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Posts Tagged ‘Chromatography’

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

Monday, 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.

Read more about Qualitative Aspects of Environmental Testing…

Ultra-Trace Arsenic Speciation at Columbia Analytical

Thursday, September 24th, 2009

Arsenic Speciation

Ultra-trace speciation of arsenic and other metals is performed using a variety of techniques tailored to the specific combination of species, matrix, and detection limits required. Currently, two analytical systems are applied: Ion Chromatography-Inductively Coupled Mass Spectrometry (IC-ICP-MS) and Hydride Generation-Cryogenic Gas Chromatography-Flame Atomic Absorption Spectrometry (HG-CGC-AAS). Each of these techniques has particular strengths that can be exploited depending upon the scientific question being asked. These techniques are combined with specific extraction techniques in order to maximize speciation integrity and data quality.

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