J. Feldmann et Wr. Cullen, OCCURRENCE OF VOLATILE TRANSITION-METAL COMPOUNDS IN LANDFILL GAS - SYNTHESIS OF MOLYBDENUM AND TUNGSTEN CARBONYLS IN THE ENVIRONMENT, Environmental science & technology, 31(7), 1997, pp. 2125-2129
Evidence for the occurrence of volatile molybdenum and tungsten compou
nds in the environment is presented for the first time. The gases from
three different municipal waste deposits were sampled and analyzed fo
r volatile metal and metalloid compounds by using gas chromatography c
oupled with inductively-coupled plasma mass spectrometry (GC-ICP-MS).
In addition to the known hydrides and methylated compounds of As, Se,
Sn, Sb, Te, Hg, Pb and Bi, volatile Mo and W compounds were found in c
oncentrations of about 0.2-0.3 mu g of Mo/m(3) and 0.005-0.01 mu g of
W/m(3). The isotopic fingerprint of the detected Mo and W from the sam
ples matched perfectly with Mo and W standards. The correspondence of
the samples' retention times (GC-ICP-MS) with those of standards provi
des convincing evidence that Mo(CO)(6) and W(CO)(6) are present in lan
dfill gas. The toxicity and origin of these compounds are discussed.