In this paper we describe general relationships between stable isotopes of carbon, nitrogen, and hydrogen in bacteriological culture media and spores of Bacillus subtilis, an endospore-forming soil bacte...Since the anthrax attacks of 2001 the need for methods to trace the origins of microbial agents has become urgent. Here "age" of a seized cocaine specimen is defined as the time period between when a coca leaf...Hydrogen peroxide (H(2)O(2)) is a widely used oxidizer with many commercial applications; unfortunately, it also has terrorist-related uses. Michael has 2 jobs listed on their profile. Forensic practitioners use fundamentals of chemistry and physics to examine evidence and infer its origin. Here we report that high-precision oxygen isotope ratio measurements of water (+/-0.13 per thousand) were rapidly and routinely made on small samples (40-100 microL) using an isotope ratio mass spectrometer operated in continuous-flow mode. We present a surve...Bacillus subtilis, a Gram-positive, endospore-forming soil bacterium, was grown in media made with water of varying oxygen (delta(18)O) and hydrogen (deltaD) stable isotope ratios. Thirty-one percent of beers had a carbon signature of C(3) plants (barley, rice, etc.
Oxygen and hydrogen stable isotope rati...The carbon isotope ratios (delta(13)C) of 160 beers from around the world ranged from -27.3 to -14.9 per thousand, primarily due to variation in the percentage of C(3) or C(4) plant carbon in the final product. Water can evaporate from agar (solid) media during culturing, changing its isotope ratios. Check out some of the IMDb editors' favorites movies and shows to round out your Watchlist. Two replicate 1 mL aliquots of atmospheric air are sequentially sampled from fifteen 100 mL flasks. We present a survey of...The stable isotope ratios of a seized pathogen culture could potentially reveal information about the environment in which the agent was produced. Water used for maize production in these arid zones could have come from precipitation and runoff during the summer monsoon, from perennial streams and springs, or from stored soil water fed by snowmelt. Michael Lott was born in June 1964 in Hamburg, Germany. The stable isotope ratios of bacteria record information from both the nutrients and the water used to make their culture media and could potentially be used to provide information about their growth environment. Continuous-flow elemental analysis-isotope ratio mass spectrometry was utilized to measure changes in the stable isotope ratios...Stable isotope ratios of hydrogen and oxygen in microbes have been shown to be functions of the corresponding isotope ratios of the water with which the culture medium was prepared, and thus to contain a potential geographic signal.
As quantitative conversion of nitrogen in some materials (i.e., nitrate salts and nitro-organic compounds) is difficult, this study tests a recently published method – thermal decomposition without the addition of O2 – for the analysis...RATIONALEBecause of the threat of bombings using improvised explosives containing ammonium nitrate (AN), law enforcement and intelligence communities have been interested in stable isotope techniques for tracking and discriminating AN sources. The objective of this study was to determine the extent to which Δ(14)C analyses could quantify the "age" of recent cocaine seizures. The binder and plasticizer of a plastic explosive were extracted into cy-clohexane, leaving the explosive components and other insoluble material. As expected, the range of hydrogen (δ(2)H, 230‰) and oxygen (δ(18)O, 24‰) isotope values of...Two 14 C calibration curves have been produced that allow determination of the statistical average age of coca leaf and cocaine base specimens produced for the time period 1979–2009.