Dan Cornford
It is with deep sadness that we must share the news that Dan passed away on Thursday 10th September after a short illness. Our thoughts and most sincere condolences are with Dan’s family during this most difficult time.
Director & Technical Advisor
It is with deep sadness that we must share the news that Dan passed away on Thursday 10th September after a short illness. Our thoughts and most sincere condolences are with Dan’s family during this most difficult time.
By Paul Farrimond
25-Norhopanes have been reported in biodegraded oils since the late 1970s, and Seifert & Moldowan (1979) proposed that the methyl group at C-25 in the regular hopanes was removed by microbial demethylation associated with the degradation at the oil/water contact of an oil accumulation.
Meeting in Sheffield on 18-19 June. IGI are pleased to be continuing our regular sponsorship of this conference – an annual meeting that mainly promotes student research projects in this field.
By Paul Farrimond
These aromatic biomarkers are unfortunately rarely used in petroleum geochemistry. They have the five-ring structure of the hopanes but with an aromatic ring fused to the E-ring in place of the normal side chain.
Although an unfamiliar molecule to many petroleum geochemists, bacteriohopanetetrol (BHT) is nevertheless an important one, being a major source of the hopanes found in oils and their source rocks (Ourisson et al. , 1984).
By Paul Farrimond
Oleanane is present in only some oils and source rocks. It occurs as two isomers – 18α(H) and 18b(H) – and is typically found as a doublet peak in the m/z 191 mass chromatogram eluting just before the C30 αb hopane.
By Paul Farrimond
The C29 hopane, 30-norhopane, is not only a member of the series of regular hopanes but also of a less common series that lack the methyl group at C-22 in the side chain, the 30-norhopanes.
This unusual hopane-like compound is recognised together with the hopanes in the m/z 191 mass chromatogram and was for many years used as a biomarker of hypersalinity due to its common high abundance in sediments deposited under such conditions.  However, a key paper by Sinninghe-Damsté et al.
with Paul Farrimond
Apologies for beginning this note with some history… When I worked on my Ph. D. project in the mid-1980s I witnessed the arrival of the first desk-top computers into our laboratory in Bristol.  They were expensive and clunky, and we only had a few.