ICP-MS and standard addition
Posted: Sat Apr 20, 2024 6:18 pm
I would like to improve sensitivity of copper detection in our growth media using the Agilent 8900 ICP-MS. We aim to reduce the limit of quantification from the current 0.1 ng/ml to a lower range, ideally 0.05 or even 0.02 ng/ml.
This is challenging due to the high matrix nature of the media, which includes HEPES and salts, and may contain trace amounts of copper contamination.
One idea is using the standard addition method to address this. We would add known amounts of copper to the growth media, to a final concentration of 10, 20, 40, and 100 ng/ml. We then create a calibration curve that plots the response against the copper concentration. This curve allows us to estimate the response at lower concentrations, specifically targeting 0.05 ng/ml.
But I think there are potential limitations to consider. The relative standard deviation (% RSD) of the counts per second and instrument drift could affect the accuracy of our measurements. Is this a reasonable approach?
There must be a limit to the effectiveness of standard addition at very low concentrations.
This is challenging due to the high matrix nature of the media, which includes HEPES and salts, and may contain trace amounts of copper contamination.
One idea is using the standard addition method to address this. We would add known amounts of copper to the growth media, to a final concentration of 10, 20, 40, and 100 ng/ml. We then create a calibration curve that plots the response against the copper concentration. This curve allows us to estimate the response at lower concentrations, specifically targeting 0.05 ng/ml.
But I think there are potential limitations to consider. The relative standard deviation (% RSD) of the counts per second and instrument drift could affect the accuracy of our measurements. Is this a reasonable approach?
There must be a limit to the effectiveness of standard addition at very low concentrations.