[yy]

Hi - I am setting up an experimental design to determine calcium content in water by using atomic emission spectrometry.

I used flame photometry just for once, when I determined the sodium content in beers. In that session, we used KCl & NaCl to create our standards.

In setting up an external standard for Ca in water, what compounds are best to be used? I know CaOH is not a good one as it precipitates out.
I am considering CaCl2 - but wondered as Calcium compounds seem to precipitate out in most cases. 
Are there any Ca compounds that would not precipitate?

Any advice is appreciated. Thank you.

[ARGOS++]

Dear yoshimi;

40.0 g / 100ml:    http://en.wikipedia.org/wiki/Calcium_acetate 
16.6 g / 100ml:    http://en.wikipedia.org/wiki/Calcium_bicarbonate

Good Luck!
                    ARGOS⁺⁺

[yy]

Many thank you

[ARGOS++]

Dear yoshimi;

You 're welcome!   ─   Soon again.

Good Luck!
                    ARGOS⁺⁺

[yy]

I am interested in your preferences:

If you are to examine the content of Calcium in water samples, which of the following technique would you prefer to use? and Why?   Calcium has 423nm (wavelength).

1. Atomic Absorption
2. Atomic Emission
3. UV-Vis Spectrometor
4. Fluorimetry

[Fleaker]

I think atomic absorption would work well, providing you have the hollow cathode lamp for Ca.

I can't see what you could make of calcium that would fluoresce or quench fluorescence. UV-vis wouldn't be too useful either unless one can make a coloured complex (unfortunately, I have no idea if an analytical one exists).

Atomic emission would work, but it would not be cheap.


If you're trying to do it on the cheap, what's wrong with gravimmetric methods?