Basic Training 4th Annual ICP Conference

Key observations to consider for this case: • The background of the high matrix samples has shifted up compared to the low matrix standard of Mn. • The true background for the samples is somewhere between the red line and the black line shown. • The peak is not centered (let’s manually calculate). 0.1 ug/g Mn No internal standard present 312,010 cps to the black background (BG)

Fe Pieces

( 60,370 cps using the red BG (19ppb ) (84,860 cps using the black BG (27ppb)

Fe Powder ( 15,740 cps to the red BG (5ppb ) (40,295cps to the black BG (13ppb)

Acid Blank

Initial Summary of Results

By ICP-OES using a calibration curve w/o an internal standard: • Fe Pieces contains 19-27ppb Mn • Fe Powder contains 5-13ppb Mn With ICP-MS standard additions method: • Fe Pieces contains 36ppb Mn • Fe Powder contains 9ppb Mn (Known interference bias on mass 55 Mn + with 54 FeH + ) Standard additions method by ICP-OES is probably best. Would correct for signal quenching and help resolve the elevated background questions.