Low but stable Internal standard recovery on ICPMS 7900

Question

Hi
The internal standard recovery on ICPMS 7900 recently falls down right after calibration blank. All the controls and references are OK but the recovery percentage is too low, 20-30%, does anybody had the similar problem? The concentration is as before.
Thank

emretoprak · Accepted Answer

Is it possible that you do not have the same matrix in your rinse and the standards? It seems to me a matrix issue. Otherwise you would have a random pattern or a continuous up/down drift, if there was an issue in your sample introduction. ISTD% recovery will be calculated against the calibration blank, so you might measure the calibration blank multiple times at the beginning, to see if there is an issue in your uptake time settings. Afterwards you can switch between different versions of the calibration blank in the data analysis to see the difference. Keep in mind that you will need to configure only one calibration blank at the end. So, you can define the other cal. blank measurements as rinse or sample.

emretoprak · Answer

Hi Gavin, your sample is way too concentrated for ICP-MS. It is difficult to say before we see the replicates but I would recommend finding a way to measure it with 1:1000 dilution or you can go with UHMI (Ultra High Matrix Introduction) method, if you have it in your software available. 0.5 g in 50 mL = 10000 ppm. It is even for OES way too concentrated.

Low but stable Internal standard recovery on ICPMS 7900

Top Replies