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
1 answer
51 views

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. ...
user avatar
  • 111
1 vote
0 answers
48 views

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 ...
user avatar
  • 767
2 votes
0 answers
22 views

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 ...
user avatar
  • 767
-2 votes
2 answers
75 views

Isolating potassium chloride from sodium chloride and potassium hydroxide

Assume that you have an aqueous solution of sodium chloride and potassium hydroxide. Is it possible to isolate potassium chloride from this? I'm thinking about the following: Na+(aq) + Cl-(aq) + K+(aq)...
user avatar
1 vote
0 answers
24 views

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 ...
user avatar
  • 767
1 vote
0 answers
12 views

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 ...
user avatar
1 vote
1 answer
74 views

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-...
user avatar
  • 767
1 vote
0 answers
34 views

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 ...
user avatar
2 votes
0 answers
98 views

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 ...
user avatar
0 votes
0 answers
65 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, ...
user avatar
0 votes
0 answers
39 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 ...
user avatar
  • 9
2 votes
0 answers
64 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. ...
user avatar
  • 767
3 votes
0 answers
56 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 ...
user avatar
  • 767
4 votes
2 answers
108 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 ...
user avatar
  • 767
1 vote
0 answers
192 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 ...
user avatar
  • 767
2 votes
1 answer
108 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 ...
user avatar
  • 767
2 votes
1 answer
88 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 ...
user avatar
  • 767
1 vote
1 answer
39 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 ...
user avatar
  • 889
0 votes
1 answer
67 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 ...
user avatar
  • 889
-1 votes
3 answers
226 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 ...
user avatar
0 votes
1 answer
400 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 ...
user avatar
  • 1,450
0 votes
1 answer
111 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 ...
user avatar
0 votes
0 answers
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 ...
user avatar
  • 445
3 votes
1 answer
77 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 ...
user avatar
  • 321
1 vote
3 answers
150 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 ...
user avatar
1 vote
2 answers
273 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 ...
user avatar
  • 889
5 votes
3 answers
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 ...
user avatar
2 votes
0 answers
441 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 ...
user avatar
  • 159
0 votes
1 answer
55 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 ...
user avatar
  • 889
2 votes
2 answers
178 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 ...
user avatar
  • 1,281
0 votes
0 answers
181 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 ...
user avatar
2 votes
1 answer
113 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 ...
user avatar
  • 116
3 votes
0 answers
331 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 ...
user avatar
  • 889
0 votes
0 answers
95 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 ...
user avatar
  • 110
1 vote
1 answer
157 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 ...
user avatar
4 votes
0 answers
309 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 ...
user avatar
  • 71
5 votes
1 answer
190 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 ...
user avatar
0 votes
1 answer
60 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 ...
user avatar
1 vote
2 answers
689 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, ...
user avatar
1 vote
0 answers
28 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 ...
user avatar
  • 1,809
1 vote
1 answer
104 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... ...
user avatar
  • 1,809
2 votes
1 answer
102 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 ...
user avatar
  • 23
1 vote
0 answers
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 ...
user avatar
  • 49
1 vote
1 answer
79 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?
user avatar
1 vote
1 answer
194 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 ...
user avatar
  • 1,450
-1 votes
1 answer
42 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 ...
user avatar
  • 25
1 vote
0 answers
24 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 ...
user avatar
  • 29
1 vote
0 answers
34 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 (...
user avatar
  • 11
3 votes
1 answer
147 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 ...
user avatar
  • 433
-1 votes
1 answer
677 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 ...
user avatar
  • 433