All Questions
Tagged with extraction analytical-chemistry
14
questions
-2
votes
1
answer
109
views
Performing the mean and standard deviation for a extraction based on averaged content determination
Is it okay to perform the mean and standard deviation for a triplicate extraction based on averaged values of content determination?
I performed an extraction in triplicate. Each one of the ...
- 43
3
votes
2
answers
121
views
Can I expect the same (or very close) peak areas from herbal extracts prepared with the same plant/solvent ratio?
I prepared an extract by using 100 mg of plant and 2 mL of ethanol, filtered and injected 20 μl into the HPLC system equipped with Waters® XSelect (150 mm × 4.6 mm, 5 μm) column. If I prepare an ...
- 43
2
votes
1
answer
79
views
How can over grinding lead to reduced API extraction in HPLC analysis?
I am looking for some advice regarding particle size distribution (PSD) & how this can be affected by grinding a tablet.
During an assay by HPLC, the method requires grinding of a tablet before ...
- 21
0
votes
2
answers
185
views
How to determine the iron content of a screw?
In Analytical Chemistry, I was asked to determine the iron content of a screw.
I thought it could be solved in the following way:
Treat the screw with a solution of sulfuric acid or hydrochloric ...
- 607
0
votes
0
answers
562
views
SPE recovery greater than 100%?
I am evaluating a paper Gan et. al. 2013 (https://doi.org/10.1016/j.chroma.2012.11.081) Table S4 (see image below) and I am focusing on evaluating the percent recovery for using different solid-phase ...
2
votes
0
answers
60
views
Increasing concentration of acetylcholine via SPE
I am trying to increase the final yield of acetylcholine (ACh) in my biofluid samples. I need to get the yield high enough for high confidence annotation of ACh (currently all I can really say is that ...
- 193
0
votes
0
answers
28
views
Procedure for determining the levels of Acrylamide from a cup of coffee
For experimental purposes, I want to determine the level of Acrylamide in cups of coffee. Is there a method that doesn't use spectrometric analysis to determine it as I do not have access to it in the ...
6
votes
1
answer
111
views
Distribution coeffecient without concentrations
From what I understand about distribution coefficient is straight from my book — which does not give any practice examples — is that
$$D = \frac{C_\mathrm{A}(\text{ext})}{C_\mathrm{A}(\text{orig})}$$ ...
- 71
1
vote
0
answers
67
views
What is the best way to illustrate the recovery of an extraction method?
I'm currently working on PFAS (perfluoroalkyl compounds) extraction from soils and their analysis by HPLC-MS/MS.
I wonder what kind of graph can be the best to illustrate the recovery of the method. ...
6
votes
1
answer
322
views
Folin–Ciocalteu formula
I am searching a long time now. I have a question about the Folin–Ciocalteu formula for quantification of polyphenol. How is the $62.5$ in the equation explained? Where does it come from?
This is the ...
- 69
5
votes
0
answers
159
views
Where is my antimony going?
I work in a trace metals laboratory operating an ICP-OES. I've been having some trouble with the recovery of antimony in a weak $\ce{HCl}$ solution post-digestion.
The antimony is part of a mix of ...
- 51
0
votes
1
answer
1k
views
How to calculate the cation exchange resin capacity?
If I have a cation exchange membrane and need to remove 2 g/L of sodium, how much resin would I need.
I used the amount of substance of $\ce{Na}$ to calculate the amount of substance of $\ce{SO3H-}$ ...
- 325
1
vote
1
answer
4k
views
Separation of Binary mixture?
I will be given a binary mixture containing two unknown compounds(the mixture could be either liquid or solid- I don't know yet). The plan of the experiment is to identify the two compounds. So my ...
- 567
5
votes
1
answer
448
views
Standard solution and extracted solution : same concentration?
Summary :
I am currently testing how a certain type of foam adsorbs HAP, PCB and OCP, and to this end I am depositing some on the foam, then extracting it. To know how much was extracted, I need to ...
- 61