What is the preferred sample container for GRO groundwater samples?

The preferred sample container for Gasoline Range Organics (GRO) groundwater samples is a 40 ml, Teflon-lined volatile organic analysis (VOA) vial that is preserved with hydrochloric acid (HCl). This choice is optimal for several reasons.

Firstly, Teflon-lined containers minimize the risk of compound adsorption onto the container walls, which can lead to sample loss or alteration of the sample's actual concentration. This integrity is crucial for accurate analysis, especially for volatile compounds that are present in gasoline and other petroleum products.

Preserving the sample with hydrochloric acid serves to lower the pH of the sample, which helps stabilize certain analytes that may otherwise degrade or change chemically over time. Maintaining the correct pH is critical in ensuring that the organic compounds of interest remain in their stable forms until analysis can be performed.

Overall, using a Teflon-lined vial with HCl preservation effectively maintains the sample's integrity, reducing the potential for loss of analytes and ensuring accurate results when the samples are analyzed for GROs.