Dear Colleagues,

My research group has been exploring the use of stable isotopes (C, H, S)
in organic compounds (oils, lipids, gases, etc.) to fingerprint and track
them (CSIC).

Recently, we have turned our attention to the release of tetraethyl and
tetramethyl lead from gasoline into soils. This topic certainly must sound
very familiar to many of you. The twist, that we need your help with, is as
follows.

In our study area,  there may have been multiple release events that took
place over decades. This can confuse the light element isotope fingerprint.
Therefore I am interested in knowing if the isotope composition of lead
could be a potential candidate to fingerprint. In order for this to work,
there must be measurably different and diagnostic lead isotope compositions
in the feedstock for TEL and TML.

The best case scenario is if the source of lead for TEL and TML was
different at different times, and that the lead isotope composition for the
sources was different. If this is the case, then we could "date" the
releases (obviously not radiogenically, but akin to Freon dating in the
ocean).


Questions:

1. Over the past decades, have there been numerous sources for the TEL and
TML feedstock?

2. Was the lead for the TEL and TML feedstock generation a unique source?

We would appreciate it if you can help, make suggestions or know of
publications on this topic - even a response that refutes the idea would
guide us.

Thank you


Michael Whiticar
([log in to unmask])




__________________________________________________________
Dr. Michael J. Whiticar
Professor
Biogeochemistry
School of Earth and Ocean Sciences
University of Victoria

Email:                  [log in to unmask]
Web Page:                       http://ceor.seos.uvic.ca/biogeochem/

Phone/Fax Numbers:
My Office:                      250 721 6514 (me sometimes and voice mail)
Biogeochemistry Facility:        250 721 6183
Gonzales Observatory:   250 595 6743

Main SEOS Office                250 721 6120
Fax:                                    250 472 4620 (E-Hut)
                                        250 721 6200 (Main Office)

Campus and Street Addresses
Office:                                 E-Hut, Room 118, UVic
Biogeochemistry Facility:        E-Hut, Room 102, UVic
Gonzales Observatory            Denison Road, Victoria

Mailing address:
SEOS, UVic
P.O. Box 3050
Victoria,
Beautiful British Columbia
V8W 2Y2
Canada