Lab Science News - Science, chemistry and environmental news from laboratory experts

Sample Containers & Preservation for Mercury Analysis in Waters

July 30th, 2013

By Tim Crowther, Regional Client Services Manager, ALS Environmental – Canada

**NOTE: The content in this article does not apply to ALS Environmental’s USA locations.**

On August 15, 2013, ALS Canada will begin supplying our clients with borosilicate glass containers with Teflon® lined caps for the collection of total and dissolved mercury in all water samples. Hydrochloric acid (HCl) preservative will also be supplied. Recent literature and ALS experimental test results indicate a glass container with HCl preservation is the most effective method for reducing mercury losses following sample collection. The sample bottle and preservative pictured overpage will be the recommended container for low-level total and dissolved mercury (≥10 ng/L), which were previously collected in a high-density polyethylene (HDPE) ‘plastic’ bottle with nitric acid preservation. HDPE containers are not suitable for ultra-trace level (0.2 – 10 ng/L) mercury analysis. Ultra-trace mercury sampling requires more sample volume, as well as the use of cleaner sample handling and analysis procedures.

The British Columbia Ministry of Environment (BC MoE) will require the use of Teflon® or borosilicate glass containers with HCl preservation for the collection of water samples for mercury analysis effective November 15, 2013. The United States Environmental Protection Agency (US EPA) and the Ontario Ministry of Environment have already prescribed the same. Various other agencies are considering similar changes, including the Canadian Council of Ministers of the Environment (CCME) and Alberta Environment.

Additionally, ALS recommends that filtration for dissolved mercury analysis be conducted within one hour of sample collection using a suitable in-line filter or 0.45 μm syringe filter supplied by ALS.

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Qualitative Aspects of Environmental Testing for Organic Parameters – An Overlooked Facet of Data Quality

May 27th, 2013

By Lee Wolf, Regulatory Affairs Manager, ALS Environmental – USA

One may look at classical wet chemistry and the pioneering chemists and wonder. What were they really doing? What were they looking for? Discovering tests for isolating and identifying chemical components was the purpose. One cannot envision that accuracy and precision, or detection limits were of much concern. Fast-forward to the infancy of environmental testing and one can still find the identification of chemical components of utmost importance in developing methods and technology.

Currently, and for recent years, the focus of environmental measurements has predominately been on quantitative aspects. Significant emphasis is now put on detection limits, quantitation limits, accuracy and precision, and uncertainty of measurements. That is, an emphasis on sensitivity over selectivity, both in terms of data quality and data usability. Yet fundamentally, the targeted component(s) of a sample must first be accurately identified before accurate quantitation can occur.

In this paper, the shift in focus from selectivity to sensitivity in the analysis of organic compounds will be discussed and potentially overlooked qualitative data quality considerations examined. Examples of the reliance on standard methodologies and how they can lead to qualitative errors is examined, and how the need for a strong understanding of method selectivity and the use of qualitative tools is important.

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Improved Method for Petroleum Hydrocarbons in Solids

March 1st, 2013

By Mark Hugdahl, Technical Director, ALS Environmental – Canada

Beginning April 1, 2013, the ALS Environmental laboratory in Winnipeg will begin the use of a new and improved analysis method for Petroleum Hydrocarbons in soils and other solids. The Microscale Solvent Extraction (MSE) Technique has been used successfully at other ALS Canada laboratories for almost five years and is now available at ALS Winnipeg as a CALA accredited test procedure.

The MSE method, also known as the “Tumbler” extraction technique, will be used for the analysis of CCME Petroleum Hydrocarbon fractions (F2-F4G) in soils, sediments, sludges, and wastes. The method has been demonstrated to meet all regulatory requirements specified by CCME and all provincial jurisdictions where ALS Canada operates.

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PAH Analysis: Expanded Compounds of Concern and Advancements

September 5th, 2012

By Lee Wolf, Regulatory Affairs Manager, ALS Environmental – USA

As a class of organic compounds, PAHs are characterized by bonded aromatic rings that do not typically carry other functional groups or branched groups substituted for hydrogen atoms. PAHs occur in fossil fuel materials such as oil, coal, tar and fuels. They are produced as a result of fuel burning. They are also found in products such as burned tobacco, incense, and some plant-based oils. To further understand the sources of PAHs, they may be classified as follows:

  • Petrogenic – These are PAHs derived from petroleum inputs and generally associated with fossil fuels.
  • Pyrogenic – These are PAHs which are derived from combustion sources.
  • Biogenic – These are PAHs formed from natural biological processes.

The toxicity of PAHs is dependent upon the structure or arrangement of aromatic rings. For example, the toxicity of some PAH isomers (with the same formula and number of rings) can vary from being effectively nontoxic to being very toxic. The more toxic or carcinogenic PAHs may be small or large. The USEPA has identified seven PAH compounds as probable human carcinogens.

Read more about PAH Analysis…


Theoretical Gypsum Requirement (TGR) Models

July 6th, 2012

By John Ashworth,  ALS Environmental – Canada

ALS Environmental Lab TestingGypsum is often applied as an amendment to soils that exhibit a high sodium adsorption ratio (SAR).  The addition of gypsum can reduce a soil’s clay plasticity, thus improving drainage and ease of cultivation. Estimating the correct amount of gypsum required to remediate a particular site is an inexact science requiring experience and consideration of specific site history and conditions, but models described in the literature can produce theoretical estimates to provide guidance.  As a service to our clients, ALS now offers two theoretical calculations for gypsum requirement that are suited to two common categories of salt-impacted soil on the Canadian prairies.


Ammonia: All You’ve Ever Wanted To Know

June 20th, 2012

By Mark Hugdahl, Technical Director,  ALS Environmental – Canada

The synthetic production of ammonia by the Haber-Bosch process has been called the most important invention of the 20th century. Fritz Haber received the Nobel prize in 1919 for pioneering the “fixation” of nitrogen, where nitrogen gas is converted to ammonia, a reactive form of nitrogen that can easily be taken up by plants. Nitrogen from synthetic fertilizers now provides more than half of the nutrients required by the world’s crops. Without the ammonia produced from the Haber-Bosch process, our planet could not feed seven billion people.

Ammonia plays a key role in the global nitrogen cycle, and is produced naturally through the decomposition of nitrogen-rich organic matter. However, it is also a very common environmental pollutant, and in 1990 was listed as the top priority on Environment Canada’s Canadian Chemical Spill Priority List. Outside the fertilizer industry, anthropogenic point sources of ammonia include the textile industry, household chemicals, explosives, the plastics industry, oil refineries, iron and steel mills, meat processing plants, and sewage treatment plants.

At low levels, ammonia in drinking water is not considered toxic to humans. It is produced naturally in the human body, and is efficiently targeted and detoxified by specific enzymes. However, ammonia is highly toxic to fish and amphibians at very low concentrations, since they lack these enzymes.

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Allowable Levels Established for DEHP in Bottled Water

January 17th, 2012

bottled-waterIn April 2012, the Food and Drug Administration (FDA) will begin regulating the level of di(2-ethylhexyl)phthalate (DEHP) in bottled water. Manufacturers will be required to annually monitor their finished bottled water products and source water for DEHP in order to maintain compliance with current good manufacturing practice (cGMP) regulations.

Read more about the allowable levels for DEHP in bottled water…