SM 2540 Solids - Crucible materials

[markf]

Hey guys,

This isn't really a student project, but I was unsure where to post this since this isn't chromatography related.
Mods - If there is a better place please move it.

Simplest gravimetric methods there are, total solids/dissolved solids in wastewater.

Our lab techs absolutely hate the porcelain crucibles for this analysis. Our lab performs analysis on all types of wastewater. High organic, low organic, acid and alkali wastewater, you name it.

The method specifies that we can use crucibles/dishes made out of:

1. Porcelain
2. Platinum
3. High silica glass
4. Other material shown to be resistant to the sample matrix and weight stable at the required temperatures (105C for total solids, 180C for dissolved solids)

I thought of trying to use PTFE crucibles.
Of course the method would need to be revalidated.

Any reasons that you would think it won't work?
I know that PTFE melting point is 327 and the manufacturer states that the crucibles are compatible with heating to 280C.

Any thoughts?

[Consumer Products Guy]

We would simply use tared glass beakers for stuff like this, leave in 105C oven overnight.