Making a case for regenerating and recycling gas chromatography liners in industrial wastewater screening for organic pollutants

Poster-Other
Poster Presentation

Prepared by O. Otim
Environmental Monitoring Division, City of Los Angeles, 12000 Vista Del Mar, Playa del Rey, California, 90293, United States


Contact Information: ochan.otim@lacity.org; (310)6485835


ABSTRACT

An environmental laboratory can save on GC inlet liners by regenerating the many liners usually discarded ostensibly to reduce dead time after every industrial wastewater extracts batch screening for semi-volatile organic pollutants. This paper presents a simple and environmentally friendly regeneration method for these liners together with a novel approach for expeditiously assessing the efficacy of regeneration. The assessment involves plotting the relative percent deviations of replicate measurements of spiked levels of the individual organic pollutants against their percent recovery. The level of regeneration by this protocol is shown to meet and exceed data quality objectives required for 61 priority pollutants (the pollutants included phenols, phthalic acid esters, polynuclear aromatic hydrocarbons, and low boiling point organic compounds). The spike recoveries of these 61 priority pollutants ranging from 89% to 107% were comparable to recoveries obtained in new liners. We also observed that measurements obtained in regenerated liners were more precise that those from new ones. On average though, measurements obtained in regenerated liners were 3.1 ug/ L below measurements obtained in new liners. This 3.1 ug/ L inherent bias is, however, lower than the 10 ug/ L reporting limit in industrial wastewater extracts analysis for semi-volatile organic pollutants and should not hamper the acceptance of regenerated liners as substitutes for new liners. A re-regeneration of 11 of those same regenerated liners after a second use produced the same level of performance.