Thesis (doctoral)--University of Erlangen-Nurnberg, 2000. / Cover title. Includes bibliographical references (p. 161-170) and index.

Zugl.: Darmstadt, Techn. University, Diss.

Introduction Radiometals are finding more and more applications in molecular imaging and targeted therapy. For PET imaging, all the novel radiometals are directly or indirectly produced on cyclotrons. Key step in their production is achieving proper radionuclidic, radiochemical and chemical purity, as well as high specific activity. Automation of the process enhances reproducibility, shortens necessary operations and decreases radiation burden. We have, therefore, developed universal radio-metal automated laboratory workbench (RALW) that is focused on separation processes from solid and liquid (solution) targets via solid phase extraction (SPE). Material and Methods RALW is versatile platform for separation, formulation and simple labeling processes. The following FIG. 1 displays its basic scheme. RALW´s main parts are: two reactors, two selec-tors, peristaltic pump, 3/2 way valves, and separation column. Prime reactor R1 is designed to carry out several functions. It can transport solid target material from shielding container to process position, or handle liquid target filling. In both cases, the reactor is leakagefree up to 5 bars. There are 4 positions available to bring solvents to the reactor 1 or applying on a SPE column according to the separation sequence with use of peristaltic pump. Smart software allows for collecting defined fractions leaving the column, e.g. enriched target matrix and the desired radionuclide, by monitoring activity profile and controlling the splitting valves. The system also minimizes losses during transport of the solvents/fractions to the reactor R2 and the software also controls final volume settings (activity concentration) of the product. Up to three positions are available for bringing solvents/solutions to the reactor R2 for formulation or simple labeling steps like chelation. The system’s hardware is driven by a PLC and I/O cards. The PLC is placed outside the module to avoid radiation damage. The module, PLC and host PC communicate via an Ethernet cable. This solution significantly reduced number of cables connecting the module with other component in the control chain. The PLC is controlled via host PC equipped with userfriendly interface. Results and Conclusion The presented RPLW system is rather versatile tool for separation of metal radionuclides and simple postprocessing (formulation/labelling) of the product in stable environment and easy control mechanisms. The RPLW operating prototype is shown on the FIG. 2.

Introduction [11C]choline is a very effective PET radiopharma-ceutical for the study of prostate cancer. To support the increasing demand for [11C]choline, several different synthetic approaches have been described in the literature, including different automated production methods using remote-controlled synthesis modules [1–4]. The most popular method uses a C18 Sep-Pak as solid support for methylation and, subsequently, a CM Sep-Pak for purification [2]. We report an optimized method for producing [11C]choline using only one CM Sep-Pak for both reaction and purification as was shown in the literature [4]. For synthesis of [11C]choline we used two modules Tracerlab FXC for preparation of methylation reagent [11C]CH3I and GPF-101 for [11C]choline synthesis. Material and Methods TracerlabFXC GE, GPF-101 Veenstra Instrument, 2-(dimethylamino)-ethanol (DMAE) ABX, Sep-Pak Light Accell Plus CM cation-exchange cartridges Waters used without conditioning, precursor 50 µL of DMAE dissolved in 25 µL of ethanol and loaded on a CM Sep-Pak. Schematic diagram of the automated system for the production of [11C]choline is given below. [11C]CH4 was produced in two standard Nitra target IBA irradiation of mixture 90 % N2/10 % H2 with 15 MeV protons using dual beam. Results and Conclusion [11C]CH4 was prepared in the targets and connected with Tracerlab FXC. [11C]CH3I was pre-pared in a loop in which allowed to react of elemental iodine at a temperature 720 oC. Con-version to [11C]CH3I usually is around 50% uncorrected activity. Activity is within the range 15–18 GBq of [11C]CH3I and time of production 10 min. Synthesis of [11C]choline is based on the reaction DMAE with [11C]CH3I on a Accell Plus CM cation-exchange column which serves both as a support for reaction and for separation of choline from DMAE by ethanol washing. The basic parameters are shown in TABLE 1. Beam current 2X 20 µA Irradiation time 30 min DMAE 50 µl Synthesis time from EOB 25 min Absolute yield without correction 6.6 GBq Radiochemical purity > 99 % Residual DMAE in product < 5 ppm Ethanol < 1000 mg/L pH 4.5–8.5 TABLE 1. Reaction parameters and result of production of [11C]choline syntheses Conclusion We have applied a simple synthesis method for [11C]choline preparation using automated commercial equipments with one column used both for reaction and separation purpose. The main advantage of using one column is lower contamination of the product [11C]choline with DMAE. When for synthesis of [11C]choline two columns C18 for synthesis and CM for separation is used, higher contamination of DMAE can be found in the product due to a release of DMAE from C18 column.

No description available.

Zugl.: Bielefeld, Univ., Diss., 2007

Zugl.: Ilmenau, Techn. University, Diss., 2005.

Zugl.: Saarbrücken, Univ., Diss., 2006

Zugl.: Darmstadt, Techn. Universiẗat, Diss.

Zugl.: München, Techn. Univ., Diss., 2006 u.d.T.: Schuller, Björn: Automatische Emotionserkennung aus sprachlicher und manueller Interaktion