2000;Cocchi et al, 2006;García et al, 2013;Gonzálvez et al, 2009;Li et al, 2011;Melgar et al, 2009;Soeroes et al, 2005;Ouzouni et al, 2009).…”

“…Determining the form of arsenic for mushrooms grown in unpolluted and polluted soils is an important issue for understanding the uptake, transfer, and accumulation processes in fruiting bodies. For this reason, analysis of arsenic species in selected mushroom species was performed in some earlier studies (Niedzielski et al, 2013;Smith et al, 2007).Accordingly, accurate data on As content in foods are essential both in primary research and subsequent governance and legislation that allows the assessment of health risks to be carried out.…”

Arsenic in the human food chain, biotransformation and toxicology – Review focusing on seafood arsenic

“…Fresh-water organisms also contain AB, but at much lower levels (< 0.1 mg As/kg dw) [10]. AB has been detected in some terrestrial foods, like mushrooms [33] and poultry, in the latter possibly originating from seafood in the feed or added as a growth promoter [34,35].…”

The sensitive, anion-selective detection of arsenate with poly(allylamine hydrochloride) by single particle plasmon-based spectroscopy

“…Because of this, numerous methods for its detection have been developed. Spectroscopic techniques including atomic absorption spectroscopy (AAS) [4], inductively coupled plasma-mass spectroscopy (ICP-MS) [5][6][7], atomic fluorescence spectroscopy (AFS) [8], and chromatographic techniques such as liquid chromatography [9] and ion chromatography [10] are currently in widespread use for the detection of arsenate compounds. However, spectral and chemical interference is a significant weakness in these established techniques, and considerable efforts have been made to overcome these limitations.…”