[jubba]

i understand how ir-spectrscopy can be used to identify organic compounds.

But how is it used to work out the composition of other compounds esp. in pigments.

I know some metals(such as copper) in solution absorb infrared radiation but what about compounds which are not soluble in water (which is is most pigments)

[Albert]

Honestly, I've always thought you use UV spectroscopy with pigments. 

[green-goblin]

I thought you didn't dissolve your IR samples in water as water dissolves your IR plates. Is it DCM thats used to dissolved samples for IR? Can inorganic pigments be dissolved in this?

But yeah seeing as pigments are coloured i thought you would use UV/vis spec

[jubba]

Well the question was describe the use of uv and infrared light in the analysis of pigments such as zinc oxide as zinc oxide and those containing copper

I know zinc oxide goes from yellow to white in infra red. but thats about all i know. 

[ATMyller]

You can mix the solid compound with IR-transparent material eg. KBr and press it into a tablet. With this method you'll need to measure the background spectrum using pure KBr.
Or you could use reflection IR-methods like ATR
Zinc oxide can't be measured well with UV/VIS because it reflects UV radiation.

[jubba]

thanks guys

[jubba]

is this right:

ATR is a non-destructive but qualitative method for analysis of pigments