Analysis of Polycyclic Aromatic Hydrocarbons in Polyurethane Foam (PUF) and Diethylene Glycol/Water Samples Using Automated Pressurized Liquid Extraction, Cleanup and Solid Phase Extraction

Air Monitoring, Methods, and Technology
Oral Presentation

Prepared by R. Addink, T. Hall
Fluid Management Systems, 900 Technology Park Dr, Billerica, Massachusetts, 01821, United States


Contact Information: [email protected]; 617-393-2396

ABSTRACT

PAHs are measured worldwide in air, sediment, soil, and water. Industrial sources include coal gasification, municipal solid waste incineration and petroleum refining.

In waste incineration, PAHs are Products of Incomplete Combustion found in emissions, dust, fly ash, and bottom ash. PAHs are subject to regulation and monitoring in many countries due to their potential health risks.

We developed an automated method for the analysis of polycyclic aromatic hydrocarbons (PAHs) collected during the sampling of incinerator stacks. This method employs Polyurethane Foam (PUF) and diethylene glycol/water mixtures to effectively trap PAHs that are not captured by PUFs.

Plugs of PUF were spiked with native PAHs standards, combined with inert filling material (Ottawa Sand), placed in stainless steel extraction cells, and heated/extracted using automated Pressurized Liquid Extraction (PLE). The process was carried out at 100 oC for 20 min at 1500 psi with a 50/50 dichloromethane/hexane mix.

After automated extract concentration (using a dry metal heating block) samples underwent cleanup over single 6g neutral silica columns using an automated system (multi-pump with six parallel column positions). Elution was done with consecutive dichloromethane and hexane.

Known amounts of native PAHs were added to diethylene glycol/water and processed using automated solid-phase extraction (SPE) with C-18 cartridges. After cartridge conditioning (DCM, methanol, water), sample loading, automated bottle rinse, and drying, collection was carried out with repeated elution of DCM (time for soaking).

A single quad GC/MS was used for the analysis. Native PAHs recoveries from PUF were 70-90% and from automated SPE 100-110%.

This work shows a fully automated workflow comprising extraction (PLE, SPE) and cleanup resulting in excellent recoveries. Labor and processing times are significantly reduced, while delivering consistent and reliable results.