FTIR - Lab Report Example

Download file to see previous pages Different bonds in the molecule of these compounds give respective frequencies which are referred to as the wavenumber (Skoog 2007). As the technique developed, it is also now used for quantitative determinations. This experiment aims to provide knowledge in the use of FTIR in qualitative and quantitative applications. Quantitative determination of the xylene isomers is done through linear regression of the peak responses at the respective bands of the xylene isomers.
In the experiment, a Perkin Elmer Spectrum One FT-IR Spectrometer was used. Qualitative analysis was done on the first part, and a quantitative test was conducted for the second part where the concentration of an unknown was determined using the known concentrations of m-xylene and p-xylene standards.
Qualitative Determination. For the qualitative test, five different materials were scanned; namely polystyrene, polyethylene, polyacetate, cyclohexane and acetone. A background spectrum was first done on the FTIR spectrometer with range from 4000 – 500 cm-1, then the polystyrene was scanned once, then four scans, then sixteen scans. The effect of the number of scans was determined from this step. Five scans each of polyethylene and polyacetate films were done.
The parameter was then changed to 4000 – 450 cm-1, then a NaCl liquid cell was placed in the steel frame. Background measurement was again conducted then the cell was filled with cyclohexane. The spectrum of cyclohexane was measured five times. The cell was then cleaned by pushing the liquid out using a syringe and collecting it on a paper towel. The cell was then rinsed with acetone and dried until there was no more detectable contaminant in the spectra. Acetone was then placed in the cell, and its spectra measured five times.
Quantitative Determination. Solutions of m-xylene and p-xylene were prepared using cyclohexane as diluent at concentration levels ranging from 0 – ...Download file to see next pagesRead More