College Papers

“Infrared” (FTIR) approach is used instead. During sample

“Infrared” is the electro-magnetic radiation region between
0.7µm to 1000µm (Doyle), for chemical
analysis, between 2.5 µm and 25 µm will receive the best results. mid-IR region
is where the most functional groups organic molecules’ frequencies lie, so quantitative
calibration can be done very straightforwardly and it is robust, spurious
artifacts effects will less likely to arise.

Figure 1:
Electromagnetic Spectrum

The nature of black body radiation has led to the radiation source
power available in the mid IR is a lot lower, mid-IR detectors have a lower
sensitivity when operating in room temperature compare to near-IR counterparts.
These two factors are the main reasons why less sensitive dispersive approach is
not used in the near-IR, and Fourier transform infrared (FTIR) approach is used
instead. During sample interfacing, absorptions in the mid-IR relate to the
fundamental molecular vibrations are orders of magnitude stronger than the near
IR overtones, mid-IR will not be able to use simple transmission cells as how
near-IR liquid analysis is carried out.

In Situ FTIR is the Fourier Transform Infrared Spectroscopy,
it has been growing in popularity since its introduction, it is becoming
commonly used in pharmaceutical industry to determine the chemistry in a
chemical. Whenever there is a new chemical entity that needs to enter the
commercial production, the chemical process and the chemistry behind it must be
thoroughly understand in order to have a safe, robust and reliable production
to prevent any consequential reaction occur to human body. The ReactIR in situ
Fourier Transform Infrared answer all the questions in a chemical reaction, it
gives the time it starts, the time it stops, the expected mechanism for the
reaction and its kinetics.

ReactIR in situ Fourier Transform Infrared (FTIR)
Spectroscopy provide real time monitoring of all the key reaction species, it
also shows the changes in the reaction throughout the progression, the ReactIR
Attenuated Total Reflection (ATR) provide the specific information from the reaction
initiation, conversion, intermediates and endpoint, this will allow a much
better understanding of the mechanism in the reaction compare to the old

FTIR Spectroscopy is carried out in situ. In tradition
method, in order to find out the chemical reaction mechanism, kinetics,
conversion etc, chemicals have to be taken out from the reaction and undergoes
varies analytical techniques, these chemical could be very toxic, high
temperature or high pressure, which means it is not always easy to undertake
these analytical techniques, this shows the significances of FTIR Spectroscopy
carried out in situ,  the probe is
inserted directly into the reaction mixture, so reaction sample will not change
during sampling, and it is much more safe to carry the reaction. (MettlerToledoAC)