Page 1 of 1

Filtration step in sample preparation of pesticide analysis

Posted: Fri Feb 16, 2018 8:32 pm
by Dr.Malik
Hi all,
Is it important to apply filtration of the aliquot after clean-up step in sample preparation of food samples before injection in LC MSMS or GC MSMS.
And if please can anyone provide me any paper or reference for that.

Re: Filtration step in sample preparation of pesticide analysis

Posted: Sat Feb 17, 2018 5:46 pm
by James_Ball
Filtration should only be needed if there are particles to worry about, and that will matter more in LCMSMS than GCMSMS since those would plug the column. I don't have any reference but it is good practice to make sure you have particles less than 0.22um when running LC.

Re: Filtration step in sample preparation of pesticide analysis

Posted: Mon Feb 19, 2018 2:22 pm
by Rndirk
Agree with James.

In a typical Quechers sample preparation, following the salting out step, we perform the clean up for LC and GCMSMS:

LC-MSMS

- Evaporate under nitrogen until dry
- Redissolve in starting mobile phase
- Filtrate using push-through filter vial 0.2µm

GC-MSMS

- Take 1.5mL of acetonitrile phase in dSPE tube
- Shake 2min
- Centrifuge
- Transfer part of supernatant to GC vial

As you see, no filtration for GC. But there is centrifugation and no solvent switch, so much less risk of solids remaining.