Chemical Stability and Compatibility

Our lab just recently transitioned from using AAS to ICP-OES for metal analysis. In the industry that I am in , we focus in quantifying the concentrations of the following metals - As, Al, Ca, Cs, Fe, K, Li, Mg, Mn, Na, Rb. I am planning to prepare, or have Inorganic Ventures custom prepare, a calibration standard for low level ICP-OES analysis containing all of the said elements. I am wondering if all these elements are compatible, how should the preparation be done and if possible the problems that may arise in having this set of metals in one standard.

Mercury (Hg) is an element always avoided in multi-element solutions for stability purposes. I try to understand why…….can you please shed some light on the problem?

I have a question about calibration standards and calibration curves. We do a linear calibration with a blank offset. Most of the elements we test will be at a percent level. These elements usually include Fe, Mn, Zn, Cu, and Na, while we need lower concentration analyses on elements such as Cd, Pb, As, Se. Are there any precautions to making multi element standards? Should we not have elements mixed with other elements?

Hi, I have a problem with Au stability in ICP-MS measurements. I use 10% HCl. I get good calibration curves for other pgm's except for Au which increases with an increase in standards. How can I overcome this? What's the best argon flow rate I could use? What is the best container for storage and rinsing solution?

Is it possible to manufacture very low Hg standards, in the concentration range of several parts-per-trillion (ppt) to several parts-per-billion (ppb)?

We'll be audited in the next week, and we have a doubt about metal solutions. In the Certificate of Analysis there are instructions to keep the material at 20º +/- 4ºC, so I would like to know if you have a study that demonstrated the increase of the concentration in the analyte with the variance of the temperature and the time.

My company recently purchased some pH and Conductivity standards from IV, and I would like to pour an aliquot (50ml) of each type into a sterile bottle and transport to another facility for additional measurements. Do you think the aliquots will be stable enough for up to a week if used only once?

I am looking for a 64-element blend composed of S, Cl, Br, I, Al, Fe, Ca, Mg, Na, K, Si, Mn, P, Mg, Li, Be, B, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Ag, Au, Cd, Hg, Sn, Sb, Cs, Ba, Bi, Th, U, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Tl, Pb. We need to prepare calibration standards diluted from this blend for low-level and medium-level IC-ICP-MS analysis. We will appreciate any information about the compatibility and best ways of preparation of such a blend. Which certified standard solutions you would recommend as the stock solutions?

How could you prolong the date of expiration for CRM? Is this a special storage condition (for example with vacuum and/or low temperatures)? What would be the longest fixed period of time for a CRM expiration period?

I have a weird question for you regarding the stock standards we bought from you guys for the ICP-MS. They are multi-component and CCS-1, CCS-2 etc. The old ones are expired but I was using them to make something like a "check standard". The check standard I made last week and ran it today and the Ag was quite high! Like about 140% of what should be -- BUT all the other analytes were in range. (This was again made with expired standards.) The standards we mix come in 5 bottles and are multi-elemental. So the bottle with Ag also has other analytes in it. But all the other ones in that bottle were in range. I made a new check thing with the new ones and of course that one has no issues. I am just trying to determine if Ag really went "bad" after expiration or if I was actually having some instrument problems with Ag, or if maybe I didn't invert that standard bottle before taking an aliquot and got a lot more Ag since it wasn't evenly mixed. Any ideas from you on this one??