I am trying an adsorption experiment in which the spectrophotometric readings are taken for albumin and bilirubin dissolved in PBS .I am getting the readings starting from 1.678 to 2.559 like that.Are the readings correct or should i increase the dilution factor?
IF you are speaking of IR-measurements - the range of intensities which provides correct and reproducible results is:
a) for transmissional mode 20-80%
b) for absorbance - below 0.8
If the numbers are higher - it wll lead to distortion of spectra: the peaks will be "cut off" and the bands will broaden.
Thus no quantitative measurements under such a conditions will be possible - this means that you should dilute your solutions in order to fulfil the measurements conditions.
Regards, Leonid
If you are asking about UV-vis, the readings of A >1.8 are not reliable. Try to keep A in the range 0.1-1.6 to minimize the errors associated with your instrument. In addition, check the spectrum of your (cell +solvent) using empty cell holder as a blank. If the absorbance is high, >1, this could create problems for your instrument,
Hello Betty,
The accuracy of Absorbance readings greater than 1 ABS, very much depends on the stray light of your UV/Visible spectrophotometer.
The lower the stray light, such as less than 0.02%, the more accurate the higher Absorbance readings.
Kind regards,
Ade Kujore
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Absorbance values should not exceed 1.0, in this case, reproducible results are obtained. so that if the measure of absorbance higher values it is necessary to dilute the solution.
Low transmitted light intensity will produce inaccurate and imprecise absorption values. Since A = log Io/It (Io = incident beam intensity; It = transmitted beam intensity), examine the following which explain as well Yurii and Leposava:
Log 100/10 = log 10 = 1.0000
Log 100/1 = log 100 = 2.0000
Log 100/0.1 = log 1000 = 3.000