Analytical facilities

Stable isotopes | Radiogenic isotopes | Types of analysis

Stable isotopes

Facilities

NIGL is the largest UK producer of stable isotope data; particularly specialising in climate, environmental and archaeological studies. We undertake high precision 13C/12C and 18O/16O analysis of sedimentary carbonates, organics and microfossils. Our fluorination 18O/16O and 30Si/28Si analysis of diatoms and other opaline forms of silica is a unique capability in the UK, and one of only a handful of laboratories of its kind in the world. In addition the production of high precision 2H/1H, 18O/16O and 13C/12C analysis of waters is vital for modern calibration studies to aid in the interpretation of palaeorecords. We also specialise in the study of geochemical processes in the hydrosphere and atmosphere, with particular strength in 15N/14N and 34S/32S analysis of a wide variety of compounds associated with nutrient transfer and pollution in the global N and S cycles. 18O/16O analysis of nitrates and sulphates, which can provide valuable additional information on these environmentally important species, has now been added as a routine capability. For archaeological research, we have recently undertaken pioneering work on 2H/1H analysis to join 13C/12 and 15N/14N methods in palaeodietary studies; in addition we are the leading UK laboratory for 18O/16O analysis of teeth or bone. NIGL’s combined 18O/16O and 87Sr/86Sr capability is especially valuable in studies of archaeological migration.

Ice-core analysis

The laboratory has preparative and mass spectrometry facilities for determining the stable isotope ratios, at natural abundance levels, of the important light elements: 2H/1H, 13C/12C, 15N/14N, 18O/16O, 30Si/28Si and 34S/32S. We can undertake these analyses on a very wide range of sample materials relevant to studies across the environmental sciences. This is achieved by using a mixture of adaptable ‘off-line’ techniques, with access to four high vacuum gas preparation lines, alongside state-of-the-art, fully automated ‘on-line’ techniques. Instrumentation includes seven stable isotope mass spectrometer systems:

  • VG SIRA with Isoprep 18 for water 18O/16O and manifold for off-line 2H/1H
  • GV Isoprime with Multiprep and EuroPyrOH for water 2H/1H and 18O/16O
  • VG Optima with manifold for 13C/12C and 18O/16O of off-line carbonates and silicates
  • VG Optima with Carlo Erba NA1500 for 13C/12C in organics, and with IsoCarb for 13C/12C and 18O/16O in micro-carbonates
  • Thermo Finnigan Delta +XL with oxidative and reductive elemental analysers for 2H/1H, 13C/12C, 15N/14N, 18O/16O, and 34S/32S in inorganic and organic materials
  • Thermo Finnigan MAT 253 with manifold for 18O/16O and 30Si/28Si of silicates

Capabilities

Waters:2H/1H and 18O/16O of marine and fresh waters, fluid inclusions (following microlitre extractive methods), and soil/plant materials (following vacuum distillation).

Carbonates:13C/12C and 18O/16O of microfossil and other pure calcium carbonates (down to 40 micrograms), impure carbonates, and aqueous bicarbonate.

Silicates and phosphates:

18O/16O and 30Si/28Si of rock minerals, biogenic silica, and tooth/bone materials.

Organic materials:

2H/1H, 13C/12C, 15N/14N, 18O/16O, and 34S/32S of bulk organic materials (plants, soils, etc.)

Nitrogen and sulphur compounds: 15N/14N, 34S/32S, and 18O/16O of nitrate, ammonium, sulphate, sulphide, and organic N and S.


Radiogenic isotopes

Facilities

NIGL has a broad range of expertise in radiogenic isotope analysis and interpretation, focussing on U-Th-Pb geochronology, and the application of radiogenic isotope tracers in environmental, geological and archaeological studies.

We are the only laboratory in the UK which undertakes high-precision U-Th-Pb analysis of zircon and other accessory minerals by isotope dilution thermal ionisation mass spectrometry (ID-TIMS), and we maintain a strong international reputation in this field. We take a leading role in the international community through our involvement in the EARTHTIME initiative (http://www.earth-time.org/spike_newsletter.pdf). Our ID-TIMS facility is complemented by our capability in rapid in situ analysis using laser ablation MC-ICP-MS analysis.

We also specialise in the application of Sr, Nd, Pb, U and Hf isotopes in a wide range of studies involving geochemical processes in the hydrosphere, pollution, and sedimentary provenance, as well as more traditional geological applications such as mantle geochemistry and crustal evolution.

NIGL maintains state-of-the-art facilities for both thermal ionisation mass spectrometry (TIMS) and multicollector inductively-coupled plasma mass spectrometry (MC-ICP-MS).

TIMS Instruments:

  • Thermo-Electron Triton 1 (with nine Faraday collectors, RPQ high abundance sensitivity filter, an ion counting SEM system, and Multiple Ion Counting system).
  • Thermo-Electron Triton 2 (with nine Faraday collectors, RPQ high abundance sensitivity filter, an ion counting SEM system, 10 12 Ω resistors allowing measurement of lower intensity signals on Faraday detectors).
  • Finnigan-MAT 262, with Spectromat upgraded electronics and control software.

MC-ICP-MS Instruments:

  • Nu-Plasma HR. Equipped with full and pseudo-high resolution capability and a fixed collector array with zoom optics. The Nu-Plasma has interchangeable collector blocks to allow a wide range of applications in both U-Th-Pb geochronology of zircon and monazite, and isotope tracer studies.
  • Neptune Plus high-sensitivity MC-ICP-MS with multiple ion counting and nine Faraday cups.
  • Nu Instruments AttoM. Single collector sector-field ICP-MS with super-fast electronics, for rapid analysis of small sample volumes across the entire mass spectrum.

Both the Axiom and the Nu Plasma can be coupled to either of two New Wave Research solid-state Nd:YAG laser ablation systems (LUV266 & UP193SS) or one of three desolvating nebulisers (Cetac Technologies MCN6000 & Aridus or Nu Plasma DSN-100), depending on the application.

Capabilities

U-Th-Pb geochronology: NIGL has one of the world’s leading isotope dilution (ID-TIMS) U-Th-Pb dating laboratories, with the capability to date single grains of zircon weighing less than 1 microgram with Pb blanks below 1 pico- (10-12) gram. Recent developments include development of the Triton Multiple Ion Counting system for high-precision measurement of Pb isotopes, and the application of zircon annealing techniques to improve the concordance of U-Pb analyses. The ID-TIMS facility is complemented by rapid in situ analysis using laser ablation MC-ICP-MS analysis.

Lu-Hf: analysis of whole-rocks, zircons, ilmenites & garnets — using both laser-ablation and solution-mode MC-ICP-MS.

Sr, Nd: application of Sr and Nd isotopes to ecosystem, palaeoclimate, solid-earth geology, hydrological and archaeological studies. High precision Sr isotope stratigraphy. Isotope ratio measurement of Sr in silicates, carbonates, waters, archaeological and biological materials such as bone or teeth.

Common-Pb: in silicate rocks and minerals, sediments, pore waters, carbonate minerals, bone, teeth, blood, archaeological artefacts, lichen and other biological materials for both geological and environmental research.

U-isotopes in urine and other environmental materials: NIGL undertakes high precision uranium isotope measurements in waters and urine and other environmental materials including measurement of 236U. In liquids these measurements can be done at the sub-ppt level.

MC-ICP-MS laboratory


Types of analysis

Our commercial rates vary depending upon the nature of the sample, preparation procedures, size of the project and combination of analyses requested. The range of analytical services which we offer on a commercial basis is listed below. Requests for quotations should be addressed to the appropriate staff member, as follows:

General enquiries:  Mrs Béatrice Bullock-von Moos (Office Administrator) (bbullock@bgs.ac.uk)

Stable isotope analysis:  Prof Melanie J Leng 

(mjl@nigl.nerc.ac.uk)

Radiogenic isotope analysis:  Dr Dan Condon 

(ilm@bgs.ac.uk)

Science-based archaeology: Dr Jane A Evans (je@nigl.nerc.ac.uk)

Stable isotope analysis

Water, fresh or normal salinity marine (18O/16O)

Water, fresh or normal salinity marine (2H/1H)

Carbonate mineral, pure, "ready to analyse", (18O/16O + 13C/12C)

Sulphate or sulphide mineral, pure, "ready to analyse", (34S/32S)

Sulphate mineral, pure, "ready to analyse" (34S/32S + 18O/16O)

Organic matter, solid, "ready to analyse" (13C/ 12C)

Organic matter, solid, >1%N, "ready to analyse" (15N/ 14N)

Ammonium in solution, >2.5 mg N/L, (15N/ 14N)

Nitrate in solution, >2.5 mg N/L, (15N/14N)

Nitrate in solution (15N/14N + 18O/16O)

Pure mineral"ready to analyse " forms of pure silica by fluorination (18O/16O)

Pure mineral "ready to analyse" forms of pure silica by fluorination (30Si/28Si and 29Si/28Si)

Phosphate oxygen in teeth (18O/16O)

U-(Th)-Pb geochronology

Laser ablation U-Pb geochronology. 20 spots/sample for geochronology - analysis only

Laser ablation U-Pb geochronology. 60 spots/sample for provenance studies - analysis only

Laser ablation U-Pb geochronology. 20 spots/sample for geochronology - rock to result*

Laser ablation U-Pb geochronology. 60 spots/sample for provenance studies - rock to result*

U-Pb analysis of zircon, monazite etc. by ID-TIMS. 6 fractions or single grains exc. mineral separation

U-Pb analysis of zircon, monazite etc. by ID-TIMS. 6 fractions or single grains from a rock sample - rock to result* inc. mineral separation

*rock to result = you send us a rock, we send you a result - includes full mineral separation, chemical abrasion and analysis, plus grain mount production and CL imaging for laser ablation.

Radiogenic isotope analysis by laser ablation

Laser ablation Pb isotope composition.

Laser ablation Hf-isotope composition. 50 spots/sample for provenance studies, NOT including mineral separation, grain mount and SEM.

Laser ablation Hf-isotope composition. 50 spots/sample for provenance studies, including mineral separation, grain mount and SEM.

Radiogenic isotope analysis by dissolution / ion exchange chemistry

Sample preparation: varies depending upon material and analytical technique requested

Sr isotope composition

Nd isotope composition

Nd isotope composition + Sm, Nd concentrations by ID

Pb isotope composition

Pb isotope composition + Pb concentration by ID

Hf isotope composition

Hf isotope composition + Lu, Hf concentrations by ID