Evaluation of direct reading photoionization detector performance under various operational parameters Khoshakhlagh, Amir Hossein Carrasco Marín, Francisco Toluene Temperatures Humidity Adsorption Chromatography Gas regression analysis Research Design The authors would like to thank Tehran University of Medical Sciences and Iran National Science Foundation (INSF) , for supporting this project. This study was supported by Tehran University of Medical Sciences under Ph.D. thesis scheme (Number: 9421138001) and the INSF. The funding body played no role in the design of the study, collection and analysis of data, interpreting results or writing the manuscript or decision to submit the manuscript for publication. The content of this publication is only the responsibility of the authors. Background: A hand-held portable direct-reading monitor, including photoionization detector (PID) is renowned for its good sensitivity, considerable dynamic range, and nondestructive vapor detection ability in comparison to the tardy response of the PID in gas chromatography (GC), which its application has been restricted. In this study, the performance of a PID system (MultiRAE Lite) was evaluated as a replacement of GC in the measurement of toluene in a dynamic adsorption system. Methods: The test was done at different relative humidity levels (30%, 50%, and 80%), temperatures (21, 30, 40°C), and toluene concentrations (20, 100, 200, and 400 ppm). Results: The PID achieved 48% of all measurements meeting the comparison criterion. The results showed that the performance of the PID could be altered by the variables. The best performance of the PID was at temperature of 21°C, the relative humidity of 50%, and concentration of 200 ppm with the percentage of readings achieving the criterion of comparison to 58%, 54%, and 52%, respectively. The averages of the PID readings (mean ± SD at 200 ppm= 207.9 ± 8.7) were higher than the reference method measurements averages (mean ± SD at 200 ppm= 203.5 ± 5.8). The regression analysis of the toluene results from the PID and the reference method results indicated that the measurements were significantly correlated (r2 = 0.93). Conclusion: According to the results, the device response is linear. Therefore, the findings are acceptable in adsorption studies. In this way, the measurement of the sample concentration should be performed using the same instrument before and after the reactor in order to calculate the adsorption efficiency. 2021-11-23T08:23:36Z 2021-11-23T08:23:36Z 2021-05-14 journal article Khoshakhlagh A H... [et al.]. Evaluation of direct reading photoionization detector performance under various operational parameters. Environ. health eng. manag.. 2021; 8 (2) :123-128. [10.34172/EHEM.2021.15] http://hdl.handle.net/10481/71677 10.34172/EHEM.2021.15 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Kerman University of Medical Sciences