1. Transport lines between the 18 O- H 2 O/[ 18 F]F- target and the synthesis device are a potential source of 19 F contamination in synthesis of 18 F- labelled radio- pharmaceuticals. 18 F was produced from highly enriched 18 O- H 2 O in a niobium target chamber. The irradiated water, containing ~37 GBq (1 Ci) is transported through either PEEK, PTFE, ETFE or PP tubes to the hot cell where the synthesis device is situated. The transport distance is ~40 m. [ 19 F]fluoride content and radioactivity of the total water volume and sample volume is measured. Synthesis of Fluciclatide is used as a model synthesis to show the incorporation of 19 F into the synthesis end product. The use of fluorinated polymers as material for the transport line of [ 18 F]fluorine- containing target water affects the radiopharmaceutical quality, i.e. specific radioactivity in a detrimental manner. Transport lines as a source of 19 F in production of 18 F-labelled radiopharmaceuticals Johan Rajander 1 ; Julian Grigg 2 ; Nina Sarja 1 ; Jussi Aromaa 1 ; Stefan Johansson 1 ; Olli Eskola 3 ; Tapio Viljanen 3 ; Esa Kokkomäki 3 ; Sarita Forsback 3 ; Jörgen Bergman 1,3 ; Sajinder Luthra 2 ; Olof Solin 1,3 1 Accelerator Laboratory, Turku PET Centre, Åbo Akademi University, Åbo, Finland; 2 GE Healthcare, Amersham, UK; 3 Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland Using PTFE and ETFE transport line tubing, a clear elevation (approximately three times) of Fluciclatide concentration was seen compared to PEEK or PP lines (Figure 2). The water transport is very similar for all four tubing materials, the target water reaches the hotcell, 40 m away, after about 8 min (Figure 3). The 18 O enriched water from Rotem Industries Ltd. is irradiated in a niobium target chamber for about 40 minutes with 40 µA under a pressure of 40 bar to give 37 GBq (~1 Ci) 18 F. The irradiated water is transported 40 m to the hot cells in 0.75 mm ID tubes. For the transport a peristaltic pump with a flow rate of ~5 ml/min is used. Four different tubing material were tested; PEEK, PP, PTFE and ETFE. After the transport the water, 2.2 mL target water + 2.8 mL DI water for rinsing the tube, is collected in a vial before it goes into the synthesis device. From the vial about 1 mL of the irradiated water is taken for further measurements of 19 F in the incoming water and for activity determination (Figure 1). The rest of the water, 4 mL, is directed into the synthesis device, a GE FASTlab ® synthesizer. Synthesis of Fluciclatide is used as a model synthesis to show the incorporation of 19 F into the synthesis end product. The water transport through the tubings was monitored with five gamma radiation detectors (large area photodiodes) from D-Pace placed along the transport line. Variable levels of stable [ 19 F]fluorine-containing products are observed from the production of [ 18 F]fluorine-labelled radio- pharmaceuticals. In practise this can be seen as a variability of the specific radioactivity (SA) of these drugs, occasionally resulting in even unacceptably low SA. We have studied the role of materials used in transport tubings on 19 F content in irradiated target water. Particular attention is directed to non-fluorinated vs. fluorinated polymers as tubing material [1-4]. INTRODUCTION MATERIALS AND METHODS RESULTS REFERENCES Figure 1. Fastlab ® synthesizer with a balance for measurements of incoming water, on top. ABSTRACT CONTACT Johan Rajander Turku PET Centre Email: johan.rajander@abo.fi Website: www.turkupetcentre.fi 1.Fuchtner et al., (2008) Nuklearmedizin, 47: 116-9; 2.Berridge et al., J Label Comp Radiopharm 2009, 52, 543; 3.Link et al., (2012), Proc 14th Int Workshop Targ, 27; 4.Solin et al. (1988), Appl Radiat Isot 39(10) 1065-71. Figure 2. HPLC-analysis of Fluciclatide concentration and SA when using various transport tubing materials. Figure 3. The transport line from the cyclotron target to the synthesis device with the radiation detectors placements (up) and the respective detectors response (down).