Register to reply

Quantum Yield Determination

by amattiol
Tags: determination, quantum, yield
Share this thread:
amattiol
#1
Jan31-14, 08:57 AM
P: 8
Hello,
I have been measuring quantum yields in the lab for quite some time and have occasionally been running into some difficulty with my fluorescence spectra. The intensity (CPS) of the spectra for the same molecule will remain the same under the same conditions most of the time; then, every now and then it will be an order or two of magnitude lower. This obviously results very poor quantum yields, that are not even close to where they should be.

What I am wondering is what might be going on. The solvent is always the same, slit widths the same, excitation the same (though it shouldn't matter).

Could it be a bad blank?
Any suggestions would be greatly appreciated!

Also, I should note, when plotting the ∫ of fluorescence spectra vs UV-vis abs, the result is a near perfect linear relationship... as it should be; this makes me believe sample prep is not the culprit.
Phys.Org News Partner Chemistry news on Phys.org
Faster, cheaper tests for sickle cell disease
Simulations for better transparent oxide layers
Characterizing strontium ruthenate crystals for electrochemical applications
DrDu
#2
Jan31-14, 12:42 PM
Sci Advisor
P: 3,596
Maybe this is "blinking":
http://en.wikipedia.org/wiki/Fluorescence_intermittency


Register to reply

Related Discussions
Yield stress from tensile test and yield stress from hardness tests Mechanical Engineering 1
Naphtalene solid state Quantum Yield Chemistry 2
Quantum Yield Measurement Materials & Chemical Engineering 0
Quantum Yield Chemistry 1
Theoretical Yield, Molar Mass, and Percent Yield Biology, Chemistry & Other Homework 1