An overview how to measure and to quantify radiolysis by the addition of quenchers and to maintain Radio-Chemical Purity (RCP) of vulnerable methionine-containing regulatory peptides is presented. High RCP was only achieved with a combination of quenchers. However, quantification of RCP is not standardized, and therefore comparison of radiolabelling and RCP of regulatory peptides between different HPLC-systems and between laboratories is cumbersome. Therefore we suggest a set of standardized requirements to quantify RCP by HPLC for radiolabelled DTPA- or DOTA-peptides. Moreover, a dosimetry model was developed to calculate the doses in the reaction vials during radiolabelling and storage of the radiopeptides, and to predict RCP in the presence and absence of quenchers. RCP was measured by HPLC, and a relation between radiation dose and radiolysis of RCP was established. The here described quenchers are tested individually as ƒ(concentration) to investigate efficacy to reduce radiolysis of radiolabelled methionine-containing regulatory peptides.

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TNO has built EBL2, an EUV exposure facility equipped with an in vacuo X-ray photoelectron spectroscopy setup (XPS) and an in-situ ellipsometer. EBL2 enables lifetime testing of EUV optics, photomasks, pellicles and related components under development in relevant EUV scanner and source conditions, which was previously not available to industry. This lifetime testing can help the industry to prepare for high volume production using EUV lithography by bringing forward information about material behavior which facilitates the development cycle. This paper describes an EUV photomask lifetime test performed at EBL2. The mask was exposed to different EUV doses under a controlled gas and temperature environment. To investigate how EUV light interacts with the mask, various analysis techniques were applied before and after EUV exposure. In-situ XPS was used to investigate elemental compositions of the mask surface. An ex-situ critical dimension scanning electron microscope (CD-SEM) and an atomic force microscope (AFM) were used to explore the impact of EUV light on critical dimensions (CD) and feature profiles. In addition, EUV reflectometry (EUVR) was used to investigate the change of reflectivity after EUV exposures. The exposure conditions are reported, as well as an analysis of the effects observed.

a Microfluidic synthesis techniques can offer improvement over batch syntheses which are currently used for radiopharmaceutical production. These improvements are, for example, better mixing of reactants, more efficient energy transfer, less radiolysis, faster reaction optimization, and overall improved reaction control. However, scale-up challenges hinder the routine clinical use, so the main advantage is currently the ability to optimize reactions rapidly and with low reactant consumption. Translating those results to clinical systems could be done based on calculations, if kinetic constants and diffusion coefficients were known. This study describes a microfluidic system with which it was possible to determine the kinetic association rate constants for the formation of [ the reaction channel is increased to over 500 μm. These results show that a continuous, microfluidic system can become a viable alternative to the conventional, batch-wise radiolabelling technique.