Speciation of volatile antimony compounds in culture headspace gases of Cryptococcus humicolus using solid phase microextraction and gas chromatography–mass spectrometry

Abstract

Direct analysis of the volatile antimony compounds stibine (SbH 3 ), monomethylantimony, dimethylantimony (Me 2 Sb) and trimethylantimony (Me 3 Sb) using solid phase microextraction (SPME) with polydimethylsiloxane fibres and gas chromatography±mass spectrometry (GC±MS) is described. The best analyte to background signal ratio was achieved using a 20 min extraction time. Antimony species were separated using a 3% phenylmethylsilicone capillary column operated at a column pressure of 70 kPa, a flow rate of 1.4 ml min À1 and temperature ramping from 30 to 36°C at 0.1°C min À1 . Cryogenic focusing of desorbed species was required to achieve resolution of antimony species. The optimized SPME±GC±MS method was applied to the analysis of headspace gases from cultures of Cryptococcus humicolus incubated with inorganic antimony(III) and (V) substrates. The headspace gases from biphasic (aerobic±anaerobic) biomass-concentrated culture incubations revealed the presence of SbH 3 , Me 2 Sb and Me 3 Sb. Stibine was the major antimony species detected in cultures amended with inorganic antimony(V). Me 3 Sb was the sole volatile antimony species detected when cultures were amended with antimony(III).

Microbial Antimony Biogeochemistry: Enzymes, Regulation, and Related Metabolic Pathways

“…In addition, the biovolatilization and bioaccumulation of antimony by S. brevicaulis were recently quantified (83). The aerobic yeast Cryptococcus humicolus was also reported to biomethylate both inorganic Sb(III) and Sb(V) (84). It has been suggested that the toxic gases generated from Sb methylation by the fungus S. brevicaulis in crib mattresses might be a cause for sudden infant death syndrome (SIDS) (85).…”

Investigations into the role of methylcobalamin and glutathione for the methylation of antimony using isotopically enriched antimony(V)

“…15,42 The results of Andrewes et al 1 did not support the biomethylation of antimony in its pentavalent state by the fungus S. brevicaulis, whereas other groups 45,50,53 reported the methylation of an antimony(V) substrate.…”

Review: Biological methylation of less‐studied elements

“…A nonvolatile dimethylantimony compound (possibly dimethylstibinic acid) also formed, 117,120 and methylstibine and dimethylstibine have also been reported. 122 When 13 CD 3 -labeled methionine was incorporated into the growth media of S. brevicaulis, the label was incorporated into the methylantimony products. 120 The fungus Cryptococcus humicolus generated methylantimony compounds from both antimony(III) and antimony(V) substrates; 122 however, stibine was the major product from antimony(V), and trimethylstibine was the exclusive product from antimony(III).…”

“…122 When 13 CD 3 -labeled methionine was incorporated into the growth media of S. brevicaulis, the label was incorporated into the methylantimony products. 120 The fungus Cryptococcus humicolus generated methylantimony compounds from both antimony(III) and antimony(V) substrates; 122 however, stibine was the major product from antimony(V), and trimethylstibine was the exclusive product from antimony(III). In comparative studies, antimony was methylated much less rapidly and less extensively than arsenic.…”