Isotope analysis of gases, liquids, and carbonate minerals

iso FLOW is a fully automated, continuous flow preparation system for the isotopic analysis of samples which have been prepared into septum sealed vials. These samples can be derived from a diverse range of application areas such as geoscience, climate change, food adulteration, hydrology, and clinical studies, thereby ensuring that the iso FLOW is one of the most flexible sample preparation systems for isotope ratio mass spectrometry.

The iso FLOW system has unique analytical advantages for the isotopic analysis of liquid and carbonate samples compared to other commonly used techniques. For example, the equilibration technique is advantageous for the analysis of δ²H and δ¹⁸O water isotopes compared to direct injection into an elemental analyzer because there are no deleterious effects of dissolved or particulate organic compounds in the water. This is ideal for the analysis of samples such as fruit juices, wines, urine and river or estuarine waters which have substantial organic contents and so filtering or distillation of samples prior to analysis is not required.

The analysis of pure carbonate materials can be analyzed using dual inlet technology, but this is not ideal for impure carbonate samples such as apatite carbonates due to the presence of hydroxyapatite which can cause an interference after acid digestion. In this case, the iso FLOW is uniquely capable of analyzing these samples thanks to the UltiTrap GC separation column which purifies the sample prior to isotopic analysis.

The high-precision analysis of a diverse range of sample matrices by the iso FLOW headspace analyzer means that it is the ideal system for any IRMS laboratory.

Highlights of the iso FLOW

Flexible analysis

UltiTrap dynamic GC separation device gives increased analytical capabilities without need for cryogenics

Exceptional sample throughput

with capacity for up to 180 carbonate or liquid samples or 220 gas samples in a single acquisition.

Highest precision analysis

Experience the highest precision isotope analysis of liquid and carbonate samples

Software control of all parameters

Control of all flow rates and valves from lyticOS® Software Suite reduces instrument contact time and consumption of resources

iso FLOW headspace analyzer coupled to an isoprime precisION IRMS system

so FLOW dual-core needle injection into a sample vial

Features

Flexible GC separation

At the heart of iso FLOW is our proprietary GC separation device, UltiTrap, which leverages our Advanced Purge and Trap (APT) technology employed in our EA-IRMS systems. UltiTrap can be used in different ways for different purposes. In isothermal mode, it can operate at temperatures up to 200 °C for fast analysis of simple samples. In dynamic mode, it can operate at sub-ambient temperatures using thermoelectric cooling and rapid, dynamic heating for the improved focusing and separation of sample gases, delivering better limits of quantification for small samples.

Complete automation of every parameter

iso FLOW has complete control of every analytical parameter directly in lyticOS® Software Suite giving an unparalleled amount of automation capability to operators. By utilizing digital mass flow controllers, precise and stable control of gas flows is possible while also allowing gas flows to be varied by the method. This enables greater flexibility to utilize different methods within a single analytical sequence as well as ensuring that gas supplies are preserved by deploying sleep and wake up modes.

The highest sample throughput

The iso FLOW system offers the highest sample throughput on the market with capacity for up to 180 heated samples and 220 non-heated samples to be analyzed in a single sequence. For the greatest analytical flexibility, the temperature of the heated sample tray is controlled directly from lyticOS® Software Suite up to a maximum temperature of 90 °C ± 0.1 °C. Combined with automated sample preparation, rapid aliquoting of sample gas from the sample vial and lyticOS® data processing tools, your samples can be analyzed and processed with speed and ease.

Unique needle design

The amount of sample preparation required prior to analysis is very low when using the iso FLOW headspace analyzer. This is because the instrument can prepare the samples with automated routines using the iso FLOW’s unique multi-core needle design. The instrument uses a single needle to flush sample vials, deliver reagents to the sample vial and finally extract the prepared sample and deliver it to the IRMS for isotopic analysis. The use of a single needle makes instrument set-up easier, reduces maintenance and makes the instrument more flexible for a range of different analyses.

Product details

Breath, pure and atmospheric gases

The analysis of gas samples requires no pre-analysis treatment so an individual sample can be analyzed in less than four minutes giving exceptional throughput for large numbers of samples. Samples are prepared into 12 ml sample vials as standard, but other sample vials can be accommodated upon request so iso FLOW can be compatible with your specific sample requirements. The sampling method can be defined by the operator to perform either a single loop fill or multiple loop fills giving the highest degree of optimization.

Liquid sample analysis

iso FLOW delivers market-leading analytical precisions for the measurement of δ¹⁸O and δ²H isotopes of water in a range of sample matrices. Because iso FLOW uses an isotopic equilibration technique, it is necessary to first flush the vial headspace with an equilibration gas before analysis. After flushing, the sample must be left for a given period of time to allow the isotopic exchange between the water and the headspace to reach equilibrium. After equilibrium is achieved (typically 4 hours for δ¹⁸O and 90 min for δ²H analysis using a platinum catalyst), iso FLOW will automatically begin to analyze the equilibrated samples and then deliver them to the IRMS for isotope analysis. iso FLOW uses a single equilibration gas rather than two to reduce the number of gas cylinders required in the laboratory.

Carbonate sample analysis

The analysis of carbonate materials and dissolved inorganic carbonates (DICs) requires the delivery of phosphoric acid to digest the carbonate sample. This forms CO₂ gas which is then passed to the IRMS for isotope analysis. iso FLOW uniquely uses a direct drive acid pump rather than a belt-driven acid pump which gives significantly more precise and faster delivery of acid into the sample vial. Once the acid reaction of all 180 carbonate samples is complete, iso FLOW begins analysis of the resultant CO₂ delivering exceptional isotopic precisions for samples down to 100 µg in size.

iso FLOW can be configured as dedicated to a single analysis type, or capable of analyzing all samples types allowing you to set up the system in the best way for your laboratory sample demands. The main modes of analysis are:

Up to 220 pure gas and gas mixtures can be analyzed with the instrument configured in gas mode. Typically used for the analysis of δ¹³C in breath samples, or major atmospheric gas species, individual samples can be analyzed in less than 4 minutes.
Configured for liquid analysis, iso FLOW uses a dual-core microvolume needle which allows sample vial headspace to be flushed with equilibration gas as well as sampling of the equilibrated gas. Up to 180 liquid samples can be analyzed in a single acquisition using the thermally stable heated sample tray at 40 °C.
For the analysis of carbonate materials and dissolved inorganic carbonates (DICs) iso FLOW uses a direct drive acid pump for the precise micro-dosing of acid to the sample vial. Using a triple-core needle allows sample vials to be flushed, acidified, and sampled without any change to the needle. Up to 180 carbonate/DIC samples can be analyzed in a single sequence while being held between 30 – 90 °C.