Questions tagged [purification]
For questions about purification - the process of rendering something pure, clean of foreign or undesired elements. Not to be confused with [metallurgy] or [chromatography].
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Why is kerosene being used in PUREX (plutonium uranium reduction extraction) as a solvent?
I am searching for a reason, why organic solvent in PUREX consists of 30% tributyl phosphate (TBP) in kerosene. Why kerosene (or another hydrocarbon)? What properties does it have? What exactly does ...
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Choice of nonsolvent in polymer purification by reprecipitation
Recently, I have synthesized new polymer. To purify the polymer, I tried reprecipitation. Because general nonsolvent is methanol, I dissolved the polymer in dichloromethane and reprecipitated into ...
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How to separate the salts within homemade sea salt
Goals
There are a few things that I'm looking to do:
Separate salt from seawater via some evaporation technique.
Separate the each of the major salts from the resulting sea water to get each into ...
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Is there some other way to perform fractional distillation without using Vigreux Column?
So recently I was performing an esterification reaction of oils like peanut oil or any neutral oil where I got some products which are only possible to filter using fractional distillation. I already ...
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Destination of carbonyl compounds free toluene
I am currently in the process of trying to get toluene free of carbonyl compounds using a distillation processes with DNPH.
Unfortunately I am no distillation expert. And am running into some problems....
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Removing Copper from drinking water by Electrolysis? What to keep in mind?
The drinking water in my flat contains a lot of copper. Although the amount of copper is around the allowed limit 2mg/l I would prefer to reduce it.
I know that it is at this value from a paid ...
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Air purifier: What is the reaction mechanism between HCHO and negative oxygen ion
Multiple government and commercial sources claim that the negative oxygen ion generated by air purifier can reduce HCHO concentration.
However, on google scholar, I find neither the reaction formula ...
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How to remove hydrofluorosilicic acid from water?
I'd like to come as close as possible to pure water. Would a KF filter remove hydrofluorosilicic acid? If not, what would?
I could not find the concentration of hydrofluorosilicic acid, but would like ...
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Polymer purification by reprecipitation troubleshooting
I am synthesizing new polymer that has not been reported before. The structure of the polymer is based on indacenodithienothiophene unit and thiophene. I used Stille polymerization. As monomers, I ...
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Would it make sense to filter air through oil?
I have seen water-based air purifiers, which work by having air bubble through water supposedly leaving water-soluble molecules behind.
I understand that this concept also humidifies the air due to ...
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Mixture is eluted too early from alumina in flash column chromatography
I have recently tried to purify my reaction mixture by column chromatography. Because my reaction mixture had poor resolution in silica-based TLC, I used neutral alumina-based TLC plate. After I ...
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A new green method for purifying acetylene with the help of Zeolite molecular sieve
I'm investigating for a green method for purification of acetylene in order to reduce the environmental impacts in manufacturing plants. In the current method mercuric chloride is used in the ...
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Recovery of precipitated polymer
I have recently newly synthesized the polymer. Based on its structure I tried to precipitate its concentrated solution in dichloromethane by dropping it into methanol. It seemed to work. The methanol ...
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What chemical reactions takes place in purifying acetylene?
Acetylene produced by water on calcium carbide method contain several impurity compound, that are harmful for welding or other purposes of acetylene and needs to be absorbed from the gas mixture ...
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What are good ways to anticipate co-crystalization of different metal ions?
What rationale (purely theoretical/assumptive, or known by experience / backed by evidence) would you use in an attempt to effectively anticipate which other metal or elemental ions are most likely to ...
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Why is desalination waste usually disposed back into the sea instead of converting it into chemical products?
I was reading about the desalination processes such as reverse osmosis and capacitive deionization and their alternatives. They all work on removing ions from water and disposing them back to sea/...
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Activating alumina before column chromatography
Recently I synthesized some amine compounds, and because it showed better separation in the neutral alumina TLC plates than silica plates, I am planning to purify the reaction mixture using neutral ...
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Evaporation of sample solvent and redissolving
When I conduct a synthesis, after some workups, I usually evaporate large amount of solvent using rotovap, recover compounds sticked to the wall of the flask to the glass vial using small amount of ...
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Purifying ferrous sulfate
For my wood staining experiments I have purchased 1 kilo of ferrous sulphate as a source of iron(II). It turned to be quite oxidised (yellowish) and the its solution is muddy yellow instead of green. ...
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Why is NMP developing a yellow color after distillation?
I got an aqueous mother liquor of N-methyl-2-pyrrolidone (NMP) from some reaction I was running and when I redistilled it under vacuum, it came out colorless but turned yellow the next day. I am ...
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Fragmentation behavior of spots in TLC
I tested multiple development using eluent condition hexane + 1% of ethyl acetate. Then I observed kind of fragmentation of spot.
I'm not sure, but I guess that successive spots are from the skyblue ...
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Using neutral or basic alumina in column chromatography for purification of amines
I am conducting a synthesis involving amines, and it is found that some spots still hardly moves from the starting point in spite of the dichloromethane 9:methanol 1 eluent condition. Addition of ...
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Reaction Workup and Quenching
In the supporting information of synthetic paper by Buchwald's group, They use 2-MeTHF as solvent (See B. General Procedures for Amination part, page 8). After the reaction ends and cools the mixture ...
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How can I determine the purity of an oligonucleotide solution?
After desalting an oligonucleotide via gel chromatography, I am left with (presumably) an oligonucleotide substance suspended in a buffer. What is the simplest way to verify the oligonucleotide's ...
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Water vapor permeation to the reaction flask
I am conducting a synthesis involving Buchwald-Hartwig coupling. The scale is $\approx10^{-4}$ mols of reagents. After running the reaction at 80 ℃ during 24 hours I found that sealing between the 3-...
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How does ethanol separates salts from proteins [closed]
Grad student here messing around with famed TRIzol isolation protocol and looking to optimize the protein yield at the end. There are more direct ways to get protein from a sample but I like getting ...
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The use of far-infrared ceramics for water purification?
I am struggling to understand how exactly far infrared ceramic balls help purify the water. It is stated that active ceramic taormine balls help purify the water by forming a 2 micrometer wavelength ...
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Cleaning used frying oil with salt water : what is the point of using salt?
In the process of making soap from used frying oil, I need to purify the oil.
I filtered the cooking oil but I also want to remove the polar compounds that are formed during frying : free fatty acids, ...
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If I have an oil that contains an impurity that's more soluble in water than in oil, is there a way to "wash out" the impurity with water?
Maybe this question is better classified as "physics" than chemistry, but I'm trying it here. Suppose I'm concerned about a substance S that is highly soluble in water and less soluble in ...
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Analysis of reaction mixture by TLC and finding column chromatography condition
I am conducting an organic synthesis. Below is the TLC image.
I used dichloromethane:methanol:triethylamine=10:1:0.15 as eluent, but I stored it during 3 days, so it may be a little bit concentrated.
...
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Purification of Buchwald-Hartwig amination
I am conducting a synthesis involving Buchwald-Hartwig amination. I use $\ce{Pd2(dba)3}$, $\ce{P(o-tol)3}$, and $\ce{Et3N}$ as base. In many proposed mechanisms, they often omit the precatalyst. I ...
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Should I do solvent extraction for Buchwald–Hartwig amination?
I am conducting a synthesis involving Buchwald–Hartwig amination. Catalyst is $\ce{Pd2(dba)3},$ ligand is $\ce{P(o-tol)3},$ base is $\ce{Et3N},$ and solvent is toluene. Image below is the proposed ...
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Leakage during Celite filtration
I'm conducting a synthesis involving crown ether and Pd catalyst.
In many papers, prior to column chromatography, they filter crude mixture through a Celite pad.
I tried to, but leakage of Celite ...
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How can I filtrate Pd2(dba)3 and P(o-tol)3? (Celite filtration failed)
I am conducting an organic synthesis involving Stille coupling, using $\ce{Pd2(dba)3}$ and $\ce{P(o-tol)3}$ as catalysts. Reaction solvent is toluene in which the catalysts also dissolve. Many texts ...
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Is it possible to filter Stille catalysts using syringe filter?
I'm conducting an organic synthesis involving Stille coupling.
Stille coupling uses $\ce{Pd2(dba)3}$ and $\ce{P(o-tol)3}$ as catalysts.
Both catalysts dissolves in toluene which is the solvent of my ...
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Microfiltration for saturated solutions of highly hygroscopic compounds?
Is it possible to pass saturated solutions of compounds with very high solubility through filters with small pores (e.g. passing a saturated aqueous ZnCl2 solution at 90C through a 2mcm glassfiber ...
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Is it possible to functionalize silica gel as Activated Carbon can be? How?
Activated carbon and Silica gel both have a high surface area.
If I understand correctly it is possible to trap stuff inside activated charcoal pores to give it specific retention properties (by ...
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Doubt regarding steam distillation
According to my textbook, in steam distillation the liquid boils when the sum of vapor pressure due to the organic liquid and that due to water becomes equal to the atmospheric pressure. Why? I did ...
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What chemical could be used as carbon monoxide scrubber?
I am trying to produce nitrogen by passing air over a heated tube of coals. This leaves a mixture of $\ce{CO},$ $\ce{H2O}$ and $\ce{N2}.$ Only $\ce{CO}$ is unwanted in this case.
Could I use calcium ...
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Steam distillation vs fractional distillation
I am a high school student and I am a little confused in the techniques used to purify organic compounds. For example, in steam distillation we reduce the external pressure on the compound to be ...
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Related to liquid-liquid extraction
I was reading about purification of organic compounds and I came across this.
I quote below, a line from the excerpt that caused my confusion.
The organic solvent is later removed by distillation or ...
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How to separate copper(II) chloride from 4-iodophthalic anhydride?
I am planning a reaction in which I iodate phthalic anhydride. My reaction is I2, phthalic anhydride, and copper(II) chloride as a catalyst. The solvent is 99.9% isopropanol. How do I separate the ...
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Synthesis of anhydrous sodium tungstate
I am interested in preparing an anhydrous sample of sodium tungstate (Na2WO4), which is normally found as the dihydrate. Finding an example of this in literature is proving difficult, I am interested ...
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If stirring negatively affects crystal purity, why is it so?
My Intellectual Expectations
Intuitively, I would expect strong stirring to improve crystal purity during the process of crystalization. My rationale is that strong stirring would increase contact ...
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How to extract pure potassium carbonate from ash?
In our village, lots of ash is produced which is thrown off. I want to extract pure potassium carbonate from that ash. I am able to extract the potassium compound and a soluble compound by ...
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Purification of Red Phosphorus
The Boring Stuff
I'm well acquainted with various fields of science & engineering, but my foray into the world of chemistry is relatively recent.
I'm in a location (probably most of us are to some ...
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Reduction by Activated Carbon
Does reduction by carbon itself occur when filtration is performed using activated carbon? Is it part of the central mechanisms involved in activated carbon filtration?
One of the specificities of all ...
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Ways to determine the concentration of alkyl halides in organic solvents
I have a volatile alkenyl bromide dissolved in hexanes. I have to use the halide in a Grignard reaction but separating it from hexanes is hard (the bromide is light sensitive and very volatile). I ...
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How do you purify gases formed in electrolysis with a potassium hydroxide electrolyte?
I am interested in the $\ce{KOH}$ vapor that is released with my gasses during electrolysis.
I have two questions.
What would be the best place to start research on the $\ce{KOH}$ vapor produced in ...
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Is reverse osmosis a fancy term for filtration?
In Reverse Osmosis (RO) systems, the water to be purified is pushed against a semipermeable membrane and comes cleaner the other side, the path of water is the reverse of regular osmosis, hence the ...
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