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- Joined: Fri Feb 10, 2012 7:39 pm
I'm familiar with LOD and LOQ using both gas and liquid chromatography. So what about LOD and LOQ using visible spectroscopy, reading absorbance in cuvettes at about 400nm?
Would one still use the 3X and 10X blank or noise as criteria? Company wants to make a claim that competitor has no "material" in their formulation, but what if competitor adds "fairy dust" amount to a large batch, never could be positively determined. I couldn't testify that there's "none".
So this is just another go-around of how to define "none". My guess is that we'll end up settling for something like this: if present, present below xxx limit, determined from low-level spikes. So would that limit still be 3X the blank/noise for this?
Would one still use the 3X and 10X blank or noise as criteria? Company wants to make a claim that competitor has no "material" in their formulation, but what if competitor adds "fairy dust" amount to a large batch, never could be positively determined. I couldn't testify that there's "none".
So this is just another go-around of how to define "none". My guess is that we'll end up settling for something like this: if present, present below xxx limit, determined from low-level spikes. So would that limit still be 3X the blank/noise for this?
