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(ster'ān, stēr'ān),
The hypothetic parent molecule for any steroid hormone; a saturated hydrocarbon compound that contains no oxygen. The name was originally conceived to achieve forms of systematic nomenclature, but is now supplanted by the fundamental variants: gonane, estrane, androstane, norandrostane (etiane), cholane, cholestane, ergostane, pregnane, and stigmastane.
See also: steroids.
References in periodicals archive ?
Biomarkers such as hopanes and steranes have received some attention, due to their usefulness as indicators of organic matter type and quality, depositional conditions (e.g.
Hydrocarbons, such as n-alkanes, hopanes, and steranes, are also important for investigating contamination by crude oil and its derivatives in recent sediments [10, 11].
5a-b) is attributed to terrestrial organic matter (Simoneit et al, 1986), while plots of [C.sub.27] [C.sub.28] and [C.sub.29] monoaromatic steranes (Fig.
The relative content of [C.sub.27]-, [C.sub.28]-, and [C.sub.29]- regular steranes can indicate the original organic matter inputs of source rocks [20].
The [C.sub.23]-[C.sub.26] to [C.sub.28]-[C.sub.29] tricyclic terpanes and terpane to sterane ratios in the oil shale samples from the Biluocuo region and the oil-bearing samples from the paleo-oil reservoir are low (Fig.
However, sample 10-VI-16 source rock has a [delta][sup.13]C value of -28.1[per thousand] close to source rocks in the Bazhong-Dazhou depression and shows that [C.sub.27]-[C.sub.29] steranes were dominated by [C.sub.27] sterane and [C.sub.27]-[C.sub.29] sterane/[C.sub.29]-[C.sub.33] hopane ratio (of 0.85) higher than other samples (<0.65) from well 10-VI with heavier [[delta].sup.3]C values (Table 3).
In this study, the maturity of oils and reservoir extracts only has a slight variation according to the two sterane parameters, that is, [C.sub.29] 20S/(20S + 20R) and Sterane [C.sub.29][beta][beta]/([alpha][alpha] + [beta][beta]) (Table 3).
The majority of the samples are characterised by the dominance of [C.sub.29] followed by [C.sub.28] regular sterane, or in some samples (D11, D16) by [C.sub.27] regular sterane.
Key words: diesel exhaust, gasoline exhaust, hopane, mutagenicity, PAHs, particulate matter health effects, principal component analysis, semivolatile organic carbon, sterane, toxicity of motor vehicle emissions.
For [C.sub.29] steranes the isomerization ratios S/(S + R) and [alpha][beta][beta]/([alpha][alpha][alpha] + [alpha][beta][beta]) are the two most commonly used sterane maturity parameters.
Following Rock-Eval, TOC analysis, gas chromatographic (GC) (bulk extract) and gas chromatographic-mass spectrometric (GC-MS) (saturated hydrocarbons sterane and terpane) analyses of extracts obtained from three samples (37-9, 52-12, 53-9) were conducted.
The compounds mainly fall into the following 12 aromatic hydrocarbon series: naphthalene (m/z 128, m/z 142, m/z 156, m/z 170, m/z 184, m/z 198), phenanthrene (m/z 178, m/z 192, m/z 206, m/z 220), benzopyrene (m/z 252), fluoranthene (m/z 202, m/z 216), dibenzothiophene (m/z 184, m/z 198, m/z 212, m/z 226), benzonaphthothiophene (m/z 234), dibenzofuran (m/z 168, m/z 182, m/z 196), fluorene (m/z 166, m/z 180, m/z 194), chrysene (m/z 228, m/z 242, m/z 256), biphenyl (m/z 154, m/z 168, m/z 182), triaromatic sterane (m/z 231) and benzohopane (m/z 191).