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Why absorbance is decreased after maximum wavelength achieved?
Wiki User
∙ 11y ago
It must, of course!: - Because Lambdamax in a Wavelength-Range is defined this way!
Wiki User
∙ 11y ago
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Why do you use the wavelength with the maximum absorbance in spectroscopy?
Short answer:Using the maximum wavelength gives us the best results. This is because at the peak absorbance, the absobance strength of light will be at the highest and rate of change in absorbance with wavelength will be the smallest. Measurements made at the peak absorbance will have the smallest error.Long answer: It really depends on what is the largest source of error. Taking the readings at the peak maximum is best at low absorbance, because it gives the best signal-to-noise ratio, which improves the precision of measurement. If the dominant source of noise is photon noise, the precision of absorbance measurement is theoretically best when the absorbance is near 1.0. So if the peak absorbance is below 1.0, then using the peak wavelength is best, but if the peak absorbance is well above 1.0, you might be better off using another wavelength where the absorbance is closer to 1. Another issue is calibration curve non-linearity, which can result in curve-fitting errors. The non-linearity caused by polychromatic light is minimized if you take readings at either a peak maximum or a minimum, because the absorbance change with wavelength is the smallest at those wavelengths. On the other hand, using the maximum increases the calibration curve non-linearity caused by stray light. Very high absorbances cause two problems: the precision of measurement is poor because the transmitted intensity is so low, and the calibration curve linearity is poor due to stray light. The effect of stray light can be reduced by taking the readings at awavelength where the absorbance is lower or by using a non-linear calibration curve fitting technique. Finally, if spectral interferences are a problem, the best measurement wavelength may be the one that minimizes the relative contribution of spectral interferences (which may or may not be the peak maximum). In any case, don't forget: whatever wavelength you use, you have to use the exact same wavelength for all the standards and samples. See http://terpconnect.umd.edu/~toh/models/BeersLaw.htmlTom O'HaverProfessor Emeritus
What are two reasons why absorbance measurements are taken at lambda max?
to ensure maximum absorbance of light by the solution
What is the specific absorbance of aspirin?
If you have a spectrofotometer ( the thing to mesure the absorbance) then play with the setting and use a maximum. this will lay close to your specific absorbance or take the pharmacopea or a MERCK index
What is the purpose of villi in living cells?
villi are present to increase the surface area of cell for maximum absorbance of nutrients
How to calculate lambda max?
using uv-visible spectrophotometer concentration vs absorbance is plotted and the maximum absorbance of the drug is lambda max of the drug. then after it will decrease. still if needed clarification, refer beer lambert"s law
What is analytical wavelength?
Absorbance maximum
What is maximum wavelength of absorbance of potassium permanganate?
520nm
Why do you use the wavelength with the maximum absorbance in spectroscopy?
Short answer:Using the maximum wavelength gives us the best results. This is because at the peak absorbance, the absobance strength of light will be at the highest and rate of change in absorbance with wavelength will be the smallest. Measurements made at the peak absorbance will have the smallest error.Long answer: It really depends on what is the largest source of error. Taking the readings at the peak maximum is best at low absorbance, because it gives the best signal-to-noise ratio, which improves the precision of measurement. If the dominant source of noise is photon noise, the precision of absorbance measurement is theoretically best when the absorbance is near 1.0. So if the peak absorbance is below 1.0, then using the peak wavelength is best, but if the peak absorbance is well above 1.0, you might be better off using another wavelength where the absorbance is closer to 1. Another issue is calibration curve non-linearity, which can result in curve-fitting errors. The non-linearity caused by polychromatic light is minimized if you take readings at either a peak maximum or a minimum, because the absorbance change with wavelength is the smallest at those wavelengths. On the other hand, using the maximum increases the calibration curve non-linearity caused by stray light. Very high absorbances cause two problems: the precision of measurement is poor because the transmitted intensity is so low, and the calibration curve linearity is poor due to stray light. The effect of stray light can be reduced by taking the readings at awavelength where the absorbance is lower or by using a non-linear calibration curve fitting technique. Finally, if spectral interferences are a problem, the best measurement wavelength may be the one that minimizes the relative contribution of spectral interferences (which may or may not be the peak maximum). In any case, don't forget: whatever wavelength you use, you have to use the exact same wavelength for all the standards and samples. See http://terpconnect.umd.edu/~toh/models/BeersLaw.htmlTom O'HaverProfessor Emeritus
How does the wavelength of maximum absorbance relate to the color of a substance?
The wavelength of maximum absorbence relates to the color, because the only color that is not absorbed will be the color of the item. For example, plants are green because they absorb red and blue light, and reflect green light.
What are two reasons why absorbance measurements are taken at lambda max?
to ensure maximum absorbance of light by the solution
What is the maximum absorbance for beta-carotene?
454 nm
What is the specific absorbance of aspirin?
If you have a spectrofotometer ( the thing to mesure the absorbance) then play with the setting and use a maximum. this will lay close to your specific absorbance or take the pharmacopea or a MERCK index
Why is red light having maximum wavelength?
Because red light has minimum frequency and thus it has maximum wavelength.
What is maximum wavelength in the spectrum?
The wavelength is the spatial period of the wave and it can be measured between any 2 points with the same phase. The maximum wavelength in the spectrum is 502 nm.
Is any wavelength maximum is universal?
No.
What is the purpose of villi in living cells?
villi are present to increase the surface area of cell for maximum absorbance of nutrients
How to calculate lambda max?
using uv-visible spectrophotometer concentration vs absorbance is plotted and the maximum absorbance of the drug is lambda max of the drug. then after it will decrease. still if needed clarification, refer beer lambert"s law
