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The reason for selection of wavelengths in the spectrophotometry of Quinoline Yellow SS
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+ Absorption
+ Chemistry
+ Spectrophotometry
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Malcolm Rahuaha
The reason for selection of wavelengths in the spectrophotometry of Quinoline Yellow SS
The experiment in your link pg 31 is "Path Length Dependence of Absorbance Values". As you stated, quinoline absorption spectrum has a dip near 337 nm. The reason for choosing the wavelength is not something fundamental. You already know that most sensitive analysis is carried out at the peak maximum rather than a wavelength corresponding to a valley. All Agilent wanted to show here is that Beer's law is valid for all wavelengths in the absorption spectrum, as long as A > 0.
If you are carrying out this experiment, check how the slopes vary with different path length and wavelengths. Are all the slopes the same?
The experiment in your link pg 31 is "Path Length Dependence of Absorbance Values". As you stated, quinoline absorption spectrum has a dip near 337 nm. The reason for choosing the wavelength is not something fundamental. You already know that most sensitive analysis is carried out at the peak maximum rather than a wavelength corresponding to a valley. All Agilent wanted to show here is that Beer's law is valid for all wavelengths in the absorption spectrum, as long as A > 0.
If you are carrying out this experiment, check how the slopes vary with different path length and wavelengths. Are all the slopes the same?
@StrugglingChemistryStudent, Yes! You got it right. In analytical chemistry, sensitivity is defined as the slope. Higher the slope, the more sensitive the analysis is.More
I graphed Absorbance vs Path length for the three wavelengths (224, 337 and 414nm). The slopes are similar for 224 and 414nm (the peaks), the slope is close to 0 for the trough, which doesnt seem useful. So just to clarify, the choice of the trough is simply to demonstrate that the linear relationship holds for all wavelengths?More
The experiment in your link pg 31 is "Path Length Dependence of Absorbance Values". As you stated, quinoline absorption spectrum has a dip near 337 nm. The reason for choosing the wavelength is not something fundamental. You already know that most sensitive analysis is carried out at the peak maximum rather than a wavelength corresponding to a valley. All Agilent wanted to show here is that Beer's law is valid for all wavelengths in the absorption spectrum, as long as A > 0.
If you are carrying out this experiment, check how the slopes vary with different path length and wavelengths. Are all the slopes the same?
The experiment in your link pg 31 is "Path Length Dependence of Absorbance Values". As you stated, quinoline absorption spectrum has a dip near 337 nm. The reason for choosing the wavelength is not something fundamental. You already know that most sensitive analysis is carried out at the peak maximum rather than a wavelength corresponding to a valley. All Agilent wanted to show here is that Beer's law is valid for all wavelengths in the absorption spectrum, as long as A > 0.
If you are carrying out this experiment, check how the slopes vary with different path length and wavelengths. Are all the slopes the same?
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