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Our customers often measure some unusual things with our instruments. Liquids, gases and solids of all types, from deep sea vent water to bat breath to moth wings. We've collected a list of the weirdest… and we’ve added a few of our own as well as a few that we just made up. See if you can spot the fake analyses!

Deep-sea vent water. 2000 meters below the Southern Ocean near Antarctica, a remote-operated vehicle fires titanium samplers into a ‘black smoker’ and diffuse deep sea vents. The captured waters are brought back to the lab and analyzed for mineral content, and for the first time, for isotopic ratio. Researchers found that the water from black smokers and diffuse vents was quite different. This was presented at IAEA Oceanography Conference in March 2011 in Monaco.

Mouse saliva. Using our liquid isotope analyzer and Induction Module, saliva samples from common field mice were analyzed to investigate the diet of the mice and compared with the regional isoscape for ground water isotopes as well as extracted water isotopes from grass and plant samples.

Human Urine. Individuals differ significantly in their metabolism and quantifying individual energy expenditure has important implications for nutrition and health. Measuring total energy expenditure without altering an individual’s behavior is quite challenging -- enter stable isotopes. Patients in energy expenditure studies ingest doubly-labeled water (contains excess D and 18O) and their urine is analyzed. The result is an accurate characterization of total energy expenditure without any invasive or behavior altering measurements. Dale Schoeller of the University of Wisconsin at Madison is a pioneer in this field and has published extensively, see Rapid Communications in Mass Spectrometry, Volume 25, Issue 1, pages 3–8, 15 January 2011.

Bird’s beak. Beaks from the Western Tanger were sectioned and their isotopic content measured to trace migratory patterns using our CM-CRDS combustion system. As the beak develops, it acts as a "tree ring" record of the changing diet over the lifetime of the bird. Given the tanger's wide geographical range, it was an ideal species for such a study, comparing the isotopic time series to the western U.S.'s 13C isoscape.

Cheese. Food products come from all over the world -- often a regional specialty has a unique aspect and valued reputation associated with it. Cheese is a perfect example of this, with some types being produced in many different regions. Interestingly, the milk from each region carries with it the isotopic signature of the local water and can be used to differentiate the region of origin of the cheese. This will be presented at EGU 2012.

Bat breath. In a lab in Costa Rica, bats were injected with honey water that had been enriched in C13 and then put in a flight chamber to measure the stable isotopes of carbon exhaled or respired by the bats. It was found that bats have 15% higher metabolic rates and higher core body temperatures when they fly during daylight, implying that flight during daylight hours is less efficient. The story might be a good example to use in an introductory stable isotope course (especially during halloween season!)

Cow Breath. Our CO2 & CH4 analyzer was used to understand animal nutrition and the interplay between bio-availability of nutrients and physiological processes and responses of all livestock animals. Currently, this is being used for investigating the role of prebiotic-factors and foods on gastrointestinal health.

Chicken Breath. Our isotopic CO2 analyzer was used to monitor the 13C levels in the breath of chickens as it relates to responses to bacterial and viral infections. Mouse breath was also measured for the same purpose.

Seal whisker. Using our CM-CRDS combustion system, stable isotopic analysis was performed on sections of a seal whisker to trace out feeding patterns as a function of time as the whisker grew. This shed light on the migratory pattern of seals. Plucking the seal whisker was the hard part!

Truffles. To understand the association of tree roots and soil microorganisms to the development of truffles, 13C measurements from soil chambers were compared to the 13C in leaf detritus and the 13C of the truffle itself (Tuber macrosporum) from combusted samples. It was found that the carbon in truffles is closer in 13C content to daytime soil-respired CO2 than to that directly from tree roots themselves, contradicting the long-held hypothesis that truffles growth is metabolically linked to root health, proximity and respiration.

Cow Ears. Of the world’s top eight beef-exporting countries, only the US and India do not have mandatory tracking systems. And, while the USDA is developing a rule “Traceability for Livestock Moving Interstate”, the use of ear tags for cattle tracing is of great concern since an estimated 30% of tags fall off. So, the use of stable isotopes and DNA testing as a joint traceability tool has significant value. As a test, the ear notches that are discarded when an ear is tagged were freeze dried, combusted and analyzed for d13C and dD using a Picarro system. The results showed that three states (and corn versus grass fed) cattle could be distinguished.

Mosquitoes. Stable isotope technology is a powerful tool which offers the opportunity to trace the source, distribution and movement of vector populations across the landscape, and allows estimates of vector population size and enables determination of which males, wild, sterile or genetically modified, are inseminating the native female population. THese factors are critically important in any vector control program, but are essential in implementing sterile insect techniques or genetic-based eradication strategies. Many current malaria control projects reiterate that, for optimal use of intervention and resources, information on the density and movement of the mosquito population is required. Stable isotope tools can provide this essential information unambiguously. By feeding male mosquitoes 13C-labeled nutrients, releasing, then catching a sample of the population (male and female) and finally "analyzing" them using the CM-CRDS system for d13C, this signature can be used in order to understand their mating patterns.

Moth wings. d13C analysis of moths can elucidate their energy expenditure patterns, i.e. whether they are using their adult-stage nutrient consumption for flight purposes or whether they are tapping into their larval stage nutrient reserves.

Marijuana. Have you ever wondered how the confiscated marijuana in the US is traced back to either Canada or Mexico? Marijuana grown indoors (e.g. Canada) has a different d13C signature than the Marijuana crops grown outdoors (Mexico).

Platypus egg. It has been hypothesized that during egg production, the duck-billed platypus and others of the monotremes species change their diet, and in so doing, their overall bodily reservoir of 13C is altered to do consumption of different aquatic animals than at other periods during the year. The 13C content in the eggs has been measured and confirms this.

Bison feces.  A group of scientists at Kansas State University was interested in investigating bison migration patterns. By measuring and comparing the changes in the stable isotope signature in bison feces to the stable isotopes found in local water sources, this information was used to identify where the bison were drinking the majority of their water as they roam (like in the song!) near the Konza Prairie Biological Station.

So which ones aren’t real? Well, while the scenarios are all possible, people, to our knowledge, haven’t gotten around to measuring mouse saliva, seal whiskers, truffles, platypus eggs and bird beaks with our instruments. If anyone does perform this analysis, let us know! If you'd like more information about any of the real ones, we'd be happy to tell you more or put you in touch with the scientists who did that research -- just let us know!