Question
If I have a graph of concentration in Absorbance at 400nm vs [micromolar]of para-nitrophenol
The slope would be the extinction coefficient. (y=mx) if forced through 0
The problem is what is y?
I know y is the absorbance but it's given on a paper i have as, <b>y= Absorbance at lmax</b>
<b>Can someone explain what lmax means?</b>
I need to find the concentration of an unknown from this standard curve and I think I find it by first finding the epsilon from the graph, by using..
<b>1.</b> y=mx then:
m= # microM^-1 cm^-1
(not sure if it needs to be in M^-1 or how to convert it to that if I need it to be)
The m is the epsilon.
<b>The problem is that the graph's slope is 0.003653 is molar absorption coefficient supposed to be that small?</b>
<b>2.</b> then I take that and use it to find the concentration of the unknown solution, from beer's law, since I have the absorption of it.
<b>Another issue is that the sample I did measure, was of a solution that I diluted in a ration of 1ml sample to 3ml pH10 buffer. The standard curve sample of 0.1M Paranitrophenol was also diluted with buffer prior to being analyzed, with same ratio of dilution.</b>
First, finding the concentration of the diluted unknown is okay, as long as the absorption coefficient is right...by using A= ebc
A= known
e= calculated from graph above
c= concentration (can be found)
b= 1cm
<b>But how am I to find the original concentration of the unknown stock paranitrophenol if I did not analyze it and was not told to....instruction ssay to, "calculate the concentration of the diluted unknown Paranitrophenol and the original unknown stock paranitrophenol using the standard curve generated"</b>
The slope would be the extinction coefficient. (y=mx) if forced through 0
The problem is what is y?
I know y is the absorbance but it's given on a paper i have as, <b>y= Absorbance at lmax</b>
<b>Can someone explain what lmax means?</b>
I need to find the concentration of an unknown from this standard curve and I think I find it by first finding the epsilon from the graph, by using..
<b>1.</b> y=mx then:
m= # microM^-1 cm^-1
(not sure if it needs to be in M^-1 or how to convert it to that if I need it to be)
The m is the epsilon.
<b>The problem is that the graph's slope is 0.003653 is molar absorption coefficient supposed to be that small?</b>
<b>2.</b> then I take that and use it to find the concentration of the unknown solution, from beer's law, since I have the absorption of it.
<b>Another issue is that the sample I did measure, was of a solution that I diluted in a ration of 1ml sample to 3ml pH10 buffer. The standard curve sample of 0.1M Paranitrophenol was also diluted with buffer prior to being analyzed, with same ratio of dilution.</b>
First, finding the concentration of the diluted unknown is okay, as long as the absorption coefficient is right...by using A= ebc
A= known
e= calculated from graph above
c= concentration (can be found)
b= 1cm
<b>But how am I to find the original concentration of the unknown stock paranitrophenol if I did not analyze it and was not told to....instruction ssay to, "calculate the concentration of the diluted unknown Paranitrophenol and the original unknown stock paranitrophenol using the standard curve generated"</b>