SPE Recovery calculation

[Edde]

I have a 1mL 200 ug/mL aqueous standard for MAX extraction, then elute with 2mL elution solution. For injection, the eluate is injected directly without evaporation and reconstitution. Hence the final conc. becomes 100 ug/mL.
To compare extraction recovery, should I spike standard to extracted blank matrix at 100 ug/mL or 200 ug/mL final conc.?

Please kindly comment.
Thanks.

[richiekichi]

Hello there,

You'll be wanting to have your spiked samples within the range of your matrix matched calibration standards. For example, if you've spiked at 0.1 ppm then you might run standards from 0.5 ppm to 0.01 ppm or something.

"I have a 1mL 200 ug/mL aqueous standard for MAX extraction, then elute with 2mL elution solution." <----- This is your spiked sample.

"To compare extraction recovery, should I spike standard to extracted blank matrix at 100 ug/mL or 200 ug/mL final conc.?" <----- This is your calibration standard.

Something else to consider, although you are eluting with 2 mL, is your final volume 2 mL?

All the best.

[Edde]

although you are eluting with 2 mL, is your final volume 2 mL?

yes, since I apply pressure to the SPE cartridge, all elution solvent should be forced out.

Thanks.