Abstract: A method for producing a polyether ether ketone is disclosed. The method includes the following steps: a) causing a disubstituted benzophenone of the general formula (I) to react with a benzene derivative of the general formula (II), wherein A is a carbon atom provided with a protecting group; R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, each independently of one another, are H, D, OH, X, substituted or unsubstituted C1-C5-alkyl or substituted or unsubstituted C6-C10-aryl; X is F, Cl, Br or I; Z, Z?, Z?, Z??, each independently of one another, are OH, OMe, Me(OH)m MeR13m or Me; m is 1, 2, 3 or 4; R13 is metal, alkali metal or alkaline earth metal and Me is metal, alkali metal or alkaline earth metal. Subsequently, the product formed in step a) is deprotected in step b) in order to obtain a polyether ether ketone of the general formula (III): wherein G, G?, each independently of one another, are O or C and n is an integer which is greater than 10.

Abstract: A method for producing a polyether ether ketone is disclosed. The method includes the following steps: a) causing a disubstituted benzophenone of the general formula (I) to react with a benzene derivative of the general formula (II), wherein A is a carbon atom provided with a protecting group; R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, each independently of one another, are H, D, OH, X, substituted or unsubstituted C1-C5-alkyl or substituted or unsubstituted C6-C10-aryl; X is F, Cl, Br or I; Z, Z?, Z?, Z??, each independently of one another, are OH, OMe, Me(OH)m MeR13m or Me; m is 1, 2, 3 or 4; R13 is metal, alkali metal or alkaline earth metal and Me is metal, alkali metal or alkaline earth metal. Subsequently, the product formed in step a) is deprotected in step b) in order to obtain a polyether ether ketone of the general formula (III): wherein G, G?, each independently of one another, are O or C and n is an integer which is greater than 10.

Abstract: A method for determining the 14C content of a gas mixture in which 14C isotopes are present as molecule constituents, is provided. The gas mixture is provided in a measuring space, wherein infrared laser radiation is supplied to the measuring space as measurement radiation. The laser radiation to be supplied to the measuring space is deflected such that it passes through the measuring space a plurality of times by interacting with the gas mixture, wherein the laser radiation is supplied to a detector, in order to determine the absorption of laser radiation by the gas mixture and therefrom determine the 14C content. For generating the laser radiation a pulsed laser is used, which as measurement radiation emits laser pulses with a pulse duration of less than 5 ?s, which are supplied to the measuring space.