LOQ & LOD - What about in between?

Hi All,

Say for example I have an active with a LOQ of 0.10ppm and LOD of 0.05ppm.

My limit only requires me to clean to 0.09ppm.

Is there a technique so that I can claim i am most defintely below my LOQ without have to get a ‘none detected’ i.e. below my LOD?

Much appreciated FIn

Dear Mr. Fin
When your instrument’s LOQ (for a specific active) is 0.10 ppm and your target is 0.09 ppm, your instrument is not suitable!
Go for more sensitive instruments or increase the swab / rinse area or decrease the dilutions so as to get a (swab /rinse) sample with higher concentration.


Mr. Fin,

Practically speaking changing your procedure of swabbing is quite difficult as you need to see the recovery aspects from QC perspective like changing amount of solvent, etc. Also try to check your obtained value is w.r.t matrix or only with that product. If it is w.r.t matrix then you may have a chance to get more value if you check MACO for that product with all products. Fix this value and then try.
If you provide more data then i may suggest some other option.