Olena Pareniuk, could you expand the causes of contaminants? Because you can not remove the sample?  

Rodolfo Andrés Martiarena, it is radioactivity. I am just not allowed to take samples out of the exclusion zone.

Dear Olena,

How many samples are you going to analyze? That's an important point. If there are only 10 or 20 - you should use some cheap methods, which provide not very accurate results. However, if you take part in a huge research project - you can buy all the necessary equipment and use it in your ongoing and future studies.

Dear Tymur,

Thank you for your comment, but the point of my question is that it is impossible to use all the equipement, avalable in laboratories - and it does not depent on the size of the project I am involved in or the amount of the samples.

So my option are express metods, which provide accurate results. I would appresuate you advice about the exact trademarks or suppliers.

Thank you! 

You might look into USArmy surplus for field portable SEM with microprobe. These were supplied in Humvees during Iraq war for forensic work, and I am aware that at least one of my colleagues was able to atain one for his commercial lab. Though you might not be able to trek with one, they were designed to be portable via the jeep. Ion microprobe can extend to C and N under some equipment conditions, but I am not sure if those instruments have that capability.  

Otherwise, I would fall back to portable colorimetric photometers and wet chemistry kits like Hach produces. Fe and the halogens will be amenable, and COD and Kjeldahl N  digestion kits are also part of their gear. It could at least help you grid the extant of the problem/ solutions you need to establish. 

Good luck!

Thank you, Sid. I was also thinking about colorimetry, but had a small hope, that will be able to find something more presise...

Olena, the best choice would be checkers from Hanna. You can find them here http://shop.hannainst.com/products-by-category/checkers/show/36.html?id=045001 They are very cheap (about 50 USD) and can be used for a long period of time. By the way, you can use one checker for multiple parameters  - you just need to know the proper wavelength. 

Tymur, that is marvelous! It is exactly what I wanted!

Thank you so much! :)

Do not forget the very basic soil description in the field using the guidelines from FAO 2006. Free download at

ftp://ftp.fao.org/agl/agll/docs/guidel_soil_descr.pdf