## 3 Results and Discussion  
The methods described in this work have been used successfully for several months for the cyclotron production and chemical separation of \({}^{89}\)Zr. Typically, after the chemical separation was completed using the automated module, a dose calibrator was used to measure the activity of \({}^{89}\)Zr collected in the product and waste vials. To reduce radiation dose, the system was allowed to decay for one week before measuring the dissolution vessel, which still contained the irradiated Nb target holder, and the intact column assembly, which still included the resin, frits, and glass wool. The radioactivity measured for all four major module components was decay-corrected to the end-of-bombardment (EOB) time for each production. The decay-corrected activities were summed to give an estimated total radioactivity of \({}^{89}\)Zr produced in each cyclotron bombardment. This estimate neglects any activity that was lost in tubing, valves, _etc._, but it allows us to compare the performance of the automated chemical separation for productions with different starting activities. The majority (74% \(\pm\) 16%) of \({}^{89}\)Zr was collected in the product vial and the largest loss of activity was to the column (18% \(\pm\) 15%), which was greater than either the waste vial (4% \(\pm\) 10%) or the dissolution vessel (3% \(\pm\) 3%), as shown in Figure 5. The percentage of \({}^{89}\)Zr activity collected in the product vial is the recovery rate of the chemical separation that was carried out using the automated module and is an important performance indicator for the separation process. Our average recovery was significantly lower than other publications about \({}^{89}\)Zr production (see ESI). In some cases this may be a result of us only collecting one elution instead of multiple fractions; otherwise, it may be because the stock of hydroxamate resin became less effective at binding Zr if it was stored for too long. We chose to make a stock of the resin for simplicity to avoid functionalizing a new batch of resin for each production. Characteristics for ten selected productions are shown in Table 3, including cyclotron parameters, predicted and estimated yields from the cyclotron, and ESA. All targets were bombarded with \(\sim\)14.7 MeV protons. In this current work, Nb was selected as the material for the target holder primarily because of its chemical inertness toward HCl and its high melting temperature. The Nb target holders have been irradiated up to 15 uA without significant alterations of target or target holder. Since the same beam current, beam energy, and foil thickness were used for all productions in this work, the bombardment time (_t_) was the only bombardment parameter that was adjusted to control the amount of activity produced in the cyclotron. The maximum bombardment time in this work was 4 h, which was equivalent to 60 uA\(\cdot\)h. The parameters for comparable publications varied widely. Excluding the Y\({}_{2}\)O\({}_{3}\) pellet targets, only one publication [26] used a foil that was close to ours in thickness. Also, the beam current, bombardment time, and uA\(\cdot\)h all varied widely across publications. Not surprisingly, the Y\({}_{2}\)O\({}_{3}\) targets used lower currents, presumably because of reduced heat transfer, while the sputtered targets received high beam current for long bombardment times. The predicted activity produced from each cyclotron bombardment is given in Table 1 and was calculated using published empirical cross-section data for the \({}^{\mathrm{nat}}\)Y(\(p\),\(n\))\({}^{89}\)Zr reaction [29, 30, 31, 32, 33, 34, 35, 36] (see ESI)