[bobs]

I do not have standard for analyte of interest. How can i quantify it in my extract.

[Arkcon]

That is going to be a tough one.  Technically, you can't.  At least, some regulatory bodies wouldn't accept data under those circumstances.  You may be able to get useful work from an analogue, or a reasonably similar molecule.  Or you may be able to find a reference, for a very common molecule, that will identify constants you can use to calculate your unknown based on instrument response.

[wpenrose]

Sometimes it's possible, but you're going to have to tell us what analytes you're after, and what the matrix is, and what method you're using. For example, a good coulometric analysis equates (time x current passed) exactly to moles.

DB