National Centre for Earth Science Studies

Environmental Monitoring, Pollution Assessment and Mitigation Laboratory

A suitable and safe natural environment is a pre-requisite for healthy and quality of habitat life. It is possible only by environmental monitoring, pollution assessment and suitable mitigation strategies including observations and characterization of the quality of the rivers, springs, estuaries, soils, atmosphere and specific settings. Environmental pollution assessment and mitigation laboratory is integral part of the Central Chemical Laboratory (CCL) at NCESS by providing research and development methodologies/facilities which involves laboratory testing, monitoring, assessment with mitigation plans and consultancy services to a wide range of industrial companies, environmental consultants and government authorities. Environmental laboratory is equipped with qualified human resources, modern facilities and sophisticated instruments such as gas chromatography with fid detector (GC), gas chromatography coupled with mass spectrometry (GC-MS/MS), Surface area analyser (Micromeritics), liquid chromatography coupled with mass spectrometry (LC-MS/MS), Fourier Transform Infrared Spectrophotometer (FT-IR), microwave plasma atomic emission spectrometry (MP-AES), Spectrofluorometer (Fluorescence) and dedicated microbiology lab. This laboratory is capable of performing a wide range of analysis on drinking water, industrial and domestic wastewater, surface and ground water, polluted soils/sediments, trace organic pollutants in water, soil/sediments, construction materials, sludge, etc. including air quality monitoring. And also, the laboratory has involved in developing materials for mitigating the metal pollutants in water/soil and high concentration of nutrients (nitrate, phosphate) in agricultural soils and waters based on surface chemistry principles. List of instruments/facilities available with geochemical analytical laboratory and their brief details are provided below.

Instruments/Facilities available with Hydrochemical Analytical Laboratory:

1. Gas Chromatography with FID Detector (GC)
2. Gas Chromatography Coupled with Mass Spectrometry (GC-MS/MS)
3. Surface Area Analyser
4. Liquid Chromatography Coupled with Mass Spectrometry (LC-MS/MS)
5. Fourier Transform Infrared Spectrometer (FT-IR)
6. Spectrofluorometer (Fluorescence)

Gas Chromatography with FID Detector
Make: Perkin Elmer; Model: Clarus-580

Gas chromatography is a tool involved in the analytical separation technique and is useful to identify and quantify the volatile substances in the gas phase only. In gas chromatography, the components of a sample (gaseous) are dissolved in a solvent and vaporized in order to separate the analytes by distributing the sample between two phases; a stationary phase and a mobile phase. The mobile phase is a chemically inert gas that serves to carry the molecules of the analyte through the heated column. The stationary phase is either a solid adsorbent or a liquid on an inert support. The PerkinElmer Clarus 580 Gas Chromatograph (GC) is a fully automated gas chromatograph and the system offers the capabilities required for analyzing the large numbers of gaseous samples as part of research or the routine analyses. All instrument functions are set up and monitored through a touch screen with an intuitive graphical user interface that includes a real-time chromatogram display.

Gas Chromatography Coupled with Mass Spectrometry (GC-MS/MS)
Make: Thermo Fischer; Model: Trace 1310-TSQ Duo

Gas Chromatography-Mass Spectrometry (GC-MS/MS) is a combination of two different analytical techniques, Gas Chromatography (GC) and Mass Spectrometry (MS) and is used to analyse complex organic, biochemical mixtures and permanent gases, sometimes it’s referred as GC-QQQ system. The GC-MS/MS system consists of two main components, Gas Chromatography (GC) portion which separates different compounds in the sample into “pulses” of pure chemicals based on their volatility (volatile and semi-volatile compounds) with great resolution, by flowing an inert gas (mobile phase), which carries the sample, through a stationary phase fixed in the column, whereas the Mass Spectrometry (MS) portion provides detailed structural information as the pure compounds exits the chromatographic column and can exactly be identified and quantified (with reference to the standard concentration) according their mass-to-charge ratio (m/z) hence, the combination of GC-MS is unique in identifying the compound with very high sensitivity and selectivity. And the MS/MS system involves the mass spectrometric analysis of the precursor ions which are obtained by GC-MS system, this future generally useful in detection and potential identification of chemicals in the presence of other chemicals (in a complex mixture) with high sensitivity. The GC-MS/MS system from Thermo scientific company of model number Trace-1310 coupled with TSQ Duo with automatic sampler and inbuilt software for communicating with system. This instrument become a highly recommended tool for monitoring and tracking trace organic pollutants in the environment. Determination of chloro-phenols in water and soil, polycyclic aromatic hydrocarbons (PAH), unleaded gasoline, dioxins, dibenzofurans, organo-chlorine pesticides such as endrin, dieldrin, herbicides, phenols, halogenated pesticides are very convenient to be screened by this facility.

Liquid Chromatography coupled with Mass Spectrometry (LC-MS/MS)
Make: Agilent, Model: 6420

Liquid Chromatography (LC) coupled with the mass spectrometry (MS/MS) is a powerful analytical technique that combines the separating power of liquid chromatography with the highly sensitive and selective mass analysis capability of triple quadrupole (QQQ) mass spectrometry. A sample solution containing the analytes of interest are pumped through a stationary phase (LC column) by a mobile phase flowing through at high pressure. Different chemical interactions between the components of the sample, stationary phase and the mobile phase results in different migration rates through the LC column which leads to the separation of mixture analytes into pure chemical compounds. The wide variety of stationary phase and mobile phase combinations allow for customizing a separation to suit many complex solutions. After elution from the LC column, the effluent is directed to the mass spectrometer. The mass spectrometer for an LC-MS/MS system has an ionization source where the LC column effluent is nebulized, de-solvated and ionized in order to create the charged particles. These charged particles then migrate under high vacuum through a series of mass analyzers (quadrupole) by applying electromagnetic fields. A specific mass/charge precursor ion (m/z ratio of parent ion) is targeted to pass through the first quadrupole, excluding all other mass/charge ratio particles. In the collision cell, the selected mass/charge ions are then fragmented into product ions (or daughter ions) by collision with an inert gas. The third quadrupole is used to target specific product ion fragments. The resulting isolated product ions are then quantified with an electron multiplier. This transition of ions from the precursor to product ion is highly specific to the structure of the compound of interest and therefore provides a high degree of selectivity. The lab equipped with Agilent-6420 LC-MS/MS instruments with C18 Column of 15cm length and 2.5μm pore size. And the instrument is tuned to identify and quantifying of polar organic molecules for example acephate and fenvalerate pesticides in natural water/soil/sediment samples. However, prior to injection of the water samples the organic residue in the samples must be pre-concentrated by using the standard EPA methods while the residue of soil/sediment sample must be extracted by using the digestion techniques or by using the suitable QuEChERS for the targeted molecules.

Surface area analyser
Make: Micromeritics; Model: Tristar-3020kr

This instrument is used to determine the specific surface area of powders, solids and granules. It analyses single and multipoint BET surface area, thickness, pore area distributions (BJH method), total pore volume, pore surface area, t-Plot, Langmuir surface area and Isotherm plots. It can analyse the surface area of samples up to 0.02 m2/g using krypton gas. It can analyse three samples at a time and the working principle is the adsorption/desorption isotherms and pore volumes of the adsorbents were determined by nitrogen adsorption–desorption isotherms, measured at 77 K. The shape of the typical isotherm provides various useful information on the large uptake of nitrogen at low P/P0 indicating filling of the micropores. The linear portion of the curve represents multilayer adsorption of nitrogen on the surface, and the coverage upward portion of the curve represents multilayer adsorption of nitrogen on the surface and the concave upward portion of the curve represents filling of meso-and micropores. The Surface Area Analyser is also capable of determining the pore size distribution in solid matrix.

Fourier Transform Infrared Spectrometer (FT-IR)
Make: Agilent; Model: Cary-630

Infrared spectroscopy provides specific information about the vibration of chemical bonding in a molecular structure. Vibration spectrum represents a fingerprint of a sample making it useful for analyzing organic, inorganic and biological compounds. It is a major versatile tool for the qualitative analysis and quantitative identification of every different form of materials. During Fourier transformation, the interferogram pattern gives rise to the spectrum which is carried out mathematically with a computer. The present model (Cary 630 FTIR) has a spectral range of 100-4000 cm-1 with a spectral resolution of < 2 cm-1. The instrument is capable of identifying the functional groups present in a compound, useful for quantitative estimation of resins from industries as well as chemicals, pharmaceuticals, petroleum products, oil and grease in water etc.

Spectrofluorometer
Make: Agilent; Model: Carry Eclipse

Spectrofluorometer uses high intensity light sources to bombard a sample with as many photons as possible. This allows for the maximum number of molecules to be in an excited state at any one point in time. The light is either passed through a filter, selecting a fixed wavelength, or a monochromatic in nature, which allows a wavelength of interest to be selected for use as the exciting light. The emission is collected at 90 degrees to the exciting light. The emission is also either passed through a filter or a monochromatic before being detected by a photomultiplier tube, photodiode, or charge-coupled device detector. The signal can either be processed as digital or analogue output. The Spectrofluorometer consists of a light source, an excitation monochromatic, a sample holder, an emission monochromatic, and a detector. The reference is generally a solution of a strongly fluorescent molecule with a broad absorbance spectrum such as rhodamine. The reference is necessary to correct for lamp output, especially when varying the excitation wavelength, and to correct for differences in detector sensitivity. The spectrofluorometer has the capabilities of measuring the fluorescence signature of an analyte in a sample based on its specific excitation and emission wavelengths. The fluorescence signature can be correlated to the concentration level of the analyte in the sample and mainly used for plant pigment analysis and PHC (Petroleum Hydrocarbon) detection.

Hydrochemical Analytical Laboratory

Hydrochemical Analytical Laboratory is the part of the Central Chemical Laboratory (CCL) at NCESS with an objective of providing high-quality hydrochemical analytical services to ensure the safe water in natural environment and supports research on water quality and quantity under the global change (a combination of climate change and rapid socio-economic development). The lab not only offers analytical services to NCESS, but also provides the services to other government agencies, public industries, other institutional researchers and private clients on the payment/service basis. This laboratory instruments/facilities offers a complete and customized services for major cation, nutrients, trace metals, rare earth elements and major anion analysis for groundwater, river water, spring water, drinking water, industrial and domestic/agriculture waste water. The laboratory follows the established analytical procedures for analysis of targeted chemical species while available list of instruments/facilities with brief details are provided below.

Instruments/Facilities available with Hydrochemical Analytical Laboratory:

1. Continuous Flow Analyser (CFA)
2. Microwave Plasma-Atomic Emission Spectrometry (MP-AES)
3. UV-VIS-NIR Spectrophotometer (UV-VIS-NIR)
4. UV-Vis Spectrophotometer
5. Voltametric Analyser (V-analyser)
6. Wet Chemistry lab with Millipore water unit

Continuous Flow Analyser (CFA)
Make: Skalar, Netherlands; Model: San++

The Continuous Flow Analyser is a segmented flow analyser which is used to measure the amount of nutrients present in estuarine, wastewater, fresh water and seawater samples. The nutrients in sediment and soil samples can be analyzed after proper digestion methods. This instrument is having two chemistry units, in the first one, nutrients such as silicate, ammonia, nitrate, nitrite, phosphate (five chemistries) can be analyzed simultaneously by colorimetric method, while ammonia is measured by fluorometrically. In the second chemistry unit, chloride, sulphate, fluoride, hardness and alkalinity (another five chemistries) can be analyzed by the colorimetric method. Apart from this total nitrogen and total phosphorus also can be analyzed separately with high accuracy and precision. The Continuous Flow Analyzer consists of computer-controlled sampler for up to 140 samples with separated standard and sample positions, built in rinse pump, optional automatic diluter station for automatic pre- and post-run dilutions, and automatic standard preparation. The method of analysis is segmented flow of reagents and samples running through a chemistry module to undergo handlings like mixing, heating, dialysis, distillation, etc. until a reaction product is developed. Then the flow passes through a flow cell and the absorbance are measured according to the Beer-Lambert law. The instrument is capable of measuring the elements/ions/compounds in ppb levels.

Microwave Plasma-Atomic Emission Spectrometry (MP-AES)
Make: Agilent; Model: 4210

The Microwave Plasma-Atomic Emission Spectrophotometer (MP-AES) system is useful in identifying and quantifying the metal elements (almost all non-radioactive metals in the periodic table) which is a cost-efficient and easy-to-use for a wide range of applications from routine to complex precious metals analysis. This system offers higher sensitivity and faster throughput capabilities than flame atomic absorption. MP-AES runs on nitrogen extracted from air using the nitrogen generator and hence no spending on the He/Ar gas cylinders like the ICP-MS. The plasma once generated will sustain by axial magnetic and radial electrical fields and the analytical samples are typically nebulized prior to interaction with the plasma. The atomized sample passes through the plasma where the metal atoms electrons are promoted to the excited state by absorbing energy from the plasma. When de-excitation takes place the wavelength which is characteristic to the particular metal atom will be emitted. The light beam emitted from different metal atoms will be focused by using the optical system and then focused beam is split into monochromatic wavelengths by using the prism and the intensity of each emission are detected using the highly efficiency CCD (Charge Coupled Device) detector. Major metal ions and trace metal analysis of liquid samples can be carried out instantaneously while the soil/sediment/rock samples must be extracted to liquid form by using the proper digestion techniques, then only can be injected into MP-AES and any high concentrations of the analyte must be diluted to standards limits range.

UV-VIS-NIR Spectrophotometer
Make: Shimadzu; Model: UV-3600 plus

The optical absorption of samples in the wide range of 185 to 3300 nm regions are measured by using this instrument for a given solid or liquid samples with different detection modes for different samples. Absorption measurements based on the Beer-Lambert law in the UV, Visible and Near IR regions of the electromagnetic spectrum provides the information about electronic transitions in a given sample and thereby can detect the concentration of the analyte with respect to the standards. For example, amount of sulphate in the given sample can identified and quantified by using the absorbance at 420 nm, like wise any chemical species which has the absorbance maxima between 185 and 3300 nm can be identified as well as quantified by using this UV-VIS-NIR Spectrophotometer. A wide range of elements/compounds in the environment can be quantitatively identified using colorimetric procedure. The concentrations of UV active compounds and VIS active dyes can be determined directly without the addition of colouring reagents.

Voltametric Analyser
Make: Metrohm; Model: 797 VA Computrace

The 797 VA Computrace is a modern Voltametric measuring stand that is connected to a PC via a USB port and the computer software provided, controls the measurement, records the measured data and evaluates it. Voltametric trace analysis and additive determination in electroplating baths with a single instrument provides the possibility to carry out metal analyses with improved sensitivity. With this Voltametric Analyser, it is also possible to differentiate between various oxidation states of metal ions or between free and bound metal ions. Not only metals, but also many different organic compounds can be determined by voltammetry. A range of special anions can also be determined voltametrically, particularly the environmental relevant species such as cyanide, sulfide or nitrite and nitrate.

Wet Chemistry Lab

The CCL at NCESS is equipped with a brand new futuristic Wet Chemical Lab with adequate safety measures as well as standard reagents and glassware apparatus. This includes standard benchwork set up for titrations, preparation of reagents and standards, microbalance with anti-vibrating table, fume hood, filtration unit, standard chemical storage and Millipore unit for water purification. A laboratory fume hood is a ventilated enclosure that is built inside a chemistry lab for conducting experiments that release toxic chemicals. The fume hoods have an efficient air exhaust system that allows expulsion of toxic gases. The water used for the laboratory needs are taken from Millipore water system which combines the production of Type 2 (pure) water and Type 1 (ultrapure) water in a single unit directly from tap water. Vacuum filtration is a technique for separating a solid product from a liquid. The water samples are poured through a filter paper in a Buchner funnel by which the solids present in the water are trapped by the filter and the liquid is drawn through the funnel into the flask below by using the vacuum pump. The chemicals that are required for the laboratory works are stored in a well-arranged manner in the chemical store.

Standard bench work set up in the Wet Chemistry Lab

Fume hood set up in the Wet Chemistry Lab

Millipore water purification unit in the Wet Chemistry Lab

Geochemical Analytical Laboratory

Geochemical analytical laboratory is the integral part of the Central Chemical Laboratory (CCL) at NCESS with an objective of providing high-quality geochemical analytical services and supports the research on soil, rock and sediment which are the vital resources of the natural environment that are put under severe pressure by multiple socio-economic utilizations along with the water. Geochemical investigations of earth system resources (rock/soil/sediment) provide the adequate information on mechanisms that are responsible for changes in the natural environment. The lab not only offers analytical services to NCESS, but also provides the services to other government agencies, public industries, other institutional researchers and private clients on the payment basis. This laboratory equipped with state-of the art instruments/facilities and offers the analysis for C, H, N and S elements, total organic carbon (TOC), total carbon (TC), particle size analysis along with textural characterization and loss of ignition for soil/sediment samples. The lab also offers soil/sediment digestion methods using with high concentrated acids and fume hood for heavy metals, rare earth elements and trace metal analysis. List of instruments/facilities available with geochemical analytical laboratory and their brief details are provided below.

Instruments/Facilities available with Hydrochemical Analytical Laboratory:

1. Total Organic Carbon analyser (TOC)
2. C, H, N and S elemental analysis (CHNS analyser)
3. SediGraph particle size analyser
4. Textural characterization and sample digestion facility for soil/sediment

Total Organic Carbon Analyser
Make: Elementar; Model: Vario TOC Select

The Total Organic Carbon (TOC) is one of the most important composite parameters in the assessment of the organic matter present in the given sample of water or soil or sediment. Total organic carbon (TOC) is the amount of carbon found in an organic compound and is often used as a non-specific indicator of water quality. In addition to the TOC, parameters like Total Carbon (TC), Total Inorganic Carbon (TIC) are also measured where the TC is the sum of the TOC and TIC. Analytical technologies utilized to measure TOC are of completely oxidizing the organic molecules in an aliquot of sample water/sediment to carbon dioxide (CO2), there by measuring the resultant CO2 concentration and expressing this response as carbon concentration. The TOC analyser first digests the inorganic carbon with the help of Ortho phosphoric acid which may be present in the water from sources such as dissolved CO2 and bicarbonate, and then the CO2 generated from the oxidation of organic molecules in the sample is measured.

C, H, N and S elemental analyser (Vario EL Cube)
Make: Elementar; Model: Vario EL Cube

The C, H, N and S elemental analyser finds utility in determining the percentages of Carbon, Hydrogen, Nitrogen, and Sulphur of the given water or soil or sediment sample. And the working principle is based on the "Dumas method" which involves the complete and instantaneous oxidation of the sample by "flash combustion". The combustion products are separated by a chromatographic column and detected by the thermal conductivity detector (T.C.D.) which gives an output signal proportional to the concentration of the individual components of the mixture. Here the present CHNS analyser at CCL uses the built-in chromatographic column which converts the sample compound and elutes it in the form of NO2, CO2, SO2, H2O which are then detected with the help of thermal conductivity detector (T.C.D.).

SediGraph
Make: Micromeritics; Model: SediGraph III plus

Micromeritics SediGraph has remained the standard instrument for particle size analysis. Particle size distribution is measured using the sedimentation method. Particle mass is measured directly via X-ray absorption. The SediGraph determines the equivalent spherical diameter of particles ranging from 300 to 0.1 micrometers. The SediGraph III Plus is equipped with a versatile, easy-to-use user interface that includes point-and-click menus, customizable reports, tables and data export features. In addition to tabular data, different graphical analysis plot types are also available including: cumulative mass, area, and number, settling velocity distribution, process control charts, log probability, baseline/full scale references, frequency distribution, regression analyses and difference from reference.

Model/supplier: Elementar isoprime precisION IRMS, isoFLOW, and vario PYRO cube

Our laboratory houses an Elementar isoprime precisION, a high-precision isotope ratio mass spectrometer (IRMS) designed to measure natural abundances of light stable isotopes, including hydrogen (2H/1H), oxygen (18O/16O), carbon (13C/12C), nitrogen (15N/14N), and sulphur (34S/32S). The system, equipped with an integrated continuous flow interface (centrION), can be coupled with various peripherals, enabling the analysis of diverse sample types such as solids, liquids, gases, and compound-specific analyses. Typical laboratory samples include water, solid carbonate, sediments, soils, and other materials.

The IRMS is coupled with two peripherals:

• Headspace analyzer (isoFLOW): Water isotope analysis via the headspace analyzer involves equilibrating a water sample with mixed gas in a sealed vial. The equilibrated gas is introduced into the IRMS in continuous flow mode to measure H and O isotopic compositions. It also allows analysis of C and O isotopic composition in bulk carbonate solids, and C isotopic composition of dissolved inorganic carbon (DIC) by reacting them with phosphoric acid to release CO2 in the headspace, which is then introduced in the IRMS for analysis.
• Elemental Analyzer (vario PYRO cube): The Elemental Analyzer with an automated solid sampler combusts solid inorganic or organic samples, extracts gas phases, and introduces purified gases into the IRMS in continuous flow mode for stable isotope ratio measurements of C, N, and S.

In-house reference standards calibrated against international reference materials are used to achieve the accuracy and precision of our measurements. The precision of stable isotope ratios in water samples is better than 0.1‰ for O and 1.5% for H, while in carbonate samples it is better than 0.1‰ for C and 0.12‰ for O. For homogeneous combustible samples, the precision is typically better than 0.12‰ for C, 0.15‰ for N, and 0.2‰ for S.

Applications span across various fields, including Hydrology, Paleoclimatology, Geochemistry, Oceanography, and more.

Contact:

Prasenjit Das

Scientist-In-Charge

T: 0471-2511605

E: prasenjit.das[at]ncess[dot]gov[dot]in