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hypervalent_iodine last won the day on October 31 2018

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About hypervalent_iodine

Profile Information

  • Interests
    Organic and medicinal chemistry
  • College Major/Degree
    Bachelor of Science (Hons I) - Chemistry
  • Favorite Area of Science
    Organic Chemistry
  • Occupation
    Ph.D. student

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  1. hypervalent_iodine

    Creative reaction for a volcano

    It won’t produce any gas AFIK, just calcium hydroxide and then calcium acetate. What’s wrong with just using baking soda and vinegar? You could add dry ice if you wanted a nice smokey effect.
  2. hypervalent_iodine

    'Stupid Woman'

    ! Moderator Note Once again, could we please get back on topic.
  3. hypervalent_iodine

    Lubricant detection in water

    Yes, those. I am not very familiar with them personally, but it seems like it would be workable for the OP. Thermo literature states that their current model can profile PEG quite well and quantify polyacrylic acid down to ppb levels in industrial cooling water samples.
  4. hypervalent_iodine

    Lubricant detection in water

    You can use use a Corona detector in tandem with HPLC, which would circumvent the need for a chromophore. Not sure if that would be cheaper than MS, but you’d need a decent amount of money either way I guess.
  5. hypervalent_iodine

    Lubricant detection in water

    It matters if it is a single compound if they want to measure it at ppm levels, as stated in the OP. Thank you for the tutorial in IR that you posted. As it happens, I use IR regularly, albeit for characterisation rather than quantification. In any case, I can’t for the life of me figure out why you have posted it here? It doesn’t refute anything that I have said wrt the suitability of IR for the OP’s stated intention. Moreover, I would like to add that you are unlikely to see alkene stretches in this instance. These peaks are typically very weak, and would likely be obfuscated by OH peaks (if present), and the myriad of other peaks in there that would be there in greater number and thus have much higher absorbance. I have to ask, why exactly are you being so stubborn on this point? You have been told by two people who work in chemistry that IR is not a good option in this instance, for the reasons stated. You stubborn insistence is confusing. I have in fact suggested another alternative, HPLC. You would need a particular type of detector to do it for these samples, but I cannot think of any other way to easily quantify aqueous solutions of PAG. @Mt21 you may also wish to ask your question at Chromatography Forum. It’s reasonably busy and has a lot of talented people there who specialise in quantification and the various pieces of equipment you might come across. I used to frequent there a lot when I worked in an analytical lab as a technician.
  6. hypervalent_iodine

    Lubricant detection in water

    I don't think you are understanding what I am saying. PAG is not one compound of a specific chemical formulae; it encompasses many, many possible compounds. IR wouldn't to be able to distinguish between these and as such, you cannot correlate the absorbance of any particular peak to concentration in the same manner as defined by Beer-Lambert, meaning you would not be able to accurately or precisely quantify it. So again, IR is a poor choice and would not suit the OP's needs, regardless of how often they need the testing done.
  7. hypervalent_iodine

    Lubricant detection in water

    It's interesting, but it still doesn't help the fact that IR would not be able to differentiate between the different types of PAG present, which would render any effort at quantification unreliable. Not to mention the undoubtedly huge cost of buying a dedicated machine from a company like Bruker.
  8. hypervalent_iodine

    Lubricant detection in water

    IR would be a poor choice. As mentioned, the water (a strong IR absorber) would obfuscate the spectra and make quantification very difficult (or impossible), especially if you’re talking about ppm concentrations in swimming pools. I don’t think GCMS is a great choice for a polymer either, as it would be too big and unlikely to run through the column. The other issue is that PAG is not one single compound. You could potentially do it with LC with the right set up and correct detector, but I am not 100% sure on this. This seems to suggest it’s possible, but I didn’t read it thoroughly.
  9. hypervalent_iodine

    Organic chemistry reaction scheme

    Where exactly do you need help and can you show what you have done so far?
  10. hypervalent_iodine

    'Stupid Woman'

    ! Moderator Note I suggest we return to the topic of the OP. If you wish to discuss sexism more broadly, you are welcome to open a new topic.
  11. hypervalent_iodine

    Quick Forum Questions

    That would be my guess. I had a look at a few of the accounts yesterday and they seem benign. Sometimes we do have spam accounts that registered years ago suddenly make an appearance, updating their profile with photos and spam links, but this does not seem to be the case here.
  12. hypervalent_iodine


    ! Moderator Note Welcome to SFN. Please note that this is a discussion forum and as such, threads should be posited with a view for continued dialogue amongst our members. As your OP offers no points for conversation, I am going to close this. You are welcome to post it as a status if you wish.
  13. hypervalent_iodine

    So Again as i was

    ! Moderator Note You've been given several chances with this content, and you have been asked not to bring it up again. If you do not stop, you will have your posting privileges revoked.
  14. hypervalent_iodine

    Antibiotics resistance

    Could you be more specific? Sulfanmides appears to be a typo, so can I assume you are talking about sulfonamides? If so, sulfonamides are some of the oldest antibiotics that saw widespread use. They went out of favour because of resistance. Of course, the term is very broad, so is there another type of sulfonamide, or other sulfa drug, that you are referring to?
  15. hypervalent_iodine

    Why is it hard to whistle with a dry mouth?

    The seal formed for dry vs wet is quite different I think. For brass, another factor is that have your lips lubricated allows you to move your mouth around the mouthpiece easier, which is crucial for several reasons such as creating different sounds / intonations, and hitting higher and lower notes. Couldn’t say if it’s the same for woodwind, but I’ve played brass most of my life.