Analysis of Ag, Sb, Sn (ICP-MS Agilent 7900)

Hi everyone. Im using the Agilent 7900 for the analysis of a bunch of analytes in water samples without any problems, except for Ag, Sb and Sn. Im having a problem with the calibration curves of these three analytes because the calibration curves are not linear, it almost seems theat I swaped the points of the calibration between each other. So of course I tried to clean every part, changed all tubings, I have new conuses, every reference material and solution are fresh. Im using macerated plastic bottles for storage of the solutions, adding HNO3 into every solution. Im using He mode, and I chose the following isotopes: Ag 107; Sn 118; Sb 121. The points of the calibration curves for the Ag and Sb are 1; 25; 50; 75; 100 ppb and for the Sn 10; 250; 500; 750; 1000 ppb. And I measure them together with the following analytes: Li, Be, B, V, Se, Sr, Mo, Ba.  So I was wondering, if anyone has a similar problem. Or someone has an idea what should I try. Thank you very much.

Parents
  • Hi Metallica,

    This is a typical problem of the chemical stability of the elements. Ag, Sb, Sn aren't good stable in low concentration HNO3. However if there is some HCl present then the stability is far more better. I don't know the HNO3 concentration but try to repeat the test when adding extra (1%?) HCl to all the blanks and standards. probably it goes much more better.

Reply
  • Hi Metallica,

    This is a typical problem of the chemical stability of the elements. Ag, Sb, Sn aren't good stable in low concentration HNO3. However if there is some HCl present then the stability is far more better. I don't know the HNO3 concentration but try to repeat the test when adding extra (1%?) HCl to all the blanks and standards. probably it goes much more better.

Children
Was this helpful?