Why do you use the wavelength with the maximum absorbance in spectroscop?

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 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 absorbance not measured directly?

Simply because we cannot measure light absorbed. We are, however, able to measure light transmitted through the use of a spectrophotometer. The device works by shining light of a specific wavelength on a substance and measuring the amount of light that gets through. This "transmittance" has a negative logarithmic relationship to absorbance.

How do you find the concentration of potato cells immersed in salt solutions?

You would have to use a spectrophotometer to measure the absorbance of your unknown solution. But first, you need to make several solutions with known concentrations. Measure the absorbance of the known concentrations and plot them on an X and Y axis where X equals concentration and Y equals absorbance. Do a best-fit line for your data. Measure the absorbance of your unknown solution. Find this value on your Y-axis and find out where this value intersects with your line of best fit. The X value at the intersection is your concentration of potato cells. By the way, make sure you use the same wavelength throughout the experiment.

Function of the spectrophotometer?

The spectrophotometer is an instrument that measures the amount of light of a specified wavelength which passes through a medium. This instrument operates by passing a beam of light through a sample and measuring the intensity of light reaching a detector.

What is blank in spectrophotometer?

A blank is used in order to cancel out or zero the absorbance of all the other components in the sample except the component whose absorbance is to be measured. For example, if you want to measure the absorbance of a solute in water, you will use only water as a blank and the spectrophotometer will subtract the absorbance of water from the spectrum when you measure the absorbance of your solute in water.

What is the formula that use to calculate the concentration of glucose in blood by the principle of Beer-Lambert law and application of glucose oxidase?

patients absorbance/absorbance of the standard*concentration of the standard gives you the glucose concentration of the patients sample

What is λmax?

A more powerful version of Wi-Fi that can provide wireless internet access over wider geographic location such as a city.

What happens if you use a 0.5cm cuvette in a 1cm cuvette spectrophotometer?

The absorption of sample at maximum wavelength will be reduced by1/2 . Vijay Bhoir (Flamingo pharmaceuticals Ltd.Rabale Navi Mumbai ).

Using planck's law determine the wavelength of maximum emission intensity for blackbody with a temperature of 6000K?

Use the formula Lamdamax*T = b Where b is Wein's constant, 2.898 x 10^-3 m K you get Lamdamax = 4.97 X 10^-7 m this wavelength represents UV light.

How do you determine wavelength of source in diffraction grating?

In diffraction grating we use the expression N m L = sin @ Here N is the number of line per meter length in the gartin. m the order (1,2,3) L- lambda which stands for the wavelength of monochromatic light used to perform experiment And @ is the angle of diffraction for which we get maximum

Why do you use the wavelength with the maximum absorbance in spectroscop?

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