[PeacefulChaos379]

Hi everyone, not sure if this is the correct place for this question.

I'm currently looking into the possibility of using near infrared spectroscopy to detect concentrations of certain substances in a complex solution with multiple components/species. I was wondering what kinds of methods are currently used or being researched for such purposes. The extent of my knowledge on this right now is Beer's law (A=εcl) and a basic understanding of how spectroscopy works, where there is a single solute.

Are there any resources I could read/learn about such things? I'm also interested in the "minimum" required concentration of a species in a solution to be detectable by infrared spectroscopy.

In order to better understand this topic, I've attempted to do a little research in areas that would cover these topics (e.g. NIR spectroscopy used for non-invasive glucose monitoring), but I found that this was a poor starting point for expanding my knowledge base.

[Borek]

Any analytical chemistry book covering instrumental methods should have a chapter on spectroscopic methods. Beware: IR methods are typically used for the determination of the structure of organic molecules, not for quantitative analysis. But as a first approximation Lambert-Beer's law is a way to go.

[marquis]

Start with instrumental companies specializing in NIR. 

The NIR used to be primarily NIRr ( NIR reflectance).  Often, it was used in agricultural applications.  When discussing the process with company chemists, don't be surprised to hear talk about second derivative plots, etc.  And often, they are very guarded about what they will disclose.

Was trying to use NIR for a medical application.  The data looked good.  But we couldn't proceed because the instrument company wouldn't disclose the calculation.  The FDA requires that data for submission.  Oh well.