June 01, 2024, 07:43:27 PM
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Analytical Chemistry Forum / Re: HOCL shelf life problem
« Last post by Borek on Today at 05:08:24 PM »
Acidifying the solution is a sure way of speeding up the decomposition.

Buffers composition is typically calculated using Henderson-Hasselbalch equation, see examples here: https://www.chembuddy.com/buffers-composition-calculation
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Analytical Chemistry Forum / Re: HOCL shelf life problem
« Last post by Hunter2 on Today at 03:49:18 PM »
Hydrochloric will destroy immediately to chlorine.
HOCl + HCl => H2O + Cl2
For cleaner it's better to have NaOCl not the acid.
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Organic Chemistry Forum / Re: Degradation of aspartame at pH 8
« Last post by rolnor on Today at 03:36:37 PM »
Ninhydrin is not good for this, make solutions in NMR tubes and run spektrum after the reaction time is up. Use D2O DCl and NaOD. Or monitor by HPLC
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Analytical Chemistry Forum / HOCL shelf life problem
« Last post by angzukofi on Today at 02:03:07 PM »
[Chemistry/Math problem at end]
I've been making homemade HOCL(hypochlorous acid) and it doesn't last very long. I've been trying to find a way to prolong the shelf life, beside the obvious store in opaque PET container away from direct sunlight. (which by the way I have it in a spray bottle... I don't think the straw or sprayer mouth is PET, does that matter?)
One potential solution is adding phosphoric acid to act as a preservative and at the same time lowing the pH to my desired pH.
Another is adding hydrochloric acid to lower the pH and then adding a phosphate buffer like sodium phosphate to act as the preservative.

Now my question is, which solution would leave me with a cleaner or more stable product, and how much of each product do I need to add?

Say I have 6 liters of HOCL at a 6 pH
how much mL phosphoric acid do I need to add (and does it need to be 85% phosphoric acid?) To stabilize it at 5 pH. (explanation and formula would be greatly helpful for my future reference to calculate myself)

Now say I have 6 liters of HOCL at 5 pH (thanks to the hydrochloric acid) (from advice another told me that phosphoric acid does not mix well with hydrochloric acid and should not be added but instead a phosphate buffer) how much sodium phosphate should I add to have the same preservative effects of phosphoric acid (and does that affect the pH?)

Can I do add multiple preservative steps to prolong the shelf life more without tampering the HOCL pH and ppm ?

Does anyone know a better way to preserve the pH for up to 2 years?
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Hey everyone, I am currently working on my Bachelor's thesis for which I am conducting an organic reaction. I am using TLC (with a "build-in" visualizer at 254nm UV) to monitor my reactions. As I am using N,n-dimethylformamide as a solvent in my reaction, I was wondering whether it would also show up on the TLC if I were to take a sample. Thanks for the help in advance!
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Lots of Delocalized electrons <=> solid at room temperature?

I am writing to figure out whether the fewer or absence of delocalized electrons in non-metals causes them to be non-solid at room temperature. Do I have all the reasons?
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Organic Chemistry Forum / Re: Degradation of aspartame at pH 8
« Last post by Corribus on Today at 11:21:27 AM »
I would also consider the possibility that the effectiveness of the ninhydrin test is pH-dependent, and the optimal pH is different for different amino acids, as shown in Lemothe and McCormick, Analytical Chemistry, 44(4), 1972, 821

https://pubs.acs.org/doi/pdf/10.1021/ac60312a003
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Citizen Chemist / Need help with new organic product
« Last post by eneny on Today at 09:56:15 AM »
Hi, we are developing a new organic surf wax that is eco friendly. Our main goal is to get rid of generic surf wax that pollute our ocean. We have perfected it but have a huge problem with the color. It is now a baby nappy brown and we need it to be white or colorless. The main ingredients are beeswax and coconut oil. We are trying our best to keep it organic but at the very least we want it echo friendly. We have tried: titanium oxide but it changes the consistency too much, peroxide but it doesn't change the color. Any suggestions?
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Analytical Chemistry Forum / Re: Advice on identifying drug in capsule
« Last post by Borek on Today at 08:39:35 AM »
There is no universal method, best approach typically depends on the identity of the active substance.
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My capsule likely contains 2 compounds, both in powder form. 1 is an excipient (aka filler) which should be cellulose, the second is a medicine. Each capsule contains, approximately, 300mg filler versus 15mg of medicine.

What chemical test should I run to confirm the presence of the medicine in the capsule? I was thinking of running a 1H NMR with chloroform as the solvent, but can it still be done given that the filler is insoluble in chloroform? I am thinking about getting the lab to dissolve it in chloroform and analyse the filtrate. How advisable is this, and what better alternatives are there?

I am asking this because I am worried that I got a bunk drug. I bought it from a chinese supplier because they were selling it for cheap. Name is Xian Sonwu, not sure how great their reputation is, but I originally trusted them since I saw that multiple researchers (with papers published to prestigious journals like nature) have bought and used their chemicals.
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