Tracking historical sources of polycyclic aromatic compounds (PACs) in dated lake sediment cores near in-situ bitumen operations of Cold Lake, Alberta.

Most bitumen in the Alberta oil sands (Canada) is extracted by thermal in-situ recovery. Despite the widespread use of in-situ bitumen extraction, little information is available on the release of petroleum hydrocarbons by this method to adjacent land and water. Here we analyzed the composition and abundance of parent and alkylated polycyclic aromatic compounds (PACs) in 11 radiometrically-dated lake sediment cores collected near in-situ operations at Cold Lake Alberta to assess potential petroleum contamination sources to surrounding lakes over the past century.

Rapid and efficient autoclave digestion for the extraction of iodine-129 from urine samples.

A new method was developed to extract I from urine samples and measure it using accelerator mass spectrometry (AMS). The samples were pre-treated in an autoclave with hydrogen peroxide and were then acidified with nitric acid, followed by the precipitation of iodine as silver iodide (AgI) for measurement by AMS. This new procedure is substantially faster than previous methods for the extraction of iodine from urine and results in less chemical waste.

Assessing the uranium DGT-available fraction in model solutions.

The uranium speciation in humic acid (HA) and fulvic acid (FA) model solutions was investigated by diffusive gradients in thin films (DGT). A reference solution was used to normalize the DGT data from different samples. This approach was used to assess uranium DGT-available fraction (F), which was calculated from experimental data and reflect both the mobility and lability of uranium species.

Measuring (210) Pb by accelerator mass spectrometry: a study of isobaric interferences of (204,205,208) Pb and (210) Pb.

Rationale: The measurement of (210) Pb provides an assessment of the risk an individual faces of developing lung cancer as a result of their exposure to radon and radon decay products. Existing radiometric techniques are not sensitive enough to detect (210) Pb in many exposures. This report describes the further development of a method of measuring (210) Pb using Accelerator Mass Spectrometry (AMS).

Detection of (135) Cs by accelerator mass spectrometry.

Rationale: The ability to measure both (135) Cs and (137) Cs can provide an estimate of the age and source of Cs isotopes in an environmental sample. Accelerator mass spectrometry (AMS) consistently reports lower abundance sensitivities than other techniques and, with the addition of an on-line reaction cell, simpler isobaric suppression. Therefore, an AMS methodology was developed to measure Cs isotopes using CsF2- as the initial anion.