Gaschromatography Laboratory of the Roma1 Section is able to carry out quantitative chemical analysis of the gaseous species sampled during the soil gas surveys, of the bubbling phase from pools or aquifers, of the dissolved gasses in the waters. Laboratory is equipped with the following instruments: Agilent 4900 microGC and Agilent 990 microGC. These instruments are equipped with thermal conductivity detector (TCD) and a gas carrier (e.g., Argon) and allow a complete analysis to be carried out in 5 minutes. By means the two gas chromatographs present in the laboratory it is possible to carry out the chemical analyzes of the following gaseous components: Helium (He), Neon (Ne), Hydrogen (H2), Carbon Oxide (CO), Nitrogen (N2), Oxygen (O2), Air, Methane (CH4), Carbon Dioxide (CO2), Acetylene (C2H2), Ethane (C2H6), Ethylene (C2H4) and Acid Sulfuric (H2S).
Geochemical data
Alessandra Sciarra - alessandra.sciarra@ingv.it - ORCID: https://orcid.org/0000-0003-3767-3105
Hands-on access
The Agilent 990 microGC, a very delicate and highly accurate instrument, is equipped with a thermal conductivity detector (TCD). This detector corresponds to differences in thermal conductivity between the carrier gas and the components of the sample to be analyzed. In a TCD the signal generated by the transit of the carrier gas is compared with an equivalent gas. The transit of the sample components inside the detector causes an imbalance of the signal proportional to its concentration. Inside it has two different types of columns, Molsieve 5Å column having a length of 20 m, and PoraPlot Q (PPU) column with a length of 10 m. The concentration of the samples is established on the basis of the calibration curve (Figure 3) and the previously constructed method, by means of standard gases with concentrations varying between a few ppm and 100% by volume.
Alessandra Sciarra - alessandra.sciarra@ingv.it - ORCID: https://orcid.org/0000-0003-3767-3105
INGV - Sezione Roma 1
Via di Vigna Murata, 605, 00143 - Roma
Via di Vigna Murata, 605, 00143 - Roma