Extractable Petroleum Hydrocarbons (EPH) - Lot to Lot Reproducibility of Resprep EPH Cartridges

 

As previously discussed in my last blog, “Extractable Petroleum Hydrocarbons (EPH) Method – Why it is important?”, Restek’s Resprep EPH Fractionation SPE Cartridges (cat # 25859) provide method-specific performance for EPH analysis of soil and water samples through complete separation of aliphatic and aromatic compounds into distinct fractions, while providing extractable background levels guaranteed to fall under the strict reporting limits of Massachusetts and New Jersey EPH methods. Restek’s newly optimized silica gel cartridges have superior lot-to- lot reproducibility and storage stability ensured by rigorous QC testing and moisture-resistant packaging.

The fractionation step of the silica gel cleanup is a sensitive and critical procedure. Small changes in the elution volumes, analytical equipment, or analytical techniques can impact the proportion of hydrocarbons separated into their respective fractions. According to Massachusetts EPA, “it is recommended that a Fractionation Check Solution be analyzed for each new lot of silica gel/cartridge, to reestablish the optimum volume of hexane elution.” [1] For lab, this can be very time consuming, as well as, a very tedious process. Resprep EPH SPE cartridges offer consistent and complete separation between aliphatic and aromatic compounds from one lot to the next. Figure 1 shows a representative subset of compounds (40 + compounds were analyzed in total) to clearly illustrate the separation between fractions and lack of breakthrough in every lot produced. Restek manufactures quality into each EPH cartridge by closely monitoring the silica gel used and tightly controlling cartridge weight to ensure consistent performance with each cartridge through a lot, as well as, between lots.

 

[1] Massachusetts Department of Environmental Protection, Method For The Determinations of Extractable Petroleum Hydrocarbons (EPH). May 2004. Revision 1.1