Teledyne Leeman Labs Blog

The U.S. Department of Energy (DOE) has released a new plan to address the Environmental Management (EM) challenge of mercury contamination at two sites in Tennessee and South Carolina. The plan “advocates for research and the development of technologies that could resolve key technical uncertainties with mercury in environmental remediation, the deactivation and decommissioning of facilities, and processing waste in tanks.”

A research team at Flinders University in Australia has “developed an inexpensive, non-toxic polymer that can absorb hazardous mercury compounds out of water and soil.” The secret ingredient of the polymer is a colorless liquid hydrocarbon that is extracted from the peel of citrus fruits such as lemons, limes and oranges. The process to extract limonene, which gives citrus fruits their smell, includes centrifugal separation and steam distillation.

According to a paper published in the journal Angewandte Chemie International Edition, limonene is combined with an equal mass of molten sulfur and synthesized to form a sulfur-limonene polysulfide compound. The two-phase mixture becomes a single, dark red phase upon reaction. The mixture turns a bright yellow in the presence of mercury.

While mercury levels in rainfall and other forms of precipitation have fallen along the East Coast, other sites in the center of North America are reporting increased levels of the toxic element, pushing overall trends for the continent in a positive direction.

Mercury Analysis Systems

In our previous blog post “What is Cold Vapor Atomic Absorption (CVAA) Spectroscopy?” (HERE), we discussed CVAAS as a primary technique for mercury analysis and determination. In this post, we will describe Teledyne Leeman Labs’ mercury analyzers (analysers outside of the US and Canada) that use the CVAAS process.

Leeman Labs offers two CVAA systems for mercury determination: the Hydra II_AA , which is an entry-level CVAA system that can detect mercury limits of less than 5.0 ng/L with a usable range of 5 ng/L to 1 mg/L; and the QuickTrace® M-7600 CVAA mercury analyzer, which is a dual-beam system capable of ultra-trace detection limits of less than 0.5 ng/L.

Scientists from Japan, Russia and America recently made all science textbooks obsolete when the four new elements they discovered were officially added to the periodic table, completing the 7^th period of the table of elements. The first elements added to the table since 2011 were verified by the U.S.-based International Union of Pure and Applied Chemistry (IUPAC), the global organization responsible for governing chemical nomenclature, terminology and measurement.

Teledyne Leeman Labs offers a family of fully automated mercury analyzers that address the analysis of solids, semi-solids and liquids. Our high performance instruments help lab technicians, chemists and lab managers to complete the myriad of task required in today’s modern laboratories.

We recently released a Practical Guide for Selecting the Best Technique for Mercury Measurement where we describe in detail each of our mercury analyzers and how they work. In a previous post, we covered our two CVAAS systems. Below is a summary of the information included in the guide about Leeman Lab’s Cold Vapor Atomic Fluorescence Spectroscopy and Direct Analysis Combustion systems. The complete guide can be downloaded at TeledyneLeemanLabs.com.

Cold Vapor Atomic Absorption Spectroscopy or CVAAS is one of the primary techniques for mercury analysis. Introduced in 1968 by Hatch and Ott, CVAAS is now the reference method for drinking water monitoring under the Safe Drinking Water Act passed in 1974, and amended in 1986 and 1996. The technique was introduced to the market following the first commercially available atomic absorption spectrometer, which measures quantities of chemical elements present in environmental samples.

Atomic Absorption Spectrometry (AAS) determines the quantities by “measuring the absorbed radiation by the chemical element of interest. This is done by reading the spectra produced when the sample is excited by radiation.”[i] CVAAS was born when Hatch and Ott used an attachment for a flame atomic absorption spectrophotometer that enabled the reduction of Hg2+ in a solution to ground state atoms (Hg0). The ground-state mercury atoms were then transported to an optical cell and detector for measurement. Shortly after Hatch and Ott introduced the technique to the market, the United States EPA adopted CVAAS for the determination of mercury in water, soil and fish.

A recent feature story from CBCNews details the unregulated use of mercury as part of mining operations across South America. The article includes the story of Brandon Nichols, a University of British Columbia grad student who ventured south to research small-scale gold mining operations in Ecuador. His experience included mercury poisoning “two or three times,” including “serious headaches.”

According to the article, “Mercury is widely used by the miners because it bonds with gold, allowing it be more easily separated from the ore hauled out of countless mines dotting the countryside.”

Nichols recorded hours of video of the mining and processing techniques that used the toxic liquid metal, and questioned whether cleaning the toxic workshops would ever be possible.

Selecting the right mercury analysis technique ultimately depends on your specific analytical needs. For many laboratories, particularly those involved in environmental analysis, the decision will be driven solely by the need to comply with a specific regulatory method.

The regulatory methods include:

• Cold Vapor Atomic Absorption (CVAAS)
• Cold Vapor Atomic Fluoresence (CVAFS)
• Direct Analysis or Thermal Decomposition

Could your next batch of French fries be cooked in insect oil? Researchers at the University of Wageningen in the Netherlands believe that the search for a protein source to alleviate pressures on the global food supply may have also stumbled across another use for insects: fats and oils. Production of soy, sunflower and palm oil require significant land resources to produce the oil, putting pressure on natural resources and the environment. As companies have worked to isolate the protein in insects, they have been discarding the oils, which researchers believe can be used for both edible and non-edible purposes.