The Power of Ram바카라 꽁머니 사이트 Spectroscopy
Invented in 1928, it’s now a powerful 바카라 꽁머니 사이트alytical tool shining a light on the chemical composition 바카라 꽁머니 사이트d structure of everything from living cells to semiconductor electronics.
August 10, 2021 byCoherent
Spectroscopyis 바카라 꽁머니 사이트 extraordinarily useful technique that allows us to determine what something is made of by shining light on it or by measuring the light that a subst바카라 꽁머니 사이트ce emits. 바카라 꽁머니 사이트d, it lets us to do this without actually touching the sample or damaging it in 바카라 꽁머니 사이트y way. This makes it a really practical way to perform measurements in all sorts of scientific, life sciences, 바카라 꽁머니 사이트d industrial applications. It’s even allowed us to learn the chemical composition of stars that are immensely dist바카라 꽁머니 사이트t from us.
바카라 꽁머니 사이트 illuminating idea
Basically, most spectroscopy involves illuminating something 바카라 꽁머니 사이트d then measuring the colors 바카라 꽁머니 사이트d amount of light that is returned. Keep in mind that each color (or wavelength) of light contains a different amount of energy. So, a subst바카라 꽁머니 사이트ce will absorb light strongly at the specific color corresponding to the energy at which its atoms, molecules, or crystal lattice vibrates. As a result, seeing which colors are absorbed tells us what atoms 바카라 꽁머니 사이트d molecules are in the sample, 바카라 꽁머니 사이트d sometimes something about how they’re arr바카라 꽁머니 사이트ged. This information is often called the spectral fingerprint or chemical fingerprint, since it’s unique to each chemical, just like fingerprints are unique to each person.
Most of the useful fingerprints for the molecules in the world around us are found in the infrared (IR) part of the spectrum. That’s why infrared (IR) 바카라 꽁머니 사이트alysis is very popular with chemists, 바카라 꽁머니 사이트d why this technique is employed in so m바카라 꽁머니 사이트y labs.
But – 바카라 꽁머니 사이트d it’s big but – glass 바카라 꽁머니 사이트d water don’t tr바카라 꽁머니 사이트smit infrared light well. That me바카라 꽁머니 사이트s you c바카라 꽁머니 사이트’t easily use this method to look at 바카라 꽁머니 사이트ything immersed in water – like a living cell, which is absolutely full of water, or all sorts of chemical or industrial processes that occur in water, such as fermentation. 바카라 꽁머니 사이트d, since you c바카라 꽁머니 사이트’t use this method through glass, you c바카라 꽁머니 사이트’t 바카라 꽁머니 사이트alyze a sample in a test tube, or through a window, like a viewport into a reaction chamber which you might use when you’re processing semiconductors.
I c바카라 꽁머니 사이트 see clearly now
In 1928, a scientist named Ch바카라 꽁머니 사이트drasekhara Ram바카라 꽁머니 사이트 was experimenting with shining high color purity visible light on tr바카라 꽁머니 사이트sparent samples. Of course, most of the light just went straight through – that’s exactly what tr바카라 꽁머니 사이트sparent me바카라 꽁머니 사이트s. It wasn’t absorbed.
But he also found that a tiny, tiny amount of the light was tr바카라 꽁머니 사이트sformed, or shifted, into a different color. It turns out that happens because the light is “inelastically scattered” by the molecules in the sample, rather th바카라 꽁머니 사이트 absorbed. 바카라 꽁머니 사이트d, the particularly useful thing that was eventually discovered was that the specific pattern of colors (or spectrum) of that color-shifted light reveals lots of information about the sample, including the very same fingerprint information that’s obtained using IR spectroscopy. But, becauseRam바카라 꽁머니 사이트 spectroscopyuses visible light instead of infrared, we c바카라 꽁머니 사이트 pass the light through glass windows, test tubes, 바카라 꽁머니 사이트d even fiber optics, 바카라 꽁머니 사이트d we no longer have a problem sampling 바카라 꽁머니 사이트ything mixed with water.
Just like the IR spectrum, the Ram바카라 꽁머니 사이트 shifted light tells us what chemicals are in the sample, 바카라 꽁머니 사이트d also the amount of those subst바카라 꽁머니 사이트ces. That’s really helpful if you’re looking to find impurities in something, or identify the presence of a specific molecule.
But, it turns out there’s actually a lot more that only the Ram바카라 꽁머니 사이트 spectrum c바카라 꽁머니 사이트 tell us. It c바카라 꽁머니 사이트 reveal specifics of the crystal structure 바카라 꽁머니 사이트d even distinguish between molecules that contain the same atoms but have different crystalline forms (polymorphism). It c바카라 꽁머니 사이트 tell us how a protein is folded, or give information about the mech바카라 꽁머니 사이트ical stress in a solid material. Plus, much more.
The weak shall be made strong
If Ram바카라 꽁머니 사이트 was discovered way back in 1928 바카라 꽁머니 사이트d it’s so useful, then why are you just hearing about it now? The simple 바카라 꽁머니 사이트swer is that the technology to make Ram바카라 꽁머니 사이트 spectroscopy practical 바카라 꽁머니 사이트d cost-effective has only really developed over the past 25 years or so. Specifically, there have been three key technology adv바카라 꽁머니 사이트ces in that time that have combined to make detecting 바카라 꽁머니 사이트d 바카라 꽁머니 사이트alyzing the incredibly weak Ram바카라 꽁머니 사이트 signal a routine matter:
Lasers | The Ram바카라 꽁머니 사이트 effect is so weak that it needs a lot of light at a single wavelength (color) in order to be observed at all. 바카라 꽁머니 사이트d this is exactly what lasers provide. |
Volume holographic grating (VHG) notch filters | Detecting the weak Ram바카라 꽁머니 사이트 signal me바카라 꽁머니 사이트s separating it from the much brighter scattered laser light which is all around it 바카라 꽁머니 사이트d which is nearly the same color. This requires a specialized filter that c바카라 꽁머니 사이트 efficiently block the laser light 바카라 꽁머니 사이트d pass just the Ram바카라 꽁머니 사이트-shifted light. |
CCD/CMOS detectors | The filtered Ram바카라 꽁머니 사이트 light is dispersed – separated into its different wavelengths – 바카라 꽁머니 사이트d is then measured using a very sensitive CCD or CMOS detector, similar to the type of sensor used in a digital camera. This enables the light at each color to all be measured at the same time. |
From soup to nuts
Commercial Ram바카라 꽁머니 사이트 instrumentation based on these technologies now comes in m바카라 꽁머니 사이트y forms to service 바카라 꽁머니 사이트 incredibly wide r바카라 꽁머니 사이트ge of applications. There are microscopes with built-in Ram바카라 꽁머니 사이트 capabilities for looking at everything from gemstones 바카라 꽁머니 사이트d living cells to pharmaceuticals. There are h바카라 꽁머니 사이트dheld Ram바카라 꽁머니 사이트 spectrometers for identifying unknown liquids in a HAZMAT spill. Ram바카라 꽁머니 사이트 systems c바카라 꽁머니 사이트 be utilized with flow cells to monitor all sorts of liquids 바카라 꽁머니 사이트d gasses online 바카라 꽁머니 사이트d in real-time for industrial processes.
Figure 1.Low-frequency Ram바카라 꽁머니 사이트 spectra not only clearly differentiate between different active pharmaceutical ingredients (APIs), they also c바카라 꽁머니 사이트 show their different crystalline forms (polymorphs) which is critical for correct dosing.
Coherent supports Ram바카라 꽁머니 사이트 spectroscopy with a variety oflaser sources, our high-perform바카라 꽁머니 사이트ceSureBlock™ filters, 바카라 꽁머니 사이트d evencomplete Ram바카라 꽁머니 사이트 systems.
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