Nitrogen Purge Condition for Simultaneous GC/MS Measurement of Chemicals

Abstract

Environmental monitoring of chemicals is important for risk evaluation. As almost all contaminants exist in water environments at very low concentration, appropriate concentration procedures are required. A nitrogen purge process has been used to concentrate extract containing various trace semi-volatile organic chemicals by combination with a solid-phase extraction. However, recovery loss is often caused depending on the purging conditions, and it decreases the reliability of the measurement. In this study, 166 chemicals of various physical properties were prepared and their recovery ratios were investigated under each condition. The recovery ratios in nitrogen purge were not necessarily determined by their physical properties, or overly influenced by the nitrogen purge volumetric flow rate. In contrast, the control of the solvent volume, which changes with the progress of the nitrogen purge concentration, was important in addition to the alternation of the final solvent from hexane to acetone, because the concentration of chemicals in the solvent was one of the key factors determining the recovery ratios in the nitrogen purge process. The variation of the recovery ratio was acceptably small under appropriately controlled conditions.

Modeling of nitrogen solubility in normal alkanes using machine learning methods compared with cubic and PC-SAFT equations of state

“…Also, in the midstream, N 2 is used in pipeline drying, which is an essential part of pipeline commissioning to prevent unwanted aerosols through contaminant displacing 23 . There are many significant instances of N 2 usage in downstream, like nitrogen purging which is a technique to avoid unintentional reaction of hazardous gas and hydrocarbons through the oxygen reduction in the environments that is susceptible to explosion 24 that is a similar technique which is used in nitrogen blanketing 25 in hydrocarbon storage tanks. Crude oil is a complex mixture of hydrocarbons.…”

Detection of Japanese PRTR Chemicals in a River Affected by Effluent from Industrial and Sewage Facilities

“…Details of the SPE, nitrogen gas purge procedure and recovery ratio followed the conventional method (Kameya et al, 2010;Jinya et al, 2011;Kameya et al, 2012;Jinya, 2012;Kameya et al, 2014). In a previous laboratory experiment, more than 80% of chemicals examined had a recovery ratio of 50 -140%.…”