Techniques Used in Environmental Labs

April 5, 2009

Main Library

Because some analytes are light sensitive, samples must be placed in an amber container rather than a clear one.

Usually, an equal volume from each of the bottles is poured into a consolidation container and then passed on to the appropriate lab for analysis.

Hydrogen ion concentration (pH), for example, must be analyzed immediately whereas O&G can sit on the shelf for 28 days or less.

Ion Chromatography (IC) is a method of liquid chromatography that is conducted in the Wet Chemistry lab.

There are primarily four types of detectors employed in environmental labs: Thermal Conductivity Detector (TCD), Flame Ionization Detector (FID), Electron Capture Detector (ECD), and Photoionization Detector (PID).

The electron stream is then sent through a polarization circuit, which sees a current.

The sample is atomized in one of two ways, either through flame atomization or flameless atomization.

The AA is used for Mercury analyses because of the minute detection limits.

As mentioned above, the atomizer of choice is the graphite furnace.

Quality assurance as defined by the Standard Methods for the Examination of Water and Wastewater, 20th edition is the “definitive program for laboratory operation that specifies the measures required to produce defensible data of known precision and accuracy.”

The first three points prove the lab can perform the analyses with good repeatability and meet the minimum detection limit.

The QA/QC plan will contain the aforementioned elements but will also include lab SOPs (Standard Operating Procedures).

— Utilizes flame (H2 + air) which ionizes organic compounds into e- & positive ions.

megarust (0 downloads)

No comments yet.

Leave a Reply