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physiks2011
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What does it mean if one found negative absorption in uv-vis absorption graph?
A negative absorption peak in FTIR (Fourier Transform Infrared) spectroscopy refers to a dip in the absorbance spectrum, where the intensity of the infrared radiation passing through a sample decreases. This indicates that the sample is absorbing less infrared light at that particular wavelength.
A negative absorption peak in FTIR can be caused by a variety of factors, such as the presence of interfering substances, changes in the sample's molecular structure, or errors in sample preparation. It can also be a result of instrument noise or baseline fluctuations.
Yes, a negative absorption peak can be used as a characteristic feature for identification of a sample. It can provide information about the functional groups present in the sample and their molecular environment. However, it should be considered alongside other peaks and factors to accurately identify a sample.
If a negative absorption peak is due to instrument noise or baseline fluctuations, it can be corrected by taking a baseline measurement and subtracting it from the sample measurement. However, if it is caused by interference or other sample-related factors, it may require further analysis and adjustments in sample preparation.
No, negative absorption peaks are not always undesirable in FTIR analysis. In some cases, they can provide valuable information about the sample's molecular structure and functional groups. However, if they are caused by errors or interference, they may affect the accuracy of the analysis and should be corrected or investigated further.