Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Quantitative analysis of ketones
goldberg
Hazard to Self
**




Posts: 76
Registered: 28-4-2018
Member Is Offline

Mood: No Mood

[*] posted on 19-8-2020 at 08:15
Quantitative analysis of ketones


I'm looking for a way to determine concentration of ketone in aqueous solution(or water+ cosolvent system if given ketone is not water soluble).

I tried to search on the Web for information about tiration of ketones but i have only found Karl-Fisher method of determination of water in ketones.

With aldehydes i could to permanganometry to oxidize ketone to correspodning carboxylic acid.

I'm interested in general method but i'm especially interested in benzylic ketones(for example acetophenone and propiophenone).

Is it possible to titrate ketone? I do not have access to chromatography, which would solve this problem.

How about cyclic amperometry? In theory it is possible to electrochemically reduce ketone and measure current.
View user's profile View All Posts By User
macckone
International Hazard
*****




Posts: 1669
Registered: 1-3-2013
Location: Over a mile high
Member Is Offline

Mood: Electrical

[*] posted on 19-8-2020 at 09:06


The usual method would be to form an abduct with the ketone.
Sodium bisulfite will generally form an insoluble abduct.
MEK and Acetone are more soluble.

https://erowid.org/archive/rhodium/chemistry/eleusis/bisulfi...

View user's profile View All Posts By User
Bonee
Harmless
*




Posts: 13
Registered: 20-12-2010
Member Is Offline

Mood: No Mood

[*] posted on 20-8-2020 at 13:07


Sodium nitroprusside combined with a strong base gives a red coloured product if applied to methyl ketones.

https://en.wikipedia.org/wiki/Sodium_nitroprusside

View user's profile View All Posts By User
Dr.Bob
International Hazard
*****




Posts: 2205
Registered: 26-1-2011
Location: USA - NC
Member Is Offline

Mood: No Mood

[*] posted on 20-8-2020 at 16:02


Most ketones react with hydrazines to form imines/hydrazides, the typical one is dintrophenylhydrazine, which is a common test for ketones. Try googling "Quantitative analysis of ketones hydrazide" and you will find several refs.
View user's profile View All Posts By User
goldberg
Hazard to Self
**




Posts: 76
Registered: 28-4-2018
Member Is Offline

Mood: No Mood

[*] posted on 25-8-2020 at 08:31


@Dr.Bob Unfortunately i did not much about this method.
From i have read sodium nitroprusside can be used to detect ketones, but how about quantitative analysis?
Moreover this reaction is specyfic to methyl ketones and i need a general method.

How about electrochemical methods?
View user's profile View All Posts By User
DraconicAcid
International Hazard
*****




Posts: 3406
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline

Mood: Semi-victorious.

[*] posted on 25-8-2020 at 11:30


For quantitative methods, I can think of two. Gravimetric methods (make a semicarbazide or DNP derivative, and then weigh it), or colorimetry (make the nitroprusside derivative, and find its concentration by measuring its absorbance).



Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
View user's profile View All Posts By User
AvBaeyer
International Hazard
*****




Posts: 535
Registered: 25-2-2014
Location: CA
Member Is Offline

Mood: No Mood

[*] posted on 25-8-2020 at 15:27


Goldberg:

You should seek out the following book for help with your problem:

S. Sigia, "Quantitative Organic Analysis via Functional Groups," Wiley, New York, 1954, see p. 21

(Just checked ABEbooks site. Several editions of this book are available quite cheaply. Bought one myself.)

I have seen this work referenced regarding quantitative analysis of carbonyl compounds though I have not seen the book myself. The following book, which I own, has a good discussion of the problems associated with carbonyl group analysis:

J.S. Fritz and G.S. Hammond, "Quantitative Organic Analysis," John Wiley and Sons, New York, 1957, see preface and Chapter 2.

AvB

[Edited on 25-8-2020 by AvBaeyer]
View user's profile View All Posts By User
macckone
International Hazard
*****




Posts: 1669
Registered: 1-3-2013
Location: Over a mile high
Member Is Offline

Mood: Electrical

[*] posted on 25-8-2020 at 20:00


Quantitative Organic Analysis - Fritz and Hammond - Full view but not easily downloadable
https://babel.hathitrust.org/cgi/pt?id=mdp.39015003705269

Quantitative Organic Analysis via Functional Groups Sigia
https://archive.org/details/unset0000unse_e3d7

View user's profile View All Posts By User
goldberg
Hazard to Self
**




Posts: 76
Registered: 28-4-2018
Member Is Offline

Mood: No Mood

[*] posted on 28-8-2020 at 08:23


Thanks a lot. I'm reading Quantitative organic analysis via functional and this book gave me an answer.
View user's profile View All Posts By User

  Go To Top