Nu Perspective IRMS

The Nu Instruments Nu PERSPECTIVE IRMS is a state of the art stable isotope ratio mass spectrometer designed for flexibility, high performance, and reliability, together with a user friendly instrument control software and data analysis suite.

This next generation instrument has a wealth of novel features, giving the ultimate in performance for both routine and research applications for stable isotope ratio measurements.

The combination of the analyser geometry- field proven in the Nu Instruments Noblesse noble gas mass spectrometer- and the use of the “zoom optics” (Nu patent) gives an equivalent dispersion for CO₂ of 60cm – the largest in any commercially available IRMS instrument.

The ion source sensitivity in dual inlet mode has been determined at <600 molecules/ion (for CO₂ at mass 44) at 10kVz

Nu PERSPECTIVE ion source

All ion source parameters are under computer control, with storage of the tuning parameters for each sample gas and isotope ratio to be measured.
The ion source has integral focussing lenses (bidirectional focussing in both the vertical and horizontal planes) giving 100% transmission of ions through the analyser.
Low (<10ppm/nA) and stable (<0.03 ppm/nA/hour) H₃⁺ formation- essential for precise D/H analysis
Integral ion source heater (temperature up to 200^oC)

Nu PERSPECTIVE magnetic sector analyser

Variable mass dispersion of up to 60cm effective magnetic deflection radius (varies with the use of the patented zoom lens)
Mass range 2 to 150, mass resolution (m/Δm, 10% valley) >200
Simultaneous collection of from 2 to 6 ion beams, with 10 collectors fitted as standard to permit the simultaneous measurement of either masses 2,3; 28,29,30; 44,45,46,47,48,49; or 64,65,66,68
High stability electromagnet supplied as standard
High efficiency, narrow entrance, and deep Faraday collectors are used, that uniquely provide high resolution on all collectors
The combination of the analyser geometry and electromagnet gives high spatial separation of masses 2 and 3, allowing the measurement of D/H ratios in H₂ in a helium carrier gas without the need for any additional ion optic elements

Nu PERSPECTIVE vacuum system

True differential pumping is supplied as standard, by three BOC Edwards EXT75 70 litre/second water cooled long lifetime turbomolecular pumps, with high compression ratio for pumping of light gases (e.g. He and H₂). One BOC Edwards rotary backing pump, floor standing (inside the PERSPECTIVE cabinet)
Penning gauge for measurement of ion source pressure, with computer monitoring of both turbomolecular pump rotation speeds and temperatures, with automatic shutdown in the case of vacuum failure

Nu PERSPECTIVE instrument control and data acquisition electronics

Single module ion source supplies unit, fully computer controlled
Rack mounted data acquisition and control PCBs mounted in separate and isolated module

Nu PERSPECTIVE data system and software

Comprehensive and easy to use Windows® based control software
Full colour display of all operating parameters, e.g. ion beams, pressure gauge
True multitasking operation

Nu PERSPECTIVE reference gas injection and continuous-flow IRMS interfacing

Reference gas injection system for 5 gases (CO₂ N₂,H₂, CO, and SO₂)
Computer controlled dilutor (variable from no dilution up to 30x dilution)
Pneumatic isolation valve to isolate the ion source

Installation Requirements

Dimensions cm (width) x cm (depth) x cm (height)
Single phase power supply 230V/15A required
Compressed air @ 90psi for pneumatic valves
Closed loop water chiller/recirculator (for turbomolecular pump cooling).

Nu PERSPECTIVE Continuous Flow IRMS performance specifications

EA-IRMS mode -sample combustion to CO₂, N₂, or SO₂ with EuroVector Elemental Analyser

Gas and isotope ratio	Reference Gas Precision (1σ, n=10, 15nA peaks)	EA-IRMS external precision (1σ, n=10)	Sample Size (absolute elemental amount in capsule)
CO₂ (¹³C/^/12C)	0.06‰	0.1‰	50µg
CO₂ (¹³C/¹²C)		0.3‰	15-300
N₂ (¹⁵N/¹⁴N)	0.06‰	0.1‰	50µg
N₂ (¹⁵N/¹⁴N)		0.3‰	20-400µg
SO₂ (³⁴S/³²S)	0.1‰	0.1‰	50µg

Pyrolysis mode –solid or liquid sample pyrolysis to CO and H₂ with a HEKAtech Unit 1700^oC High Temperature Carbon Reduction Furnace

Gas and isotope ratio	Reference Gas Precision (1σ, n=10, 15nA peaks)	Pyrolysis external precision (1σ, n=10)	Sample Size (absolute elemental amount)
H₂ (D/H)	0.2‰	3‰	25µg (solid)
H₂ (D/H)		3‰	30-150µg (solid)
H₂ (D/H)		2.0‰	0.5µl (liquid)
CO (¹⁸O/¹⁶O)	0.1‰	0.3‰	50µg (solid)
CO (¹⁸O/¹⁶O)		0.6‰	25-250µg (solid)
CO (¹⁸O/¹⁶O)		0.2‰	0.5µl (liquid)

Nu Instruments GC-combustion/pyrolysis-IRMS interface

For on-line measurement of δ ¹³C, δ ¹⁵N and δD in organic compounds that are separated by capillary gas chromatography. The helium carrier gas is switched between the FID or the combustion / pyrolysis of components of interest in an oxidation or pyrolysis furnace.

Water is removed from the products of combustion using a Nafion dryer.

For δ¹⁵N measurements any N oxides are reduced to N₂ using a low dead volume reduction furnace and CO₂ is removed using a low dead volume liquid N₂ trap.

Pulses of pure reference gas are automatically introduced into the HORIZON ion source for best possible precision and accuracy.

N.B. when determining δD via the high temperature pyrolysis furnace, at the start of the GC run 3 (or more) reference gas peaks of H₂ are introduced at different major ion beam values to determine automatically the H₃⁺ correction for the GC run.

The GC combustion/pyrolysis interface includes:

An Agilent Technologies 7890A Gas Chromatograph fitted with one capillary split/splitless injector and EPC

One Flame Ionisation Detector (FID) fitted with heart cut valve

Oxidation furnace, interfaced to the 7890A, with temperature controller (maximum temperature 1200^oC)

Pyrolysis furnace, interfaced to the 7890A, with temperature controller (maximum temperature 1450^oC)

The combination of the Agilent 7890A GC together with the PERSPECTIVE IRMS meets the following specifications:

Precision <0.2‰ for δ¹³C, <1.0‰ for δ¹⁵N, and <3‰ for δD

For the measurement of δ¹³C the above precision is met with >0.8 nanomoles (10ng) of C on column; for δ¹⁵N >1.5 nanomoles (42ng) of N₂ on column; and for δD >15 nanomoles (30ng) on column.

Included will be a 30m DB-5MS 0.25mm x 0.25µm GC column

Optional autosamplers available include the Agilent 7693A, CTC GC PAL & COMBI PAL units, and the Gerstel MPS2L

ADDITIONAL SAMPLE PREPARATION ACCESSORIES

Nu Instruments “GasPrep” System

Continuous Flow Water Equilibration & Carbonate/Phosphoric Acid Reaction System

A Nu HORIZON system installed in the KISR, Kuwait (GasPrep System in the centre)

Nu Instruments has developed a new sample preparation unit to be used with the Nu PERSPECTIVE and Nu HORIZON Isotope Ratio Mass Spectrometer instruments.

The unit uses an autosampler similar to the Gilson Model 222XL, and is fitted with a temperature controlled block that can house up to 100 industry standard “Exetainer” septum capped glass vials.

When used for equilibration of water (H₂O) with either CO₂ (for ¹⁸O/¹⁶O analysis) or H₂ (for D/H analysis) the performance specifications, (when used with a PERSPECTIVE or HORIZON IRMS in continuous flow mode of operation) are as follows:

δ¹⁸O (as CO₂) Sample Size >500µl H₂O External Reproducibility <0.1‰

δD (as H₂) Sample Size >200µl H₂O External Reproducibility <2.0‰

The unit can also be used to sample CO₂ prepared from carbonate samples (e.g. DIC, solid carbonates) by the addition of phosphoric acid to the carbonate samples followed by automated determination of ¹³C/¹²C and ¹⁸O/¹⁶O ratios.

In carbonate mode the specifications are:

δ¹⁸O (as CO₂) Sample Size >50µg CO₃^2- External Reproducibility <0.08‰

δ¹³C (as CO₂) Sample Size >50µg CO₃^2- External Reproducibility <0.06‰

Nu Perspective IRMS

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