The quantitative and isotopic analysis of dissolved matter (e.g. dissolved organic carbon, total dissolved bound nitrogen, etc.) is of particular importance since this pool is a prime conduit in the cycling of N and C. Studying the two elemental pools simultaneously is of importance, as the transformation and transport process of N and C are inextricably linked in all biological mediated systems. iso TOC cube is the only instrument capable of performing these analyses making it an indispensable tool for ecologists, limnologists and oceanographers.
Based on the Elementar “cube” platform which has set the gold standard for elemental analysis, iso TOC cube presents a new high temperature combustion method for the quantitative and isotopic analysis of dissolved organic carbon and total bound nitrogen (TNb). By performing direct analysis on the sample, the need for laborious pre-preparation of samples is removed allowing you to quickly analyze many samples.
Since iso TOC cube utilizes high temperature combustion (up to 1,200 °C) rather than wet chemical or UV oxidation the instrument gives greater analytical robustness when analyzing refractory organic substances such as humic acids or lignin which may be only partly oxidized using other techniques. iso TOC cube also uniquely deploys a second stage reduction furnace for reduction of nitrogen oxides for 15N analysis of TNb followed by a three-stage water removal process and a halogen trap delivering pure CO2 and N2 gases to the IRMS for analysis.
For the 15N analysis of TNb, iso TOC cube uses our unique Low Concentration Module (LCM) and an integrated membrane degasser for removing dissolved N2 increasing sample detection levels. The LCM uses cryogen-free, thermoelectric cooling combined with Elementar’s Advanced Purge & Trap separation technology to achieve TNb detection levels of 25 ppm. With these technologies, iso TOC cube is the only commercially available instrument for the direct 15N analysis of TNb in aqueous samples.
When combined with an Elementar IRMS system, iso TOC cube provides a complete solution with fully integrated sample acquisition and data processing through ionOS® software. This allows the user to take full advantage of the on-board maintenance counters, sleep/wake-up functionality and synchronized methods.
Carbon isotopes of DOC
Nitrogen isotopes of TNb
Carbon and nitrogen % composition of TC/TIC/TNb, DOC/TNb
High temperature combustion unit
Quantitative sample digestion up to 1,200°C - with a ten years furnace warranty. This is the prerequisite for 100% recovery also for samples difficult to combust. Jet injection of oxygen directly to the sample leads to highest oxygen concentrations at the point of combustion and low gas consumption.
Large detection range
From 5 ppm to 60,000 ppm dissolved carbon, 25 to 60,000 ppm for dissolved nitrogen. Volume injections between 0.05 and 3 mL for optimal detection.
Real matrix separation
The new reactor concept enables real matrix separation and offers maximum protection of the combustion tube. Excellent properties for analyses of saline solutions (e.g. brine) or other complicated sample matrices.
The instrument includes an integrated autosampler with 32 sample positions which can be reloaded during analysis. The system uses a syringe with bubble elimination feature to draw up and deliver sample to the furnace.
Low Concentration Module
The Low Concentration Module (LCM) is an optional device for the pre-concentration of N2 and CO2 after combustion. The LCM provides cryogen-free, thermoelectric cooling to the Advanced Purge & Trap separation column allowing sub-ambient temperatures leading to excellent chromatography.
Control via ionOS® software gives users a straight-forward interface for simple instrument operation and maintenance.
Clean, safe, fast
The analysis of 13C only takes a few minutes, no aggressive or toxic chemicals are used, helium carrier gas.
Easy installation requirements
48 x 55 cm benchtop space, 1 power supply (230, 110, 100 V) and two gases are sufficient for maintenance free long time operation. For the optional LCM module a refrigerated water chiller is also required.