Chemical Stability and Compatibility - Mixing metal standards and the correct matrix choice
Responses | |
---|---|
admin
Total posts: 529
|
These are excellent questions. As a general rule, as concentrations decrease more elements can be combined to form stable solutions. The elements you list (V, Sr, Cr, Cu, Mn, Ti, Na, Zn, Pb, Mg, K, Al, Fe, S, Ca, As) are all stable when combined at concentrations of 100 ppm or less in matrices of 2-10% HNO3 / trace HF (where trace HF is ~0.1% by volume). Therefore, combining IV-ICPMS-71A with Ti stabilized in HNO3/HF should present no issues, as long as the Ti is roughly equal in concentration to the other elements you list. We can quote a custom standard that should meet your exact needs, but the approach you mention is likely to be more cost effective. As for the final matrix, the critical consideration is that your standards and samples should have the same matrix. The IV-ICPMS-71A product can be diluted in any concentration of HNO3 between 1-10% with no concerns. As for adding Br and Cl, these elements could be added to a custom standard in an acidic matrix for ICP-MS analysis. If you choose to add these elements yourself, we do recommend using ammonia forms (i.e., NH4Br and NH4Cl) to avoid creating unintended interferences that may arise when sourcing Br and Cl from more typical salts (e.g., KBr and KCl). |