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].

Filter by
Sorted by
Tagged with
0
votes
0answers
37 views

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, ...
0
votes
0answers
38 views

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 ...
2
votes
0answers
56 views

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. ...
3
votes
0answers
53 views

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 ...
4
votes
2answers
88 views

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 ...
1
vote
0answers
75 views

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 ...
1
vote
1answer
81 views

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 ...
2
votes
1answer
74 views

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 ...
1
vote
1answer
38 views

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 ...
0
votes
1answer
57 views

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 ...
0
votes
3answers
148 views

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 ...
0
votes
1answer
271 views

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 ...
0
votes
1answer
82 views

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 e.g we study in steam distillation we reduce the external pressure on the compound to be ...
0
votes
0answers
37 views

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 ...
3
votes
1answer
71 views

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 ...
1
vote
3answers
128 views

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 ...
1
vote
2answers
161 views

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 ...
5
votes
3answers
1k views

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 ...
2
votes
0answers
332 views

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 ...
0
votes
1answer
49 views

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 ...
2
votes
2answers
166 views

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 ...
0
votes
0answers
140 views

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 ...
2
votes
1answer
105 views

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 ...
3
votes
0answers
295 views

The most convenient process to purify Oxalic Acid up to a high level of purity

I am set out to purify a batch of commercial oxalic acid with the aim in mind to end up with a highly pure product (starting from $\pu{4,000 ppm}$ total impurities and doing so with basic lab ...
0
votes
0answers
80 views

Drying sodium tetraborate for use as a standard

I am currently attempting to purify technical grade sodium tetraborate decahydrate by recrystallization for use as a titration standard. I don't have a requirement for a specific grade or purity. I'm ...
0
votes
1answer
105 views

How can I purify Ferric or Ferrous acetate with a very basic lab?

I’ve been trying to make Ferric acetate by mixing vinegar with steel wool and allowing it to react. The result is successful in dying leather or wood black and acting as a mordant. Theoretically there ...
4
votes
0answers
288 views

How can should one separate and purify benzophenone from salicylic acid?

I am working with two solids and I know that they are benzophenone (s)(ketone) and salicylic acid (s) (carboxylic acid). I am curious to know what is/are the best method of extraction and ...
4
votes
1answer
164 views

Purification of primary amines using Schiff base immobilization

I want to purify all primary amines containing compounds in a complex mixture (cell-extracted metabolites). I'm unaware of any published methods to do so. So I am thinking of making my own using a ...
0
votes
1answer
43 views

Using charcoal to clean water [closed]

I have read about charcoal being used to clean water before it is then boiled or mixed with a UV light stick. I have some questions about this: 1) Does it have to be activated charcoal? 2) Can ...
1
vote
2answers
551 views

Can separated and purified substances be obtained from a chromatogram?

I am studying chemistry, and I am learning about chromatography. But I am confused about how chromatography is used to ‘separate and purify’ substances. I have learnt about chromatography paper, ...
1
vote
0answers
24 views

Extraction Techniques for Organic Compounds from Aqueous Media

I am looking to attempt an extraction of an organic compound that had just been prepared using a Friedel-Crafts acylation. The compound was prepared in MDC (~20 mL in total). After the reaction, the ...
1
vote
1answer
95 views

What is Meant by "Eluting with 1-2% EtOAc/pentane" in Terms of Flash Chromatography?

I am reading the experimental section of a paper, and it states [compound of interest] Isolated as a pale yellow oil after flash chromatography on silica gel, eluting with 1-2% EtOAc/pentane... ...
2
votes
1answer
92 views

Can we use HPLC to purify an organic reaction product?

I know HPLC is a form of column chromatography that uses high pressure to pump a sample mixture/eluent through a column. However, I'm not sure if this technique is being used to purify and isolate ...
1
vote
0answers
29 views

How to convert pepsin into powder form?

I have pepsin powder which is now hydrated due to humidity. I want to convert it back to the powder form. How to do it? I don't have access to a freeze-dryer . I prefer any cheap procedure other than ...
1
vote
1answer
72 views

Electrolytic refining of precious metals — why the anode rather than the cathode? [closed]

In electrolytic refining, metals like platinum and gold are deposited as anode mud. Why aren't they deposited on the cathode since they have higher reduction potential?
1
vote
1answer
168 views

Concentrating sulfuric acid

Since calcium oxalate is 3000 times less soluble than calcium sulfate, would it be possible to concentrate sulfuric acid from let's say $\pu{50\%}$ solution using following steps? : adding calcium ...
-1
votes
1answer
41 views

How should I interpret and present my total protein amount? [closed]

I have a problem. I have purified a protein with method A and then B. After method A I have a protein concentration of 20 mg/ml and after method B a concentration of 18 mg/ml. Method B is dialysis and ...
1
vote
0answers
22 views

Choice of buffer pH to avoid aggregation

I want to purify IgG which has a theoretical pI of 6.4-9.0 with an anion exchange column. I also want to keep the pH of my buffers as low as possible and "outside" the range of the pI to prevent ...
1
vote
0answers
32 views

Change buffer in dialysis?

I have a protein that I purified in PBS buffer, pH 7. I will do dialysis to remove salt and will then further purify the protein with ion exchange chromatography. I will need to use another buffer (...
3
votes
1answer
143 views

How to conveniently separate Cd impurities from ZnO without contaminating it?

How could I separate Cd impurities from ZnO without contaminating it and without using overly expensive equipment or extremely dangerous solvents? I don't want to contaminate it by introducing other ...
-1
votes
1answer
671 views

Would dissolving Mg in NH3 help me purify Mg from all elements other than Li, Na, K, Rb, Cs, Fr, Ca, Sr, Ba, Eu and Yb? [closed]

According to Wikipedia all of the alkali metals, as well as $\ce{Ca, Sr, Ba, Eu,}$ and $\ce{Yb}$ (also $\ce{Mg}$ using an electrolytic process[4]), dissolve in ammonia to give the characteristic blue ...
3
votes
1answer
310 views

How do I remove tetrabutylammonium perchlorate from an organic synthesis?

I am trying to remove tetrabutylammonium perchlorate (TBAP) from an organic synthesis where TBAP was used as an electrolyte. I am working with compounds containing the amide group. I have used flash ...
1
vote
1answer
610 views

In HPLC, how does column diameter affect the retention time?

I am using a smaller diameter column than my previous one keeping all other factors such as stationary phase, solvent, solvent gradient constant. (Obviously, flow rate will be less in smaller column). ...
0
votes
0answers
453 views

Remove ethanol from gasoline by mixing it with water?

I have read on forums that ethanol can be removed from commercial gasoline by mixing it with water, then draining water from the bottom to remove the water-ethanol solution (for example, with a ...
1
vote
0answers
38 views

What zeolite types are typically used to absorb CO and CO2 gases at maximum zeolite absorption temperature?

Me and my friends are doing a project involving carbon monoxide and carbon dioxide as products to be filtered, we are using zeolites and would like to know the zeolite type typically used to filter $\...
3
votes
3answers
1k views

Is there a method to separate iron from mercury?

The mercury is contaminated with iron. Is there any way to remove iron from mercury?
2
votes
1answer
378 views

Techniques to extract lipids

I am planning an experiment on how to isolate casein and part of the process involves removing any lipids that may still be in it after filtering the precipitated casein out of the milk. I have read ...
6
votes
2answers
2k views

Recrystallisation of dibenzylideneacetone

Recently, I carried out the synthesis of dibenzylideneacetone. I had a lot of problems with the purification process, especially the part involving recrystallisation. I was instructed to carry out the ...
4
votes
2answers
712 views

Shea Stearin Extraction by Dry Fractionation

I have been able fractionate palm oil and extract palm stearin using the following method: Melt the palm oil (over 80 °C) Keep the melted oil at 33.5 °C for 24 hours (using an immersion circulated ...
2
votes
1answer
13k views

When using a "dilute hydrochloric acid" solution, how diluted should it be?

Quite often when reading through some instructions or documentation or an outline that I've found online (EG: acid-base extractions), theres a step that involves using a "dilute hydrochloric acid ...