[Jayo]

Hi all,

I am midway through an assignment and wondered if anyone could help. The first question is the basic principles of ATR, which I have done. The second part to that is how is it used for 1) measuring the IR spectra of aqueous solutions, and 2) in industrial process control?

The other question I was struggling on  was finding info on effects leading to deviations from the Beer Lambert law. These effects are divided up into: those caused by IR instrumentation; those caused by sample prep and those caused by chemical and physical effects on the sample molecules.

If ayone can help me, or lead me in the right direction, it would be greatly appreciated    

[marquis]

I can help with a little of it.

You may want to look up MIR (multiple internal reflections).  It's another name for ATR.

The solid atr is often used for coatings.  You can identify the material on the surface with minimum interference from the base material. 

There is also a microscope FTIR/ATR accessory for very small particles.  It was usually used when the regular microscope IR gave no information.

The liquid accessory saved preparation time.  Its like a small depression in a ATR plate.  Much easier than trying to put a liquid between two salt plates.  With salt plates, you may have to play with spacers to get the thickness right.

The current ultimate ATR is the Diamond cell.  Never got to play with that.  Always stuck with KRS-5 instead.