Abstract: The invention relates to an adsorbent agent with special advantages to heavy metals, proteins, etc. and is based upon a ligand with an atom sequence (A): N--C--C.sub.n --N, wherein n is 1 or 2, and one terminal, a ring atom N in a heteroaromatic ring system, together with a proximal ring atom C forms a first terminal. The second terminal --C.sub.n --N-- can be an integral part of a heteroaromatic ring system with one or more heteroatoms and through a crosslinking bridge D is attached to P. The first terminal N--C-- can be included in a pyridine or imidazole core. The polymer P is organic and hydrophilic such as polysaccharide, polyvinylalcohol, polyacrylamide, polyacrylester, polyethyleneimide or derivatives thereof, and can also be immobilized by crosslinking, binding or adsorption or inclusion in an inorganic bearer.

Abstract: An adsorbent that comprises a solid phase for the isolation and immobilization of proteins by adsorption from a liquid phase is characterized in that it consists of a hydrophilic polymer network with covalently bound ligands of the formula--Y--X--R,in which R is an aliphatic substituent containing at least one nitrile group or a substituent having a heterocyclic ring system with at least one nitrogen atom in the ring and with one or more side groups consisting of or including --CN (nitrile group), whereX is NQ, S, or O, Q being H(CH.sub.2).sub.n, where n=0, 1, 2 or 3, andY is a side chain which joins R-X with the polymer network.The polymer preferably consists of agar or agarose in particle form having a particle size of <1 mm. Y can be --CH.sub.2 --CH.sub.2 SO.sub.2 --CH.sub.2 --CH.sub.2 -- and R can be ##STR1## The adsorbent can be used to isolate biopolymers and, inter alia, has been found highly effective in isolating proteins.

Abstract: Metal ion adsorbent that is formed by an organic polymer having a hydrophilic character through a content of an average of at least 0.5 substituents per monomer unit of any of the following types: OH, O, CO, NH.sub.2, NH or N, so that the concentration of these groups is at least 25 mol-percent. The polymer in a non-aqueous state contains at least 10 .mu.mol of metal binding groups per gram of adsorbent. The metal binding group has 5 coordinating ligand atoms, two of which are nitrogen atoms and three of which are carboxylic acid groups.

Abstract: A process comprising contacting particles of water insoluble polymers to which have been bound antibodies, by means of covalent bonds, against the protein or polypeptide to be determined, wherein a certain quantity of the protein or polypeptide is labeled with a radioactive isotope, whereupon the particles, subsequent to the reaction between the protein or the polypeptide and the antibodies attached to the particles are separated from the sample liquid and the radioactivity of the particle material and/or in the liquid is determined.

Abstract: Method for determining vitamin B.sub.12 in aqueous samples by contacting said sample with radioactivity labelled vitamin B.sub.12 and with particles of water insoluble polymers to which substances capable of binding vitamin B.sub.12 have been bound, thereafter separating said particles and determining the radioactivity.