Solid-Phase Extraction of Polycyclic Aromatic Hydrocarbons from Groundwater: Using Reduced Sample Volume and Non-Chlorinated Solvents

Innovative Solutions for Reducing Methylene Chloride
Poster Presentation

Presented by D. Shelly
Prepared by A. Cocozza
UCT, 2731 Bartram Rd, Bristol, Pennsylvania, 19007, United States


Contact Information: [email protected]; 215-781-9255

ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs) are toxic organic pollutants formed during the incomplete combustion of organic materials, with high-molecular-weight PAHs posing significant risks to human health and the environment. Accurate and efficient monitoring of these compounds in groundwater is therefore essential. A validated solid-phase extraction (SPE) method coupled with GC-MS in SIM mode was developed for the analysis of 16 PAHs and one methylated PAH, optimized for small sample volumes (100 mL) and environmentally friendly, non-chlorinated extraction solvents (hexane/acetone). The performance of two sorbent chemistries, C18 and highly cross-linked styrene-divinylbenzene (HLD), was evaluated. The results demonstrated a rapid, sensitive, and environmentally conscious approach for detecting PAHs in groundwater.
An Initial Demonstration of Proficiency (IDP) study was performed to assess method performance on a clean matrix (reagent water). For precision and accuracy C18 (91–104% with RSDs ≤ 7%) and HLD (88–107% with RSDs ≤ 6%) exhibited good recoveries for all tested PAHs. Both sorbents showed reliable recoveries in simulated groundwater, with C18 ranging 62–112% (except acenaphthylene, 41%; RSD ≤ 24%) and HLD ranging 52–100% (RSD ≤ 7%). Acenaphthylene and anthracene exhibited some recovery losses and increased variability in both sorbents, however, all results remained within EPA quality control limits. This study demonstrates that SPE efficiently recovers PAHs from small-volume groundwater samples, minimizing solvent use and hands-on time, while employing a non-chlorinated solvent approach, providing a practical and environmentally friendly alternative to traditional liquid–liquid extraction.