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Identification and evaluation of long-term markers is crucial in prolonging the detection window for anabolic steroid abuse in sport. Recently, sulfoconjugated epiandrosterone was identified as a potential long-term marker for the abuse of certain endogenous anabolic agents, including testosterone, which continues to be widely used as a performance enhancing agent in sport. To evaluate the applicability of epiandrosterone sulfate as a marker for testosterone use, administration studies were conducted with multiple modes of testosterone administration - transdermal, intramuscular, and subcutaneous. A modified sample preparation method was used to collect both glucuronidated and sulfoconjugated analytes of interest. Carbon isotope ratio measurements from the administration studies are presented here. Epiandrosterone was less effective than the conventionally used target compounds for detection of the low dose application (transdermal gel). With intramuscular administration, epiandrosterone was more diagnostic than with transdermal administration, but it did not prolong the detection window more than the conventional target compounds. With subcutaneous administration, the doses administered to the subjects were varied and the effect on the epiandrosterone values was dependent on the magnitude of the dose administered. Epiandrosterone does not appear to be a useful marker in the detection of low dose testosterone administration. It is responsive to higher dose administration, but it does not provide an extension of the detection window relative to conventional target compounds.

Leaf-wax n -alkanes 2 H/ 1 H ratios are widely used as a proxy in climate reconstruction. Although the broad nature of the relationship between n -alkanes δ 2 H values and climate is appreciated, the quantitative details of the proxy remain elusive. To examine these details under natural environmental conditions, we studied a riparian broadleaf angiosperm species, Populus angustifolia , growing on water with a constant δ 2 H value and monitored the δ 2 H values of leaf-wax n- alkanes and of stem, leaf, stream, and atmospheric waters throughout the entire growing season. Here we found the δ 2 H values of leaf-wax n -alkanes recorded only a 2-wk period during leaf flush and did not vary for the 19 weeks thereafter when leaves remained active. We found δ 2 H values of leaf-wax n -alkanes of P. angustifolia record conditions earlier in the season rather than fully integrating the entire growing season. Using these data, we modeled precipitation δ 2 H values during the time of wax synthesis. We observed that the isotope ratios of this precipitation generally were 2 H-enriched compared with mean annual precipitation. This model provides a mechanistic basis of the often-observed 2 H-enrichment from the expected fractionation values in studies of broadleaf angiosperm leaf-wax δ 2 H. In addition, these findings may have implications for the spatial and temporal uses of n -alkane δ 2 H values in paleoapplications; when both plant community and growth form are known, this study allows the isolation of the precipitation dynamics of individual periods of the growing season.