System comprising at least one collection device for collecting nano particles conveyed in a fluid (F) in order to determine the exposure of the collection device to nano particles (N), wherein said collection device comprises parts of a fluid duct having a fluid inlet and a fluid outlet , and a fluid propelling element propelling said fluid (F) through the fluid duct , wherein the fluid outlet is part of said collection device ; wherein the collection device comprises a chamber and wherein the system comprises further a collection cartridge that is separate from the collection device but is insertable into the chamber of the collection device , wherein the fluid inlet , parts of the fluid duct and at least one collection element are part of said collection cartridge , wherein the at least one collection element is arranged in said fluid duct for the collection of nano particles (N) conveyed in said fluid (F), wherein the collection element comprises a collection surface and an enhancement structure which enhancement structure is arranged in connection with said collection surface , wherein said nano particles (N) are deposited in the region of said collection surface and said enhancement structure and wherein said collection surface with the enhancement structure enhances the spectral properties of said nano particles (N) for enabling a facile analysis of the amount of collected nano particles (N); wherein via a fluid duct interface , which is arranged within said chamber , the parts of the fluid duct of the collection cartridge are connected to the parts of the fluid duct of the collection device ; and wherein the system comprises further a spectrometer , which is suitable for Raman spectroscopy, wherein the collection device is separate from the spectrometer and is insertable into the spectrometer in order to analyze the amount of collected nano particles, wherein the collection cartridge is removeable from the chamber of the collection device within the spectrometer before the analysis of the amount of collected nano particles. wherein said collection device comprises parts of a fluid duct having a fluid inlet and a fluid outlet , and a fluid propelling element propelling said fluid (F) through the fluid duct , wherein the fluid outlet is part of said collection device ; wherein the collection device comprises a chamber and wherein the system comprises further a collection cartridge that is separate from the collection device but is insertable into the chamber of the collection device , wherein the fluid inlet , parts of the fluid duct and at least one collection element are part of said collection cartridge , wherein the at least one collection element is arranged in said fluid duct for the collection of nano particles (N) conveyed in said fluid (F), wherein the collection element comprises a collection surface and an enhancement structure which enhancement structure is arranged in connection with said collection surface , wherein said nano particles (N) are deposited in the region of said collection surface and said enhancement structure and wherein said collection surface with the enhancement structure enhances the spectral properties of said nano particles (N) for enabling a facile analysis of the amount of collected nano particles (N); wherein via a fluid duct interface , which is arranged within said chamber , the parts of the fluid duct of the collection cartridge are connected to the parts of the fluid duct of the collection device ; and wherein the system comprises further a spectrometer , which is suitable for Raman spectroscopy, wherein the collection device is separate from the spectrometer and is insertable into the spectrometer in order to analyze the amount of collected nano particles, wherein the collection cartridge is removeable from the chamber of the collection device within the spectrometer before the analysis of the amount of collected nano particles. <EOS>