colorimetry (1 Viewer)

[crammy90]

is it just a device which is like a portable aas?

 

[Azreil]

"A colorimeter or a digital camera with a color filter array can, under certain conditions, be used as an alternative to a spectrophotometer."

Source: http://en.wikipedia.org/wiki/Colorimeter

Colorimeters can also measure things such as the concentration of MoO4 in solution, which when reacted with Ascorbic acid, produces a deep blue colour (deeper = more concentrated).

AAS measures concentrations of metals only (I believe). I'm messaging my mum who works in a chemical lab to make sure of that >>

 

[crammy90]

ok cool
do we need to know about it u rekon
like what u said about it changing the colours of solutions?

 

[Azreil]

I know it because it's the example I use if asked to give a monitoring technique of a specific ion. I think realising that generally, a deeper colour will have a greater concentration of (whatever solution) will be sufficient.

I haven't seen a question about a colorimeter though.

 

[danz90]

I think they also use colorimetry as an extremely accurate quantitative analysis of turbidity.

 

[crammy90]

i just wrote up my summary notes after researching colorimetry
to summarise
WHAT? instrument which quantitatively meansures the amount of light absorbed by a sample
HOW? it consists of:
light source----filter-----sample-----detector
as you notice, the filter is before the sample, not after like in AAS.

• first the filter is set to block out all other wavlengths that the sample is not going to absorb.
• A sample cell of distilled water is put in and performed on. The result recorded by the detector here is the amount of light being shone through the same (as there are no cations in distilled water to absorb any)
• The sample cell of the sample to be measured replaces the distilled water sample and is performed on. There are cations in this sample so some are absorbed
• CALCULATIONS: you do
  • Recording(distilled water) - Recording(sample) = amount absorbed
  • Then as absorbance is proportional to conc yeh...
  • i guess they also beforehand prepare samples of known concentrations in between the distilled water sample and the actual unknown sample to they can produce a calibration curve.

tha sample cell of distilled water is put in place. This has no cations

 

[henry08]

I misread your first post. I thoguht you said " a portable ass" lol.

 

[crammy90]

I misread your first post. I thoguht you said " a portable ass" lol.

lol it wasnt long ago u thought i started a thread about condoms aha