Extraction of Semivolatile Organics in Water According to EPA 8270E Using Solid-Phase Extraction (EPA 3535) and Hydrogen as Carrier Gas for GC/MS Analysis

Automation & Innovation for Sample Preparation
Poster Presentation

Prepared by A. Cocozza
UCT, 2731 Bartram Rd, Bristol, PA, 19007, United States


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

ABSTRACT

EPA Method 8270E represents the latest update in the EPA 8000 series for a wide range of semi-volatile organic compounds. Traditionally, water samples are extracted by liquid-liquid (EPA 3520) or separatory funnel (EPA 3510) extraction, which required the use of large volumes of methylene chloride (DCM) to adequately extract base/neutral and acidic fractions from the sample. However, recent EPA regulations on DCM highlight the need to reduce the use of this hazardous solvent in laboratories. EPA 8270E allows solid-phase extraction (SPE) as an alternative sample preparation method. By switching to SPE, laboratories can significantly reduce solvent consumption, decrease environmental impact, and improve laboratory safety by reducing exposure to hazardous chemicals.
United Chemical Technology’s (UCT) proprietary 8270 sorbent was specifically developed to selectively isolate acidic, basic, and neutral compounds, and is used in combination with an activated carbon cartridge to enhance the retention of highly polar analytes such as 1,4-dioxane. A 1-liter water sample is passed through this cartridge combination, eluted into separate fractions, and subsequently combined and concentrated for analysis. Additionally, a multi-port SPE glass block manifold allows for the simultaneous extraction of multiple samples, significantly enhancing laboratory throughput. This research demonstrates that the developed SPE methodology, using a specific set of cartridges, enables the detection of at least 132 analytes at minimum reporting levels of 10 µg/L or lower, covering compounds on the EPA Priority Pollutant List (PPL), the RCRA Appendix IX list, and the Superfund Analytical Methods target list (SFAM01.1). Furthermore, using hydrogen as carrier gas offers a cost-effective alternative to helium, which has faced supply constraints, while maintaining reliable performance for SVOC analysis.
Performance evaluation showed that 81 of the 133 compounds analyzed had acceptable precision and recovery at a lower limit of quantification (LLOQ) of 1ug/L. Seven replicates spiked at 1ug/L were performed over three days to determine the limit of detection (LOD) for these compounds. Additionally, seven replicates spiked at 5/10 µg/L (for Benzidine, 3’3-Dichlorobenzidine, Methapyrilene, and Benzoic Acid) were performed over three days to determine the LOD for the remaining compounds. All but one of the 133 compounds achieved acceptable precision and recovery at a lower limit of quantification (LLOQ) of 5 µg/L (10 µg/L for Benzidine, 3’3-Dichlorobenzidine, Methapyrilene, and Benzoic Acid). The compound 1,4-Phenylenediamine did not meet the recovery criteria in LLOQ studies, possibly due to degradation from interaction with other analytes in the quality control samples. An initial demonstration of performance (IDP) was conducted by extracting four replicates at 20 µg/L, with recoveries evaluated to ensure compliance with the performance-based method’s acceptable range of 50–150%, as outlined in Section 1.1. While 1,4-Phenylenediamine (34%) and Hexachloropropene (41%) fell outside this range, these compounds are known to present challenges or lack historical data for aqueous extractions.
This research validates a more sustainable and environmentally friendly approach to conducting EPA Method 8270E by reducing solvent waste and exposure, supporting high-throughput workflows, and meeting EPA quality control protocols for comprehensive SVOC analysis.