Determination of a chemical compound in a non-homogeneous sample I want to know if it is possible to determine a chemical compound in a non-homogeneous sample. I am asking this because we are aiming to create a device that will detect histamine level in fish without homogenizing the samples. In all the journals we've read (which are a lot), fish samples are homogenized (blended + chemically-treated) before histamine is determined.

I am a computer engineering student with basic knowledge on biochemistry. I'm researching on this because this is our thesis topic (which our adviser has forced recommended to us).

Any help/recommendation regarding this is appreciated. Thank you!
If you analyze non-homogeneous samples, the results can't be interpreted as being representative of the whole organism (or population). So, for example, if histamine is unevenly distributed within the body of a fish, your results would vary widely depending on what part of the fish you analyzed.