Geosciences Labs

To achieve ultra-high-precision isotopic ratio measurements of radiogenic and stable isotopes (e.g., Sr, Nd, Os), Thermal Ionization Mass Spectrometer (TIMS) is used.

The Thermal Ionization Mass Spectrometer (TIMS) is a high-precision analytical instrument designed for accurate determination of isotopic ratios in geological and environmental samples. It is widely used in geochronology, geochemistry, oceanography, and isotope hydrology to investigate diverse Earth system processes. In TIMS, chemically purified samples are loaded onto ultra-clean metal filaments (typically Ta, Re, Pt, W) and introduced into the mass spectrometer and evacuated. Controlled thermal heating of the filament induces ionization of the target elements. The generated ions are accelerated and separated according to their mass-to-charge (m/z) ratios, and their abundances are simultaneously measured using high-sensitivity detectors, enabling extremely precise and reproducible isotope ratio measurements. At PRL, TIMS has been extensively applied to address key questions in Earth sciences, including Re-Os geochronology, ocean circulation studies, erosion and chemical weathering processes, sedimentary provenance, archaeology, crustal evolution, and crust–mantle interactions, contributing significantly to fundamental and applied geoscience research.

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Several peer-reviewed research articles have been published till date using the TIMS data highlighting its significant contribution to high-impact scientific research.

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To provide high-precision measurements of water and water vapor stable isotopes (δ¹⁸O, δD) using laser-based Picarro CRDS and LGR analyzers, including triple oxygen isotope (Δ¹⁷O) analysis in water, supporting hydrological cycle studies, moisture source tracing, paleoclimate reconstruction, and atmospheric process investigations.

This laboratory is equipped with advanced laser-based analyzers, including Picarro CRDS and LGR systems, for high-precision measurements of water and water vapor isotopes. The instruments determine δ¹⁸O and δD in liquid water and atmospheric moisture with excellent accuracy, repeatability and rapid throughput. The facility also supports triple oxygen isotope (Δ¹⁷O) analysis in water and water vapor, enabling detailed investigations of evaporation, condensation, evatranspiration and moisture source processes. The analyzers operate on cavity ring-down (CRDS) and off-axis integrated cavity output (OA-ICOS) spectroscopy principles. Automated sample injection systems and vaporization modules allow efficient processing of diverse samples, including precipitation, river and groundwater, soil water, plant water, and atmospheric vapor. Calibration against international standards ensures data quality and inter-laboratory comparability. This facility plays a crucial role in hydrology, monsoon dynamics, paleoclimate reconstruction, ecohydrology, and atmospheric research by providing robust isotopic constraints on water cycle processes across spatial and temporal scales.

Several peer-reviewed research articles have been published till date using data generated by this facility, highlighting its significant contribution to high-impact scientific research.

The HR-ICP-MS geochemistry and cosmochemistry laboratory provides unparalleled capabilities and experience for isotope analysis of geological and extraterrestrial materials, making it a vital resource for researchers in these fields.

The Element XR instrument's exceptional sensitivity, which enables it to measure trace element concentrations at parts per billion or even parts per trillion, makes it an invaluable tool for geochemists seeking to understand more about the composition and evolution of our planet. The results of these studies contribute to our understanding of the fundamental processes that have shaped our planet and the universe. The lab's present focus is on the isotopic analysis of elements such as Si, Fe, Cr, Pb, Sr, Mo, and Nd, which are commonly used to investigate the age, origin, and evolution of geological and planetary materials. Important insights into several Earthly processes, including as sedimentary provenance, metamorphism, magma genesis, and core formation, can be gained from the isotopic composition data. We are also expanding the scope of our research to encompass isotopes of additional geochemical tracers.

To deliver high-precision and continuous measurements of CO₂ and CH₄ concentrations and their stable carbon isotope ratios in ambient air, soil air, soil-emitted fluxes, dissolved in water, and water-surface emissions using Picarro CRDS, supporting greenhouse gas source - sink quantification, carbon cycling, ecosystem exchange and climate change research.

The Picarro Cavity Ring-Down Spectroscopy (CRDS) system at PRL is a laser-based instrument designed for high-precision measurement of greenhouse gases, particularly concentrations and stable carbon isotope ratios (δ¹³C) of CO₂ and CH₄. Operating on the principle of cavity ring-down spectroscopy, it determines gas concentrations by measuring the decay rate of laser light within a high-finesse optical cavity, providing exceptional sensitivity, stability, and precision. In addition, the system provides δ¹³C values of CO₂ and CH₄. The analyzer supports continuous, real-time monitoring of gases in ambient air, soil air, soil-emitted fluxes, dissolved gases in water, and water-surface emissions. With low detection limits, high temporal resolution, and calibration against certified reference gases, the instrument ensures accurate and reproducible data. The Picarro CRDS facility thus plays a key role in advancing research on carbon cycling, greenhouse gas dynamics, ecosystem exchange, hydrological interactions and climate change.

Several peer-reviewed research articles have been published till date using data generated by this facility, highlighting its significant contribution to high-impact scientific research.

To provide high-precision stable isotope analyses of atmospheric gases and water (H₂, CO₂, O₂, N₂, N₂O), nitrate, aerosols, soils, sediments, speleothems, carbonates, and foraminifera, including advanced measurements of triple oxygen isotopes (CO₂, O₂, H₂O, carbonates) and carbonate/CO₂ clumped isotopes for environmental, climatic and biogeochemical research applications.

The Stable Isotope Ratio Mass Spectrometry (IRMS) Laboratory at PRL is a state-of-the-art facility dedicated to high-precision measurements of stable isotopes in gases, waters and solid materials for applications in climate, environmental and biogeochemical research. The laboratory houses five advanced IRMS systems, including a MAT 253 and four Delta V Plus mass spectrometers, coupled with automated peripheral devices such as the Kiel Carbonate Device, GasBench, Elemental Analyser and Nitrate Isotope Measurement System. The facility supports isotopic measurements of H₂O, H₂O vapour, CO₂, O₂, N₂, and N₂O in atmospheric samples, as well as nitrate, aerosols, soils, sediments, speleothems, carbonates and foraminifera. It also enables advanced analyses such as triple oxygen isotopes in CO₂, O₂, carbonates and silicates, and clumped isotope measurements in carbonates and CO₂. With stringent quality control protocols and international standards calibration, the laboratory provides high-accuracy and reproducible data, supporting national and international research programs in paleoclimate reconstruction, hydrology, carbon cycle studies and Earth system science.

Several hundreds of peer-reviewed research articles have been published till date using data generated by the PRL IRMS facility, highlighting its significant contribution to high-impact scientific research.

To measure trace and major element composition of aqueous samples.

Trace element and major element concentrations in water samples are measured using emission spectroscopy. The samples analysed involve river water, ground water and aqueous samples prepared from solids samples such as aerosol, soil, sediments and rock as a part of ongoing research programs of Geochemistry, Aerosol chemistry, biogeochemistry, paleoceanography and paleoclimate.  

Inductively Coupled Plasma – Optical Emission Spectrometer (ICP-OES) (Thermofisher Scientific iCap 7000 Series)

To measure major ion composition of aqueous samples.

Major ion concentrations in water samples are measured using ion exchange chromatography separation and conductivity detection method. The samples analysed involve rain water, river water, ground water and aqueous samples prepared from solids such as aerosol and soil as a part of ongoing research programs of Hydrology, Geochemistry, Aerosol chemistry and biogeochemistry. 

Ion Chromatograph (Thermofisher Scientific Dionex-ICS 5000)

To convert diverse carbon-bearing materials, including soils, sediments, charcoal, fossil shells,  tooth enamel, wood, speleothems, foraminifera and water samples, into high-purity graphite targets for precise AMS ¹⁴C dating, ensuring reliable age determination for archaeological, paleoenvironmental, hydrological and Earth system science investigations.

The PRL Graphitization Facility is a dedicated laboratory that prepares high-purity graphite targets for Accelerator Mass Spectrometry (AMS) radiocarbon (¹⁴C) dating. The laboratory processes a wide range of carbon-bearing materials, including soil and sediment organic matter, charcoal, wood, fossil shells, tooth enamel, speleothems, foraminifera, and dissolved inorganic carbon from water samples. Samples undergo rigorous chemical pretreatment to remove contaminants, followed by controlled combustion or acid hydrolysis to convert carbon to CO₂. The purified CO₂ is then reduced to graphite using both hydrogen and Zn-Fe reduction techniques. Strict blank control, standardized protocols and quality assurance procedures ensure minimal background contamination and high reproducibility.

In addition, the facility features an in-house developed high-precision graphitization system designed specifically for gaseous samples such as CO₂, CO, and CH₄. This customized setup enables efficient conversion of trace-level gases into graphite targets with excellent yield and low procedural blanks, supporting atmospheric, hydrological, and carbon cycle studies. The facility thus plays a critical role in ensuring reliable and accurate ¹⁴C measurements at PRL.

Several peer-reviewed research articles have been published using data generated by the PRL Graphitization-AMS facility, highlighting its significant contribution to high-impact scientific research.

Picophytoplankton distribution and their role in the biogeochemical cycling in the ocean

The sorter flow cytometer, a fluorescence-activated cell-sorting system, separates a mixed microbial community into up to four containers, one cell at a time, based on each cell’s unique light-scattering and fluorescence properties. This facility is used to analyze marine microbial phytoplankton and bacterial cells with high precision.

Nazirahmed, S., D. Sahoo, H. Saxena, and A. Singh (2025), Picophytoplankton Distribution and Their Contribution to Particulate Organic Carbon in the Northern Indian Ocean. Journal of Geophysical Research: Biogeosciences, 130, e2025JG009023.

Nazirahmed, S., P. Rahi, H. Saxena, A. Singh, and R. Panchal (2025), High prokaryotic diversity in the oxygen minimum zone of the Bay of Bengal: implications for nutrient cycling. Aquatic Microbial Ecology, 91, 31-51

To provide high-precision measurements of cosmogenic radioisotopes (¹⁴C, ¹⁰Be and ²⁶Al). It is routinely used for ¹⁴C dating of archaeological and environmental materials, and ¹⁰Be - ²⁶Al analyses for quantifying erosion rates, catchment dynamics, burial history, and surface exposure ages, thereby advancing research in geomorphology, paleoclimate, hydrology, and Earth surface processes.

The 1 MV Accelerator Mass Spectrometry (AMS) Laboratory at the Physical Research Laboratory is a state-of-the-art facility dedicated to high-precision measurement of cosmogenic radionuclides for Earth, environmental and archaeological research. The facility is designed for routine analysis of Radiocarbon (¹⁴C), Beryllium-10 (¹⁰Be), and Aluminium-26 (²⁶Al), supporting applications in geochronology, geomorphology, hydrology, paleoclimate, and Quaternary science. The laboratory includes dedicated sample preparation units for graphite production, chemical separation of Be and Al, and clean lab infrastructure to ensure ultra-low background measurements. The AMS facility provides radiocarbon dating of archaeological remains, soils, sediments, and groundwater, as well as in situ and meteoric ¹⁰Be and ²⁶Al measurements for surface exposure dating, erosion rate estimation, burial dating, and catchment-scale process studies. The laboratory serves as a national resource, fostering interdisciplinary research and collaborations across India and internationally.

More than 80 peer-reviewed research articles have been published till the end of 2025 using data generated by the PRL AMS facility, highlighting its significant contribution to high-impact scientific research.

  Characterization of Secondary Aerosols on various time scales

· Identifying the sources and processes affecting aerosol composition using Isotopes

·       Fate of Environmental Microplastics/Nanoplastics

·       Investigating the Aerosol Oxidative Potential

·       Characterization of Brown Carbon aerosols

· Investigating Upper Troposphere Lower Stratosphere (UTLS) chemistry

We investigate the sources and processes affecting concentrations, composition, and characteristics of ambient aerosols over different parts of India and surrounding oceans, and how they relate to air quality, human health, climate change and aquatic biogeochemistry. We are equipped with various sophisticated offline and online instruments to achieve the said objectives.

High Resolution Time-of-Flight Aerosol Mass Spec (HR-ToF-AMS)

Aethalometer

Scanning Mobility Particle Sizer (SMPS)

Light weight Aerosol Sampler

Particle-into-Liquid Sampler (PILS)

Total Organic Carbon (TOC) Analyser

Ion Chromatograph

EC-OC Analyzer

Our pioneer work on aerosol ‘Oxidative Potential (OP)’ in India revealed that biomass burning (BB) derived species have highest OP among all sources, and aerosol OP increases by atmospheric processing during transport. We used ¹⁴C and ¹³C to assess the contribution of fossil vs non-fossil sources to carbonaceous aerosols and their characteristics. Using an assembled unique analytical system, we divulged that brown carbon (BrC) aerosol is combinations of numerous chromophores including HULIS and nitro-aromatics with their absorbing characteristics changing diurnally. Using δ¹⁵N-NH₄⁺, δ¹⁵N-NO₃^-, and δ¹⁸O-NO₃^-, we are investigating the sources and characteristics of particulate reactive nitrogen species. Our pilot laboratory study revealed that photo-degradation of microplastics release CO₂ and CH₄ with very low δ¹³C values and their concentrations increase with reduction in plastics size.