Validation of Passive Samplers for Accurate, Long-Term, Time-Weighted Air Concentrations in Manhole Environments with Potentially Time-Variable Volatile Organic Air Contaminant Concentrations
Abstract
ESTCP projects ER-201505 and ER-201501 suggested manhole air sampling be part of VI assessment but indicated that contaminant concentrations within manholes can be temporally variable and suggested long-term sampling of that environment. Passive samplers offer a cost-effective method for collecting samples and ER-201501 studies indicated the sampler can provide accurate, long-term, time-weighted concentrations for indoor air environments with calibration and validation of the sampler used. The objective of this demonstration was to validate the use of the passive sampler for accurate assessment of volatile organic air contaminant concentrations in manhole environments where temperature, relative humidity, and contaminant concentration can vary with time. Performance was tested against the traditional TO-17 type thermal desorption tube (TD tube) active sampler in two, back-to-back, 8-day sampling events using 5 manholes with a history of contaminant in the vapor phase. Results using the Bland and Altman assessment to determine if the passive sampler was a suitable replacement for the active sampler suggested it was not. However, that method may not have been reasonable given the /-30 range that is considered acceptable for analytical laboratories. Alternatively, regression analysis indicated the passive sampler was fairly precise, yet lacked accuracy for many analytes. This suggested the sampler could be a viable sampling tool with proper calibration and validation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 02, 2022
- Accession Number
- AD1216403
Entities
People
- Paul Dahlen
- Paul Johnson
Organizations
- Arizona State University
- Colorado School of Mines