44 Environmental Analysis World’s First Triple Isotope Analyser for Water
Los Gatos Research (USA) has introduced the world’s first triple isotope analyser for direct simultaneous measurement of 17O, 18O, and 2H ratios in liquid water and water vapor samples. The IWA-46EP is capable of automated, continuous or batch operation, and delivers isotopic sensitivity and precision comparable to reference isotope ratio mass spectrometer (IRMS) laboratories. And, like other LGR EP-series analysers, this new instrument incorporates proprietary thermal control, enabling accurate and precise measurements over a wide range of ambient temperatures (0 – 45°C). Together with its rugged, compact packaging, this makes the IWA 46EP ideal for remote and even airborne operation, as well as for routine laboratory use.
Traditional water isotope analysis performed using IRMS technology requires extensive sample preparation and a skilled, experienced operator. Oxygen and hydrogen ratios are
separately processed, with 17O being particularly cumbersome for IRMS. In contrast, the IWA-46EP measures all three isotopes simultaneously, directly from water-based samples, including seawater and bodily fluids. Moreover, the measurement process is automated, requiring minimal operator skill. And unlike IRMS, the IWA-46EP needs neither expensive consumables nor frequent calibration.
Applications for the IWA-46EP include atmospheric chemistry, hydrology, water cycle studies and medical diagnostics, where water isotopes can be used to determine metabolic efficiency and energy expenditure.
“We have been using a LGR isotope analyser for several years to measure 18O and 2H ratios in waters from plant leaves and stems, as well as from soil,” states Tim Griffis, Assoc. Professor at the University of Minnesota. “We use these types of data in conjunction with isotopic CO2 data to investigate linkages between hydrology and the carbon cycle. The ability to simultaneously measure 17O could add important additional insights regarding atmospheric moisture sources since the oxygen-17 excess appears to be influenced by kinetic fractionation during evaporation and is sensitive to humidity conditions in the source region.”
LGR precision gas analysers are based on the company’s patented Off-axis Integrated Cavity Output Spectroscopy (OA-ICOS) technology, a fourth generation, cavity-enhanced laser absorption technique. This unique approach is both more rugged and more precise than earlier cavity-enhanced techniques, such as conventional cavity ringdown spectroscopy (CRDS), because the performance of OA-ICOS does not need ultra-precise alignment or sub nanometer stability of its optics, or a high degree of thermal control. This ensures higher absolute accuracy, longer maintenance intervals, higher reliability and reduced cost of ownership.
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Determination of Organic Carbon and Nitrogen in Marine Sediment
An optimised technique for direct determination of organic carbon and nitrogen in marine sediment is now available from Exeter Analytical (UK).
New Data Logger for Humidity,
Temperature, CO2 and Air Pressure The new HUMLOG20 data logger from E+E Elektronik (Austria) does not need to hide in any application. The elegant housing and the large display make the data logger a real attention-grabber. The current measurement values can be read off easily thanks to the large display, even from a distance of several metres.
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The excellent price-performance ratio and the corresponding optics make the HUMLOG20 the optimal choice for numerous applications. Typical fields of application include the monitoring
Guaranteed well-being
and recording of humidity, temperature, CO2 and air pressure in museums, conference rooms or classrooms as well as climate monitoring in clean rooms, greenhouses, storage rooms or calibration laboratories.
The HUMLOG20 data logger offers multiple customer benefits;
Transmitters to detect carbon dioxide (CO2)
The amount of carbon dioxide in the environment has a significant influence on the well-being of every single person.
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seamless data logging over a period of more than a year is possible thanks to the long battery life and a memory capacity of 3.2 million measurement values.
The current measurement data are always available in the network, as the data logger is compliant with the network thanks to the integrated Ethernet interface. The data can be queried, displayed and saved on a PC in real time.
A simple analysis and visualisation of the measurement data is possible with the SmartGraph3 software included in the scope of delivery. In addition, a fast response to possible deviations is supported by a visual and acoustic alarm function.
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The filter based technique, using an Exeter Analytical Model 440 CHN Elemental Analyser, provides rapid and routine analysis of marine sediment. Results are expressed in micrograms of Carbon and Nitrogen detected simplifying the calculation process. Analytical sensitivity is less than 1 microgram.
As the Model 440 provides complete control over combustion parameters it is able to reproducibly achieve 100% combustion with the widest range of sediment samples. Proprietary Nitrogen analysis software uniquely enables accurate measurement of low Nitrogen levels (in the 0.1-0.2% range) with a high degree of accuracy.
The Model 440 is a static combustion system, with a unique horizontal furnace design, which enables easy removal of filter and sample ash between each sediment analysis. Consequently one combustion tube will analyse in excess of 1000 sediment samples without the need for removal and cleaning. In addition the Model 440 provides the capacity to process filters up to 47 mm in diameter in one analytical cycle. By comparison other elemental analysers, employing vertical furnace designs, will require cleaning after as little as 20 samples. Further, larger filters have to be sub sampled several times and corrective calculations made to enable analysis. The gas flow characteristics of the Model 440 analyser are superior to other elemental analysers due to the effective elimination of troublesome residue build-up. This thereby provides longer-term calibration stability as well as enhanced accuracy and precision for measured sample data.
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