Stanadard Solubility Issue

[HARS]

Standard Solubility Issue:

I am having the solubility issue with the standard preparation. Since last 6 months Standard is being prepared in same way and i never had any issue. Out of the blue, since Monday standard is not dissolving in diluent. I tried different experiments like new diluent preparation, new standard bottle, and different concentrations etc., but nothing giving the positive results.

Diluent: 0.1%TFA

Any suggestions please?

Thanks

[DR]

Make sure you have the correct standard...
Seems obvious, but it is a mistake I've made (so many little vials, all look the same).
Also consider the possibility that someone else made that mistake when filling the new vial you may be working with.

[HARS]

Thank you Dr.

I have been using the same bottle at least for the last two months. Today i opend new bottle and prepared again.

[danko]

Maybe “new bottle” does not necessarily mean different stuff. If it comes from the same batch, you still might have the same issue as DR pointed out above.

Best Regards