Development of continuous on-line purge and trap analysis

Abstract

An on-line purge and trap system for continuous monitoring of Volatile Organic Compounds (VOC) is presented. The purge chamber was designed for continuous extraction of VOC from water with nitrogen. The analytes were preconcentrated on a microtrap prior to analysis by GC with flame ionization detection. The microtrap served as a fast injection device for carrying out analysis at high frequency. Continuous monitoring was accomplished by performing injections at fixed intervals. This system showed high sensitivity, high precision, detection limits at the ppb level, and stable response over long periods of continuous operation. Factors affecting system performance were studied. A predictive model based on gas-liquid partitioning is also presented.

Automatic On-Line Purge-and-Trap Sequential Injection Analysis for Trace Ammonium Determination in Untreated Estuarine and Seawater Samples

“…The optimum depths vary between 4.0 and 7.0 cm. For higher depths, the effectiveness is decreased to some extent, as it is also referred previously [27].…”

Methane preconcentration in a microtrap using multiwalled carbon nanotubes as sorbents

“…However, this is a challenging task because while the concentration of CO 2 is relatively high, the concentration of organic species such as CH 4 are relatively low (ppm to ppb), and some level of preconcentration is necessary * Corresponding author. for their monitoring, especially for on-line and field monitoring [5][6][7][8][9][10][11].…”

Determination of trace compounds and artifacts in nitrogen background measurements by proton transfer reaction time‐of‐flight mass spectrometry under dry and humid conditions

“…In many analytical procedures and catalytic reactions, the utilization of inert gases, such as nitrogen, helium, or argon, is unavoidable. Nitrogen is used in many applications, for example, purging gas in sampling methods, 1–3 carrier gas in diluting and gas generating systems, 4–9 in surface area measurements of porous materials, 10,11 as reactant in the Haber–Bosch process, 12 in cryogenic sampling applications, 13,14 and as carrier gas in gas chromatography (GC) 15–17 . Because in all of these applications the gas quality used is usually 5.0 (99.999% purity) or 6.0 (99.9999% purity), the remaining volatile organic compounds (VOCs) and water do not pose an interference to the different applications.…”