High RSD

Hi,

i would help, if you could make more detailed statements about you RSDs.

Is it possible, the always the first replicate is to low (which could be an uptake issue)?

Or is the first always to high (contamination from rinse solution e.g.)

Are your sample counts quite low? 

What is your stabilization time for the Helium Mode?

Have you tried another Gas Mode (56 is highly interferred by ArO). Hydrogen should give better results in lower levels of Iron.

Best Regars

Chris

Hi,

There is not a patron, sometimes the first replica has the highest value, sometimes is the middle, and sometimes is the final.

When I check the CPS file the RSDs are always bellow 5% and the CPS use to be higher than 20,000, the problem with the RSDs comes when I check the concentration (ug/mL).

The stabilization time for the Helium Mode is setting in 10 seconds.

I only have tried No gas and Helium mode.

These are some settings that I am using:

Plasma robustness: Low matrix

Preset method: EPA 6020

Acq Mode: Spectrum

Q2 Peak Pattern: 3 points

Sweeps/Replicate: 10

P/A factor adjustment: On

Resolution: Narrow Peak

Scan Type: MS/MS

Thank you for your help!

Kindly,

Catalina A.

Hi,

There is not a patron, sometimes the first replica has the highest value, sometimes is the middle, and sometimes is the final.

When I check the CPS file the RSDs are always bellow 5% and the CPS use to be higher than 20,000, the problem with the RSDs comes when I check the concentration (ug/mL).

The stabilization time for the Helium Mode is setting in 10 seconds.

I only have tried No gas and Helium mode.

These are some settings that I am using:

Plasma robustness: Low matrix

Preset method: EPA 6020

Acq Mode: Spectrum

Q2 Peak Pattern: 3 points

Sweeps/Replicate: 10

P/A factor adjustment: On

Resolution: Narrow Peak

Scan Type: MS/MS

Thank you for your help!

Kindly,

Catalina A.