RSKSOP-175 – Dissolved Gases in Water

Natural attenuation, or intrinsic remediation, is increasingly becoming the remediation technique of choice.  This technique allows for naturally occurring microbial activity to metabolize the contaminants of concern.  The suitability of a site or progress of the remediation is evaluated partly on results of the analysis of groundwater samples for dissolved gases such as methane, ethane, or ethylene.

Air Technology provides this unique analytical procedure.  The procedure requires that the sample be collected in an airtight container (typically a 40-mL VOA vial) preserved to pH 2 (unless carbon dioxide needs to be determined).  The laboratory generates a headspace in the sample by replacing a portion of the water with helium.  After thorough agitation and equilibration, an aliquot of the headspace is analyzed via GC/FID.  Henry’s Law stipulates that, in a closed system in equilibrium, the concentration of a gas in the headspace can be used to determine the concentration of the gas dissolved in water. https://imamiddleeast.org/zoloft-online/

Quality control includes the analysis of a method blank, sample duplicates (when available), and a laboratory control sample.  USEPA Procedure RSKSOP-175 (Robert S. Kerr Standard Operating Procedure) is used as guidance.

RSK175 table lists the analytes and reporting limits (RLs) for method RSKSOP-175 for standard analysis. https://imamiddleeast.org/vermox-online/