The Ultrachron

Analyzing Tiny Time Crystals with the Ultrachron: The Ultrachron is an electron microprobe designed to analyze grains of monazite, a mineral that contains rare earth metals cerium, lanthanum, and neodymium. In some monazite crystals, uranium and thorium are also present. Because these latter two elements undergo radioactive decay in a predictable time pattern, their presence turns monazite into a tiny timekeeper.

More information about the Ultrachron and its research applications is available at: Ultra-Chron Project.

Sorting Out Lead Levels

Concern over the presence of the lead in various sources of drinking water result in an analytical chemistry challenge, because of the need to avoid contamination of the vessels and apparatus. Inadequate attention to this problem has resulted in conflicting reports of the lead concentrations measured in bottled waters. One solution is described by Shotyk and Krachler and applies clean-room procedures and high-sensitivity detection technology that was developed to gauge the nanogram-per-liter concentrations of lead present in polar ice to the measurement of lead levels in commercially available bottled waters from across the world and artesian flow sources in southern Ontario, Canada. The measured concentrations were below the 10microgram/liter level considered hazardous. However, glass bottles appeared to leach lead over time, roughly doubling concentrations from ~100 to ~200 ng/liter in water stored in them over 6 months. Concentrations measured in plastic bottles ranged from <1 to 761 ng/liter. However, other organic materials unanalyzed in this study may be leaching out of the plastic. The artesian sources exhibited a narrowly ranged lead concentration having a median of 5.1 ng/liter.

This abstract is based on that presented in the Editor's Choice list of ScienceMag.org: here. Full details were published in Environ. Sci. Technol. 41, 10.1021/es062964h (2007).