Accurate Quantitation of Trace-Level Volatiles In Water
Volatile organic compounds (VOCs), which have been found to be harmful to the environment as well as toxic to humans, are monitored in both drinking water and wastewater supplies by environmental regulators. Due to their widespread use across multiple product lines, VOCs have many routes to enter the environment. VOCs are found in a variety of products from paints and hydraulic fluids to dry-cleaning products and refridgerants as well as petroleum based products and gasoline. Automotive and industrial emissions represent two of the largest contributors that widey disperse VOCs into the environment. After being dispersed, they settle on soil and vegetation and are then washed into stormwater via rain and other precipitation. VOCs comprise a large and disparate list of compounds that include more common compounds including nitrosamines, aldehydes, ketones, halogenated compounds as well as several other potentially harmful compounds.
Accurate, reliable and efficient trace-level analyses of VOCs are required and needed to accurately measure and monitor VOC levels. Regulatory agency around the world have set limits for and monitor maximum contamination levels for several VOCs. Regulatory agencies set the VOC threshold limits based on threat, toxicity, and target matrix. While VOC contaminants are often analyzed via GC or GC/MS, it can be difficult to guard against potentially costly and dangerous false positives. To meet this challenge, Agilent developed the Inert Flow Path for GC. The Inert Flow path includes GC components from injector to detector resulting in a reliable inertness level that prevents cross-contamination enabling very accurate quantification of VOCs.
Agilent's 7697A Headspace Sampler, when coupled with the market leading 7890 GC and 5977B Mass Spectrometer, delivers accurate and reliable analysis of VOCs in water. Purge & Trap techniques, that are supported by Agilent, is another way to analyze regulated VOCs in water using GC-MS.
The revolutionary design of the high efficiency source (HES) MS produces a higher ion current yield for many compounds. The added benefits of providing greater sensitivity and more flexible approaches to sample analysis yields benefits including as lower detection limits, reduced sample size, and quicker analysis. This setup, used in conjunction with Selected Ion Monitoring (SIM), delivers parts-per-trillion (ppt) limits of detection for VOCs analysis by the 5977B GC/MSD. For the lowest detection levels, elimination of interferences and widest scope, the use of multiple reaction monitoring (MRM) on the GC/MS/MS for VOCs is also possible.