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Pocket SCiO Spectrometer Sends Chemical Composition of Anything To Smartphones
MojoKid writes: Is that a tricorder in your pocket or are you just happy to see me? All joking aside, the handheld SCiO could truly make you feel like a member Bones McCoy's medical team. The SCiO turns science fiction into science fact by shrinking mass spectrometry technology used in traditional lab settings into a device small enough to fit in the palm of your hand. While pricey handheld spectrometers have been available for researchers, the SCiO is the first such device marketed directly at consumers. To get the SCiO down to a reasonable price point, Consumer Physics uses near-IR spectroscopy and optics typically found in smartphones to measure the light reflected from any given object. Held at a distance of 5 to 15 mm from the intended target, SCiO captures reflected spectrum data and uploads it to its own cloud platform. The company's proprietary algorithms then analyze the data and send the information back down to your smartphone (SCiO require a Bluetooth connection). Reportedly, this whole process occurs within 1.5 seconds. The hope is to empower consumers to learn more about the world around them and even about the things that we put in our mouth. You'll be able to ascertain nutritional information about the foods you eat without having to rely on labels, or even determine the ripeness of fruits and vegetables with the push of a button. The Whole Foods crowd will be all over this, one would think.
Surely this device has nothing whatsoever to do with a mass-spec?
Of course not - in fact, already the headline should arouse suspicion that somebody in the chain of communication hasn't got a clue: "... chemical composition of anything ...". There no instrument at all in existence on this planet capable of doing this. It may be reasonably easy to measure the relative abundances of chemical elements and their isotopes in a sample, but not with a simple 'near infrared spectrometer', I would have thought, and as for analysing such a spectrum to get the 'chemical composition of anything', the fact is that there are millions or billions of common molecules arounds - such as proteins - and we do not have any simply understanding of what their spectral fingerprint might be. Single atoms have well-defined, discrete spectra, but complex molecules may not even have discrete spectra.
On top of that - even if we were able to calculate and measure spectra perfectly, and assuming that the very limited 'near infrared' bandwidth is sufficient to distinguish all molecules, the analysis part is likely to require massive processing power. All in all - a load of hyped up nonsense.
Designing spectrometer is what I do for a living and with my experience and knowledge, I have serious doubts this device has sufficient resolving power to do what they claim it can/would/should do. To identify chemical components, you need a minimum spectral resolution (depending on the species you want to identify). To do quantitative analysis, the requirements are event higher. Typically, for solid NIR spectroscopy, I would aim at 2 to 4 cm^-1 spectral resolution. Under this, you can maybe check for the presence of a specific compound or compound family, but the capability to do so will be very dependent on the overall chemical composition.
Its possible to reduce the size of a spectrometer while somewhat keeping the resolution. But that goes only up to a certain extent... and that goes only with trade on signal to noise ratio. At some point physics overtakes wishful thinking. Reducing the instrument, and thus the optical throughput, you need longer measurement times to achieve adequate signal quality. Quantitative analysis with a (large) lab NIR spectrometer can take minutes, depending on the material being analysed. When you design spectrometers, you are constantly trading on aspect for another and by bringing a NIR spectrometer to that size, you traded a LOT of stuff away.
I also see spectral calibration being an issue with this device, then it works in reflectance and not in transmittance. It cannot be self-calibrating and directly provide a transmission/absorption spectrum. Maybe it is calibrated once during the production and assumed to be stable? If that is sufficient is, from my experience, questionable.
On the other hand, this is a very exiting breakthrough. I might even get my hands on one for fun. Why? because its, as they so well market it, a liberalisation of matter. Its a first step in being able to identify any substance that we get our hands on. While it may not yet be able to provide a full chemical make-up of a product, with enough a priori information it may be very useful.
Let me give you an example where such a device can be its money worth. When you buy fruits and vegetables that are bio/organic, you want them really to be that way. This decision to spend more money on these healthier food items is solely based on trust, which is often exploited. I doubt that the analysis of such a product can do what they claim (most of the return information is most likely deduced from the a priori information provided). But even with a limited spectral resolution and sensitivity, it should be able to identify spectral signatures of typical herbicides and pesticides.
You will not be able to determine raw elements with a NIR spectrometer. With a NIR-LWIR spectrometer, you can only identify molecular compounds, because what you are observing is actually the vibration modes of the molecules. In this spectral range, you will have a lot of signature for organic compounds. So you may be able determine if something is made of plastic. Determining the kind is trickier because most plastics are actually very similar and would require a device with higher spectral resolution to make such a determination.
For elementary elements (iron, copper, gold, etc.), you can forget it. That device will not help you.
Come on AC, be nice. You can't use near-IR to identify unknowns when you have a nearly infinite number of possibilities. There are devices for monitoring reactions using Near IR, but their use requires intimate knowledge of the contributing components and calibration of each one. If some new unknown shows up you don't get enough information from their near IR absorbance to assign identity. I 've been doing this stuff for 40 years so I don't need to read the wiki article and become an instant expert like you. However, I will read the wiki article and see if I can understand why you've been mislead.
I just looked at the article. You owe me an apology.