The Isotope Ratio Mass Spectrometer in the Stable Isotope Laboratory of PPOD, Bangalore is of the make SerCon Ltd., U.K. and model GEO 20-20.
This instrument consists of (1) an Inlet System, which is of two types Dual-Inlet and Continuous
(2) an Ion Source, which is an electron impact ion production system using a W filament,
(3) a Mass Analyzer which uses a Magnetic Sector for mass separation and (4) a Collector Array with a triple Faraday cup assembly.
The instrument is attached online with four different peripheral systems for sample preparation and handling viz.,
- CAPS – Carbonate Automated Preparation System
- WES – Water Equilibration System
- ANCA-GSL – Automated Nitrogen Carbon Analysis for Gases, Solids and
- WECS – Water Equilibration and Carbonate-Acid reaction System.
The entire system along with its peripherals is kept evacuated using pumping system consisting of several Rotary and Turbo Molecular Pumps.
Standard Operating Procedure
Separation of pure fractions of carbonates and sulphides from rock/fossil/ore fragments through magnetic/ isodynamic separator and hand picking under binocular microscopes.
Determination of "Clttc and "O/tuO isotope ratios of carbonates from carbonatites, sedimentary carbonates, and calcareous fossils for paleoclimatic and paleogeographical
interpretation and sou rce characte ristics of ca rbon ( mantle/sed i menta ry/ biogen ic)
Determination of 'oS/"S isotope ratios of sulphide and barium sulphate for volcanogenic,
hydrothermal or biogenic modelling of ore deposits
Additional Director General
National Mission Head-IV
Geological Survey of India
15 A & B Kyd Street