The invention relates to a sorbent collector material based on polyorganosiloxane for the microextraction of substances to be analysed, the collector material having an open-cell foam structure, and to a collector and a liner which include this collector material. A herbicidal composition comprising flazasulfuron or its salt, and at least one herbicidal compound selected from the group consisting of imazapic, hexazinone, mesotrione and their salts, and a method for controlling undesired plants using it. Truncated polynucleotide sequences can be used to produce truncated toxins or for the production of fusion genes and proteins. Speed allows larger images to be made. The materials, geomentry and electrical parameters of the stent with passive resonant circuit are chosen and arranged so that incident electromagnetic radiation induces currents in the passive resonant circuit that optimize imageability during MR scanning.