Code of Conduct
Page 1 of 2 1 2 LastLast
Results 1 to 30 of 41
  1. #1

    Question Wavelengths of light, and respective degredation...

    Has anyone here studied extensively the relationship between various wavelengths/spectrum of light, and how it corresponds to the degredation of our favorite fragrances?

    I am very curious to know which spectrums/wavelengths cause the most harm to which compunds, and which wavelengths are relatively harmless to each particular type of fragrance oil.

    If anyone has any knowledge, external links, or advice on books to read, I would be very thankful and interested.

    Be good.
    Peace.

  2. #2

    Default Re: Wavelengths of light, and respective degredation...

    Say a bit more, Dullah. Is the question whether perfume stored in partial shade but not in complete darkness will still be damaged? If that's the drift of your question, I'm very interested, too.

  3. #3

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by DULLAH View Post
    Has anyone here studied extensively the relationship between various wavelengths/spectrum of light, and how it corresponds to the degredation of our favorite fragrances?

    I am very curious to know which spectrums/wavelengths cause the most harm to which compunds, and which wavelengths are relatively harmless to each particular type of fragrance oil.

    If anyone has any knowledge, external links, or advice on books to read, I would be very thankful and interested.

    Be good.
    Peace.

    Now, THAT's a question... basically he is asking which color of light affects perfumes the most.
    Since it is common knowledge that "heat" (infrared light) is not as dangerous as daylight, I'd say, high frequencies (short wavelenghts) are the worst...
    I would believe that Ultraviolet light is the most dangerous for perfumes as it is also the most dangerous for organic materials and it has the higest energy content. Now I am not chemist or anything... But that is my guess.

    You could search for Photo-chemical Reactions and Degradation by Ultraviolet light or Infrared light. If oils, organic compounds like aldehydes and alcohol are sensitive to that kind of light... well there is your answer.
    Last edited by irish; 21st July 2008 at 05:08 AM.

  4. #4

    Default Re: Wavelengths of light, and respective degredation...

    I learned physics in University (esp. Quantum Physics), but my English is not so good...
    I`ll try anyway.

    Let`s say that any molecule perfume consist of has its own characteristic frequencies. It`s like balls connected with springs - different mass of balls and elasticity of springs results to different frequencies. And every connection has its own frequency of oscillation (well, there`re compression-extension frequency, rotation frequency, etc).
    The more complex is molecule - the more frequencies it has.
    Then - every modern scent consist of tens and hundreds of molecules. Naturals gives us up to 300-500 components with their own frequencies.

    When the light hits the molecule, it absorb a quantum of specified energy and frequency and oscillates faster. It could then goes two ways - 1) the spring broke down and molecule become two (smell differs); 2) molecule emits energy by quantum of the same (or lower because of friction and dissipation, so temperature of perfume is going higher) energy.

    How to determine the most harmful spectrum for perfumes?
    It`s not the one coloured rays - but the broad spectrum. White light has the most broad spectrum, from unfrared to ultraviolet (UV does not counts, as flacons are made from glass which blocks UV almost 100%), so it does more harm to perfume.

    By the way - infrared light is harmful too, as it does heaten up a perfume, and glass does not block it.

    Sorry for any mistakes (and for my school-like description too) - Luca Turin described the mechanism very good in his first book.
    If by any chance you found the book like Popular Spectroscopie (or smth like that) - you`ll found the answer
    sunlight
    Vetiver The Great!!!

  5. #5

    Default Re: Wavelengths of light, and respective degredation...

    Two things to add:
    sunlight has almost equal high intensity from 410 to 810 nm (InfraRed to UltraViolet).
    any liquid do absorb all the light quantums except the colour it has.

    I believe that there`s a reference-book of absorption spectrum for every aroma-chemical (lactones, aldehydes, terpenes, esters, patented synthetic molecules, etc.), so it could be easily found in physics or chemistry library (for patented - in those Givaudan, Takasago, etc).
    But what is not so easy to found - the light-stability tables, to see the dependence of smell versus intensity and wavelenght of light and time.

    Though I`m sure that it should have an exponential rate in time - but the smell is integrated and highly personal thing, so if molecule A under the sunlight becomes molecule B with different smell, it is still tricky to say when smell A will be disappeared fully, and what will be the smell of mixture of smells A and B.

    I believe that nobody cares about it. Spoiled perfume is just perfume with more or less different scent, that`s it. And the only advice could be - make your perfumes to avoid the direct sunlight.
    Vetiver The Great!!!

  6. #6
    Dimitrios's Avatar
    Join Date
    May 2007
    Location
    Beyond the Blue Mountains
    Posts
    3,379

    Default Re: Wavelengths of light, and respective degredation...

    Moonlight is really good for them .... seriously !!

    SALES
    JANUARY 2013 ..http://community.basenotes.net/showthread.php?t=232133

    *** SPECIAL - LUI ROCHAS , 3.3oz Sealed ***

    FLACON .. Updating Soon flacon.ambaric.net/viewtopic.php?t=43

  7. #7
    Moderator

    Redneck Perfumisto's Avatar
    Join Date
    Feb 2008
    Location
    Spiritually, Kansas
    Posts
    13,379
    Blog Entries
    37

    Default Re: Wavelengths of light, and respective degredation...

    Let me start by saying that the previous answers are very good. I agree with what they've said. Irish has a good summary of the overall, and moon_fish is showing the theory behind what I've got for you. And Dimitrios has the real answer (see PS at end...)

    I actually studied with a photochemist. I had this huge-ass answer that I was going to post, but I think I'm going to put it on my blog tomorrow instead. I mean, it was like three pages or something. Ridiculous! But this is a really cool question.

    PS Dimitrios - 100% agreement there. Nothing like testing fragrances in the moonlight with a beautiful assistant. Speaking of which..... g'nite all!
    * * * *

  8. #8

    Default Re: Wavelengths of light, and respective degredation...

    I used to think light doesnt do anything to frags - then I bought the 2007 L'eau d'Issey, which had been left out of a box sitting in a shop window for god knows how long. It literally dissapeared after 10 mins - with a very, very slight 'lemon pledge' smell to it. The same frag I tested in Myers was strong for at least an hour. I took it back and changed it for Live Jazz & XS.
    After this, I keep all my frags in a cupboard.
    Looking for: Andy Tauer - L'air du Desert Morocain & Incense Extreme

    Check out my NEW Aussie sale / trade thread here -
    http://www.basenotes.net/threads/249...76#post1801576

  9. #9

    Default Re: Wavelengths of light, and respective degredation...

    Hmmm.. I am not convinced... we need to do some testin'

    Me and the beautiful assitant A couple of unbiased researchers will volunteer to test the effects of Light on fragrances...
    they will need some Basenoters to donate some EDTs, preferably:
    -Bottles of Le Labo Rose 31 or vanilla 44 (no it wont work with another Le labo fragrance)
    -Vintage, Ultra hard to find fragrances.
    -All Natural Perfumes.

    Something tells me a full bottle of Angeliques sous La pluie will also be needed. I just finished my decant, otherwise I would gladly donate it. PM me so I can send you the address of my home an independent and serious lab.

    We all have to do sacrifices in the name of science.
    Last edited by irish; 23rd July 2008 at 07:31 AM.

  10. #10
    Dependent
    Astaroth's Avatar
    Join Date
    May 2008
    Location
    West Los Angeles
    Posts
    2,017

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by Redneck Perfumisto View Post
    I actually studied with a photochemist. I had this huge-ass answer that I was going to post, but I think I'm going to put it on my blog tomorrow instead. I mean, it was like three pages or something. Ridiculous! But this is a really cool question.
    I have the same ... errrr ... affliction as Redneck Perfumisto. My physics dissertation focussed on calculating the quantum scattering cross sections of electrons crashing into atoms. And as I'm sure Redneck would be happy to tell you, those calculations are very similar to those of light scattering from molecules. However, all physics ever delivered to me was gray hair and a cynical nature that it has taken years to get under control. Knowing what happens when different energies of electrons hit atoms has only provided me a periodic "Oooo, impressive ..." during job interviews. That, and $4.50 gets me a latte. Here's all you really need to know:

    Keep your fragrances in an opaque container as cold as they will tolerate without causing the component oils to congeal and turn the fragrance into a heterogeneous mess. Take a small amount out occasionally and put it in a small atomizer for daily/weekly use. Repeat.

    If you're still really afraid of light killing it, perform this whole operation in the dark while wearing an aluminum suit to stop the infrared radiation from your overly excited body from exciting vibrational modes of the molecular bonds in the essential oils ... and take pictures (with no flash). I want to see if you really do this. Spend less time obsessing about wavelengths and go "catch a wave" down at one of those awesome beaches you folks have in Southwestern Turkey. There's a reason the German tourists love it down there so much. Go discover it ... and wear your best oud.

  11. #11
    Dependent
    Astaroth's Avatar
    Join Date
    May 2008
    Location
    West Los Angeles
    Posts
    2,017

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by irish View Post
    We all have to do sacrifices in the name of science.
    I'm having a moment over here, getting all weepy ...

  12. #12
    Cow Tipper Extraordinaire

    kbe's Avatar
    Join Date
    Nov 2006
    Location
    The Big Blue Marble
    Posts
    20,910
    Blog Entries
    1

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by Dimitrios View Post
    Moonlight is really good for them .... seriously !!
    Moonlight is what is referred to as "coherent light", reflected from a single source, the sun.

    Interesting read is by Lawrence Blair. His Rhythms of Vision has a section on speculation that coherent light can actually bend straight the chaotic individual atomic structure of the edge of a dulled razor blade, thus 're-sharpening' it to some extent.
    These things cannot be long hidden: the Sun, the Moon, the Truth--Buddha
    Currently wearing: Cumming by Alan Cumming

  13. #13
    Asha's Avatar
    Join Date
    Jan 2008
    Location
    Los Angeles
    Posts
    5,421

    Default Re: Wavelengths of light, and respective degredation...

    My area is optics (a specialty area of physics which concerns the behavior of light). And in my previous life, I also studied and practiced art conservation.

    I agree with the explanations and suggestions made here--light and heat will degrade the materials in perfumes (and paint pigments, etc.). Many atoms/molecules fluoresce, and this process will eventually cause "bleaching" of the component which was activated by the specific frequency. I would also say that the incorrect humidity and oxidation are also factors, but in a sealed perfume bottle, this is less of an issue (unless it has a lot of air space inside which is taken in from the spray nozzle during use).

    I would like to add one thing to the discussion about the EM spectrum:

    MOST glasses do not transmit appreciably in the UV spectrum, but they do transmit in the visible and near infrared to a great degree. Plastics transmit very broad band, including UV.

  14. #14
    Asha's Avatar
    Join Date
    Jan 2008
    Location
    Los Angeles
    Posts
    5,421

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by kbe View Post
    Moonlight is what is referred to as "coherent light", reflected from a single source, the sun.

    Interesting read is by Lawrence Blair. His Rhythms of Vision has a section on speculation that coherent light can actually bend straight the chaotic individual atomic structure of the edge of a dulled razor blade, thus 're-sharpening' it to some extent.
    But the sun is a broadband source and the moon essentially scatters the photons...so this is not really a coherent source. However, if you are talking about stars--while they are also broadband, in an optical system, they behave similarly to laser light when viewed. This is due to their great distance more than anything. In essence they are point sources.

    Coherence is a very complicated concept--one of the icons in the field is Emil Wolf, although his work is not great for bed-time reading
    Last edited by Asha; 21st July 2008 at 01:55 PM.

  15. #15
    Moderator

    Redneck Perfumisto's Avatar
    Join Date
    Feb 2008
    Location
    Spiritually, Kansas
    Posts
    13,379
    Blog Entries
    37

    Default Re: Wavelengths of light, and respective degredation...

    Well, I did a lot of looking, and couldn't find much info about specific chemistry of perfume decomposition. Only two things. (Just to explain why I didn't find more of this stuff - I can't use my usual sources, since this ain't work-related).

    I found one case where a natural frag chemical (guaiazulene, in blue chamomile) in a sunscreen was exposed to artificial sunlight for 3 hours (including both UVA and UVB), and the content of guaiazulene in the sunscreen was reduced to only 21% of the original amount! Meaning almost 80% was destroyed in just 3 hours of direct sun, even in the presence of UV-absorbing substances, and boo-koo of them. Ouch!

    The other thing I found is actually very helpful, but it's not about frags, per se. It's about the fragrance of beer (sorry about that, Dullah, but beer does appear to be useful for something - in this case helping us to understand frags! ). I turns out that the chemistry of "skunky" beer has been a mystery for many years, but the final answer wasn't found until fairly recently. I won't get too deep in the chemistry, because it's pretty complicated. But the lowdown is that:

    1) Skunky beer comes from small amounts of sulfur-containing compounds which are formed due to light exposure.

    2) It happens due to visible light, not UV.

    3) It happens with clear or even green glass, but is diminished by amber glass.

    4) The basic mechanism is that a substance other than the fragrance chemicals themselves absorbs the light, and that substance is the bad actor that starts everything. The fragrance chemicals are never themselves electronically excited by the light, which in their case would have to be UV. In the case of beer, the bad actor is riboflavin.

    5) The substance that does absorb the (visible) light then steals an electron from the fragrance chemicals, and that starts a path which not only eats up the fragrance chemical, but also creates a new, stinky one.

    6) The implications for frags are: (a) glass can mostly stop UV, but your frags are still at risk for sunlight damage by visible light, unless they are in dark or opaque glass (as Astaroth said). (b) although UV normally does more damage per photon, it is the specific frequency activating whatever bad stuff is actually possible that is the most dangerous, and (c) whatever happens depends markedly on the total mix of substances which are present in the juice, and what bad things are possible given that mix.

    But in any case, I would agree that we have to be careful not to get too retentive about our frags. Cool and dark is good, the more, the better, but not so much that it gets in the way of enjoying your frags. Which is why Luca Turin apparently just sticks his on a shelf where he can see them!

    Now, still, I do like Irish's suggestion about actually demonstrating what can happen (even if he was only trying to scam us out of our good stuff! ), so I'd like to do some kind of home experimentation, sorta like a Great Internet Perfume Skank-Off. We can get pictures and scent reports on pairs (or greater) of vials, one a control, and the other(s) subjected to various skank-inducing conditions. Not exactly hardcore science, but we can't exactly afford to buy a GC-MS on Grant's spare server change. Still we can do some simple bathroom science that's kinda fun, and will definitely give us a feeling for the magnitude of this thing.

    So what I'm saying is that we should stop simply whining about those frags we don't like, and actually get a bit medieval on 'em! Whaddaya say, people? <evil scientist laughter>Bwah-ha-ha-ha-ha!</evil scientist laughter>. Who's with me? <signature revoked below/>
    * * * *

  16. #16
    Dependent
    Astaroth's Avatar
    Join Date
    May 2008
    Location
    West Los Angeles
    Posts
    2,017

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by Redneck Perfumisto View Post
    The implications for frags are: (a) glass can mostly stop UV, but your frags are still at risk for sunlight damage by visible light, unless they are in dark or opaque glass (as Astaroth said). (b) although UV normally does more damage per photon, it is the specific frequency activating whatever bad stuff is actually possible that is the most dangerous, and (c) whatever happens depends markedly on the total mix of substances which are present in the juice, and what bad things are possible given that mix.
    The easiest way to stop all light from hitting your fragrances is to wrap them in metal foil, which prevents transmission of infrared, visible, and ultraviolet light. (It's nice that the Fermi Sea is really there when you need it. ) If you really want to still be able to look at your bottles, take a high resolution photo of them and paste it on the outside of the foil container (sort of like those screensavers of fish swimming in an aquarium).

  17. #17
    Asha's Avatar
    Join Date
    Jan 2008
    Location
    Los Angeles
    Posts
    5,421

    Default Re: Wavelengths of light, and respective degredation...

    Great post, RedneckPerfumisto. Something similar happens in paper--light, moisture, atmopheric acids and heat activate lignin contained inside the paper (paper is formed by cellulose pulp, often wood). The lignin reacts with the environmental factors and causes the hydrogen bonds in the paper structure to break down, making the sheet much more brittle. It also turns the paper yellow-brown due to Sulfur content of the acidic contaminant.

    I suppose this is why perfumes with more naturals go bad relatively easily--they have more impurities which degrade the scent when they recombine to form new molecules.

    How did you find out that aromachemicals respond mostly to UV? I have seen research about painting pigments and dyes that fluoresce, but I think the activation spectrum band varies based on the substance.

  18. #18

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by Asha View Post
    I suppose this is why perfumes with more naturals go bad relatively easily--they have more impurities which degrade the scent when they recombine to form new molecules.
    This may be the answer to the "Creed Lot Number" question that I posted earlier. Naturals degrade faster, in the bottle and on the skin, due to their unstable nature/impurities. Sounds reasonable.
    Last edited by Kevin Guyer; 23rd July 2008 at 05:31 AM.

  19. #19
    Moderator

    Redneck Perfumisto's Avatar
    Join Date
    Feb 2008
    Location
    Spiritually, Kansas
    Posts
    13,379
    Blog Entries
    37

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by Asha View Post
    How did you find out that aromachemicals respond mostly to UV? I have seen research about painting pigments and dyes that fluoresce, but I think the activation spectrum band varies based on the substance.
    Actually, that's just my own conclusion based on two unrelated observations. (1) I now have several books on aroma chemicals, plus my previous books on common organics, which included aroma chemicals. It turns out that the vast majority of these are either benzenoid aromatics or aliphatics with minimal unsaturation - typically one isolated or two conjugated double bonds, maximum. Consistent with this, they're almost all colorless solids or liquids, clearly absorbing very little in the visible region. (2) Most of my work was with things which did absorb in the visble region, and which have higher levels of conjugation. Generally speaking, even these absorbed mostly in the UV. But their lowest energy transitions were clearly tailed into the visible. We studied the electronic transitions of these puppies, and I had to do a bunch of calculations. Anyway, based on the structures of the aroma chems in my books, they should have their lowest electronic transitions in the UV. It's only the more highly conjugated ones that should have transitions in the visible. And, I should add, most fragrance chems are (in a structural sense) very similar to the ones that give beer its flavor. These were noted specifically by the authors as not having transitions in the visible region, which is part of what made it all a mystery. It wasn't until the role of riboflavin was postulated that things started to make sense in the case of beer photodecomposition.
    * * * *

  20. #20
    Moderator

    Redneck Perfumisto's Avatar
    Join Date
    Feb 2008
    Location
    Spiritually, Kansas
    Posts
    13,379
    Blog Entries
    37

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by Asha View Post
    I suppose this is why perfumes with more naturals go bad relatively easily--they have more impurities which degrade the scent when they recombine to form new molecules.
    Quote Originally Posted by Ruggles View Post
    This may be the answer to the "Creed Lot Number" question that I posted earlier. Naturals degrade faster, in the bottle and on the skin, due to their unstable nature/impurities. Sounds reasonable.
    Yes, it makes sense. Most natural oils that we were using in our recent project clearly have components absorbing in the visible region. Larger samples that I have ordered or looked at online are almost always shipped in amber glass, and the really big ones come in aluminum bottles. Such oils have an excellent chance of introducing one or more substances, absorbing in the visible region, which are capable of electron transfers, photooxidations, etc., after absorption. I would expect that the darker the natural oils and the lighter the glass, the more at risk the fragrance is.

    It's great when science works!
    * * * *

  21. #21

    Default Re: Wavelengths of light, and respective degredation...

    I'm too lazy to get out my photochemistry text, but here's my 2c worth:

    Short wavelength/high frequency EM radiation such as UV has sufficient energy to create free radicals, which are highly reactive chemical species. These can then attack other molecules, living or dead (I'll get to that in a second), causing chemical decomposition to occur. I presume the free radical can also be formed from the fragrance molecule itself, in which case it might break apart on its own or react with something else, but more likey the radical is formed from oxygen present in the bottle or from ethanol, which is the major constituent in perfume. Radicals are implicated in causing cancer, aging of skin, and other nasty things. Many perfume molecules, especially natural products, are big, hetero-functional molecules that are highly susceptible to attack by free radicals, so it's not surprising that light would cause damage, even if only a few percent of incoming UV radiation were to pass through the glass.

    p.s. Moonlight is NOT coherent. Coherency is a specific term used in laser optics to define light in which the peaks and valleys of the light waves are oriented the same way in space (all the waves "rise and fall" at the same time, to put it simplistically). As said before, moonlight is merely reflected white light. [Later: disregard what I wrote about coherence. Upon further checking, I realize there's more to the subject than I thought. However, I'm still pretty sure that moonlight is not coherent...]
    Last edited by Snafoo; 23rd July 2008 at 04:21 PM.
    Everyone is entitled to his own opinions, but not his own facts. Daniel Moynihan

  22. #22
    Asha's Avatar
    Join Date
    Jan 2008
    Location
    Los Angeles
    Posts
    5,421

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by Snafoo View Post
    I'm too lazy to get out my photochemistry text, but here's my 2c worth:

    p.s. Moonlight is NOT coherent. Coherency is a specific term used in laser optics to define light in which the peaks and valleys of the light waves are oriented the same way in space (all the waves "rise and fall" at the same time, to put it simplistically). As said before, moonlight is merely reflected white light. [Later: disregard what I wrote about coherence. Upon further checking, I realize there's more to the subject than I thought. However, I'm still pretty sure that moonlight is not coherent...]
    Snafoo, you are right--the application to lasers is only one part of coherence. It is possible to have coherent behavior in an optical system with white light, but specific conditions in the optical design must be present. Also, coherence has both spatial and temporal components. With the white light coherent system, the spatial portion is what is important as there is a "coherence volume" within which the light has coherent behavior. Also, as I previously mentioned, the "point source" quality of distant stars is a special situation that causes some optical effects which we also see with coherent light sources.

    It can be confusing even to me, and it is part of my background!

    Anyway, lasers are also interesting, and the light has characteristics other than coherence that make it special. These include directionality and monochromaticity.

    Sorry, OT

  23. #23
    Dependent
    Astaroth's Avatar
    Join Date
    May 2008
    Location
    West Los Angeles
    Posts
    2,017

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by Redneck Perfumisto View Post
    Now, still, I do like Irish's suggestion about actually demonstrating what can happen (even if he was only trying to scam us out of our good stuff! ), so I'd like to do some kind of home experimentation, sorta like a Great Internet Perfume Skank-Off. We can get pictures and scent reports on pairs (or greater) of vials, one a control, and the other(s) subjected to various skank-inducing conditions.
    I can provide one data point here. I have a 125ml bottle of Polo Sport that apparently rolled under the seat of my car at some point last summer. It got stuck under there for almost a week, getting pushed up to 100 degF pretty frequently since my car was being parked in one of the hottest parts of the San Fernando Valley.

    I am still using the bottle today, and the week of baking it experienced last summer does not seem to have impacted the fragrance at all. It still has all its longevity too. I was all set to toss it out and buy a new bottle, but I didn't need to.

  24. #24

    Cool Re: Wavelengths of light, and respective degredation...

    Huh? Why be so pedantic?
    Last edited by yepyep; 24th July 2008 at 01:18 AM.

  25. #25

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by yepyep View Post
    Huh? Why be so pedantic?
    Why, because we're pedantophiles, of course!
    Last edited by Snafoo; 25th July 2008 at 04:43 AM.
    Everyone is entitled to his own opinions, but not his own facts. Daniel Moynihan

  26. #26

    Default Re: Wavelengths of light, and respective degredation...

    "Wavelengths of light, and respective degredation"...

    "That is just the sort of pendatry up with which I shall not put!"

  27. #27
    Cow Tipper Extraordinaire

    kbe's Avatar
    Join Date
    Nov 2006
    Location
    The Big Blue Marble
    Posts
    20,910
    Blog Entries
    1

    Default Re: Wavelengths of light, and respective degredation...

    I humbly bow to those with higher learning arcs when it comes to light and wavelengths :wave: and such photonish things . I shall write Mr. Lawrence Blair a scathing letter admonishing him to lighten up in his next tome.
    Last edited by kbe; 24th July 2008 at 02:22 AM.
    These things cannot be long hidden: the Sun, the Moon, the Truth--Buddha
    Currently wearing: Cumming by Alan Cumming

  28. #28
    Dependent
    Astaroth's Avatar
    Join Date
    May 2008
    Location
    West Los Angeles
    Posts
    2,017

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by yepyep View Post
    "Wavelengths of light, and respective degredation"...

    "That is just the sort of pendatry up with which I shall not put!"
    I'll participate in any thread involving degradation, respective or not.

  29. #29
    Asha's Avatar
    Join Date
    Jan 2008
    Location
    Los Angeles
    Posts
    5,421

    Default Re: Wavelengths of light, and respective degredation...

    Pedantic? I thought we were having a light discussion...

    LOL

    KBE, I am not sure about the author you refer to--perhaps he is a dedicated and serious scientist. Or, maybe he is an imaginative sort, but I think that is very enjoyable also. Pop-science or serious-science aside, I sure do miss the days when I could watch Star Trek and accept most of the tech-babble....
    Last edited by Asha; 24th July 2008 at 02:51 AM.

  30. #30

    Default Re: Wavelengths of light, and respective degredation...

    Quote Originally Posted by moon_fish View Post
    Two things to add:
    I believe that there`s a reference-book of absorption spectrum for every aroma-chemical (lactones, aldehydes, terpenes, esters, patented synthetic molecules, etc.), so it could be easily found in physics or chemistry library (for patented - in those Givaudan, Takasago, etc).
    The CRC Handbook of Chemistry and Physics has many tables of absorbtion data but it is rather technical, and a good background in chemistry or physics is handy to get the most from this text. The Merck Index also has good information, that is a little less technical, plus it has an index of common names of many chemicals.

    Overall though moon_fish's answer is a good summation. Each compound will react to light differently due to things like type of molecule, the types of bonds, the bond angle, and other intra and intermolecular factors will cause each compound to react in a certain manner so there is no one answer to your question.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  



Loving perfume on the Internet since 2000