Understanding the impact of its frozen regions on the rest of the planet is the research goal of Dr. Jemma Wadham, professor of glaciology at the School of Geographical Sciences at the University of Bristol. Wadham notes, “Fifteen years ago we thought there was nothing living there. Now we know there are a large number of microorganisms inhabiting the environment.”
Wadham and her colleagues developed the Low Temperature Experimental Facility, where they perform chemical and microbiological analyses on ice, snow and meltwater in an effort to determine their biological and chemical effect on the planet. “My Ph.D. was working in the high arctic in Svalbard, about 1000 kilometers north of Norway, where I was analyzing the chemical composition of runoff from the glaciers and meltwaters and using forensic sorts of clues as to what might be going on beneath the ice sheet.
“One of the areas we’re interested in at the moment is, `Does that meltwater contain anything useful? So we’re interested in whether it contains any nutrients—nitrogen, phosphorus, whether it contains any organic carbon. Once it’s exported into the ocean, whether that then can sustain microbial or planktonic ecosystems around the major ice sheets. What we’re finding is that there’s quite high potential for runoff from major ice sheets to be fertilizing quite large sections of the ocean around these sorts of otherwise frozen wastelands.”
Working in very remote, inhospitable environments at the frozen end of the planet makes everything more difficult: getting started is a challenge; keeping contamination to minimal levels is a massive undertaking, and if something is amiss the researchers can’t return the next day to resample. Thus, when they obtain a sample, they need to know that their analyses will be reliable.
Dr. Jon Hawkings, a research assistant in the glaciology lab, says that the facility uses a range of ion chromatographs to determine the very low concentration of species in meltwaters. A key instrument is the Dionex ICS-5000 capillary ion chromatography system (Thermo Fisher Scientific, Waltham, Mass.). “The ICS-5000 takes very small samples, which is important, because weight is a concern; you can’t bring too much back. The system performs very well; detection limits are very good. That’s significant [for] samples that have come from an icy environment, as they can be quite dilute. You get very low detection limits with very small amounts of sample, and it’s a reagent-free system. Thus, compared to many other machines in the lab, the environmental impact is therefore a lot less, which is very important when you’re doing environmental analysis.” Wadham concurs, “When we go to [the] field, we bring back a lot of samples, we thaw them out and we have to analyze them very, very quickly. We can’t let them hang around, because analytes start to disappear; they get eaten by microbes.” High-throughput instruments that run night and day are needed, and because they run continuously, the people at the controls do not always have a lot of training. “The modular design of the ICS-5000 provides that capability,” Wadham notes.
“Version 7 of the Chromeleon software is very flexible,” Hawkings adds. “It can be used on a number of different systems, and it enables anyone to use the system with very little training. It’s the best software we have in the lab.” Thermo Fisher loaned the glaciology researchers an ICS-5000 system and its performance convinced them to purchase it. Hawkings explains, “The capillary system means that you have less waste, and what waste you do have is going to be pure water, so you can throw that down the sink very easily rather than pay for disposal. Sensitivity in the lab is increased for high-throughput samples compared to previous Dionex systems. The big thing we use equipment like this for is to answer big scientific questions. For our field, understanding subglacial environments, what lives in them, where the water comes from, and doing this especially in places like Antarctica, sort of undiscovered lands and learning more about them.”
Wadham says, “We tied into very big Antarctic drilling companies [and so were] able to analyze samples from several kilometers beneath the Antarctic ice sheet. You can only go there once with a probe; we need to take the water back to analyze the nutrient content, the major iron content and for the tests to be very, very reliable. We can’t get those samples again: they’re worth millions.”
As scientists spend more time exploring the further reaches of the planet, instruments that can reliably deliver accurate analyses of rare and valuable samples will become more important. While Dr. Wadham and her colleagues at the University of Bristol carry on, Thermo Fisher Scientific has released an updated model, the Dionex ICS-5000+ Reagent-Free HPIC System with Eluent Generation. It has the ability to analyze samples at capillary, microbore and standard flow rates (or any combination of two, in a dual system) at up to 5000 psi with an all-PEEK flow path.
In capillary IC, with everything scaled down by a factor of 10 to a 100, only 15 mL of water are consumed in a day at 10 μL/min; thus, the Eluent Generation Cartridge lasts for 18 months under continuous operation mode, so the system can always be on and ready to run samples. Leaving the system on and electrolytically generating the eluent means the background is less prone to changes. Response is more consistent, equilibration isn't required, and system performance can be verified quickly just by running a check standard, saving time and providing 24/7 system availability. Samples from glaciers can be run efficiently, with high resolution.