Sensing Characteristics of a Real-time Monitor Using a Photoionization Detector on Organic Solvent Vapors

Abstract

: Measurements of organic solvents in the work environment are carried out by either direct sampling using plastic bags/gas chromatography, solid sorbent adsorption using charcoal tubes/gas chromatography, or by a direct reading method using detector tubes. However, these methods cannot always measure the work environment accurately because the concentration of hazardous materials changes from time to time, and from space to space. In this study, the sensor characteristics of a real time monitor using a photoionization detector that can monitor vapor concentration continuously were investigated for 52 organic solvent vapors that are required to be measured in the work environment by the Ordinance of Organic Solvent Poisoning Prevention in Japan. The sensitivity of the monitor was high for the solvents with low ionization potential. However, the sensitivity for the solvents with high ionization potential was low, and the sensor could not detected 7 solvents. Calibration of the sensor using a standard gas was desirable before being used for measurement because the sensitivity of the sensor was variable.

Comparison of sensor characteristics of three real‐time monitors for organic vapors

“…Therefore, it is reasonable that methanol, which could not be detected by the other two monitors, can be detected by this monitor with a linear response. In addition to semiconductor sensors, we also previously confirmed that the PID sensor also exhibited temporary deterioration when we used another monitor 4) . Therefore, when we use such real-time monitors for determination of organic vapors, calibration should be conduct- ed in advance of measurement.…”

“…We have been studying the sensor characteristics of several real-time monitors for organic vapors or volatile organic compounds 3−6) . First, we tested a monitor with a photo ionization detector (PID) 4) for 52 organic solvents. Although this monitor had high sensitivity and a linear response was obtained for many solvents, it showed low or no response for some solvents with a high ionization potential.…”

The Past, Present and Future in Tube- and Paper-Based Colorimetric Gas Detectors

“…This feature is an advantage when developing a new gas detector. In addition, colorimetric gas detectors currently commercially available can measure more than 300 types of gases [80][81][82][83][84][85][86][87][88][89][90].…”