Teledyne Leeman Labs Blog

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

Since the 1970s, petrochemical labs have used Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES) as a key technique to determine a range of elements and concentrations in both aqueous and organic samples. ICP is compatible with a variety of organic solvents, which means it permits the preparation of a broad range of sample types using a simple dilution.

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.

Soil and dust in homes often become the primary resting places for environmental toxins such as metals and metalloids that come from vehicle traffic and a variety of industrial sources. Residents within urban settings have a higher rate of exposure to contaminated dust from inhalation, ingestion and dermal contact. As a result, dust ingestion is often regarded as the primary source of low-dose mercury in urban children who spend much of their time indoors.

Since the 1970s, scientists have analyzed lake sediment and ice cores to understand the levels of historical atmospheric mercury emissions from metal production and industrial activity. Much of the published ice core mercury record has come from a glacier in Wyoming.  While the record has been cited extensively in scientific literature, many modern day scientist argue that it does not truly represent the global trends in atmospheric mercury levels.

The Animas River is a 125-mile river in the western United States that feeds the Colorado River. On August 5, 2015, a crew from the U.S. Environmental Protection Agency (EPA) was pumping out water from the abandoned Gold King Mine in Southern Colorado when heavy equipment used by the workers caused a leak.  

Steel is critical to our modern world, with companies producing more than 1.6 billion tons every year[i]. When it comes to high-carbon steel, the higher the carbon content, the harder and stronger the steel is.  As carbon is reduced, the iron becomes more flexible and easier to form. Carbon steel makes up more than 85% of the steel produced in the United States, and while other alloys can be used to change steel properties, such as Manganese and Vanadium, carbon is the most cost-effective alloying material for iron.

Recent accidents in industrial laboratories across the country have raised questions about lab safety programs, and whether enough is being done to instill stronger safety cultures. In particular, there are major concerns in these cultures in nonindustrial settings where serious incidents have taken place.

Leaders from the chemical industry published a letter in Chemical & Engineering News expressing their concerns with the “wide gulf in safety cultures,”[i] stating, ““The facts are unequivocal. Occupational Safety & Health Administration statistics demonstrate that researchers are 11 times more likely to get hurt in an academic lab than in an industrial lab. There have been serious accidents in academic labs in recent years—including fatalities—that could have been prevented with the proper use of protective equipment and safer laboratory procedures.”[ii]