Hello!
I performed LA-ICP-MS experiment using NIST 610. I also measured the concentration of different elements on NIST 612 for quality monitoring and control puroposes. I noticed that for all elements of interest, their calculated concentrations in the NIST 612 sample was very close to the accepted standard value, with the exception of Titanium which was way higher than the accepted one. What could be the reason of this?
Thanks
Can you give us a few more details on your instrumental setup to help determine why you are having this issue?
Which isotope of Ti were you measuring? Could it be measuring another isotope of Ca, V or Cr? (Isobaric interference)
Could you be getting polyatomic interference from nitrogen/oxygen/sulfur/ argon/carbon molecules recombining in the plasma? (May and Wiedmeyer 1998 have an extensive list of polyatomics).
Hello Matthew Wheal and thank you for you answer.
I am performing LA-ICP-MS on a slag sample with laser energy of 3.8mJ, repetition rate of 5 Hz and spot size of 38µm. I am measuring 29Si, 44Ca, 48Ti, 51V, 52Cr, 55Mn, 59Co and 60 Ni. I am new to ICP analysis, but it was interesting to see that only 48Ti is being way off the actual data of the other standards that were measured for QC.
Thank you.
Faisal
So, according to my table of isotopes (Pure Appl Chem 1989 vol 63 no7 p991-1002), 48Ti is 73.8% of total TI composition, but there is also an isotope 48Ca which represents 0.187% of total Ca.
Could you be getting some 48Ca in your 48Ti measurement?
It probably won't cost you any extra time or money to measure 47Ti (7.3%) or 49Ti (5.5%), neither of which have isobaric interferences.
Perhaps 46Ti (8.0% of Ti) with 46Ca (only 0.004% of Ca) might be an option too.
I haven't used an LA-ICP-MS, so there may be some other things that other users might know about.
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts