Analytical laboratories gasoline age dating analysis
Thermal Desorption Tubes Methods such as EPA Method TO-17 (1999), EPA IP-1B (1990) and/or NIOSH 2549 (1996) use stainless steel thermal desorption tubes (packed with one or multiple sorbent materials) and a personal sampling pump to sample for VOCs in indoor/ambient air.In general, thermal desorption methods were written to detect low concentrations of VOCs in indoor/ambient air, with reporting limits typically in the low ppb V (µg/m3) range.For TVOC measurement, the analytical technique used must always reference one compound for calibration purposes.All compounds detected are then assumed to have the same response factor as the calibration compound.However, none of these sampling and analytical methods address TVOC in particular, and thus the existing methods must be modified.In addition, TVOC is not defined (in terms of boiling point range, etc.) in the latest LEED-NC guidance and therefore is left open for interpretation; historically, many definitions of “TVOC” exist in literature.Since only a very small portion of the sample (approximately equivalent to 1/1000th of the volume of air sampled) is being analyzed, the sensitivity of the analysis is only moderate (although completely adequate for traditional workplace exposure monitoring).
Mass spectrometry is the most widely used analytical tool for environmental analyses due to their sensitivity, reliability, and versitility.
Background Total Volatile Organic Compounds (TVOC) may be evaluated when building designers/managers are pursuing the Leadership in Energy and Environmental Design Green Building Rating System for New Construction (LEED-NC) EQ Credit 3.2.
The latest LEED-NC guidance document specifies that the maximum allowed concentration of TVOC measured in a building (post construction, pre-occupancy) is 500 µg/m; the guidance also mentions using the sampling/analytical methods in the US EPA Compendium of Methods for the Determination of Air Pollutants in Indoor Air.
Instrumentation in the Water Sciences Laboratory is used for developing and applying methods to accurately measure very low concentrations of organic contaminants such as pesticides, munitions waste, both steroids and veterinary pharmaceuticals/antibiotics from concentrated animal feeding operations (CAFOs), algal toxins, gasoline additives, and degradation products in a wide variety of matrices.
Many new methods have been developed in this facility using state-of-the-art instrumentation for analysis of various chemical species such as arsenic, selenium, iron and emerging contaminants like glyphosate and its metabolites.
Search for analytical laboratories gasoline age dating analysis:
When using this technique to evaluate TVOC for LEED, it may be necessary to increase the sampling flow rate and/or sampling duration to lower the detection limit below 500 µg/m3.