As specified before, in vivo applications require high purity material. However, due to finite spin relaxation times it is important that the purification step is rapid, and that there is no significant polarization loss during the purification procedure (due to possible rapid relaxation effects). To investigate this, the experiment was repeated three times, and in each case we compare the C polarization level of the control sample to the purified sample; the results are shown in Fig. . We can expect slight polarization loss in the purified samples as compared to the control samples due to the shorter 𝑇 1 of the purified sample in the solution state prior to signal acquisition. However, within the given errors there is no evidence that the phase transitions have any effect on nuclear spin polarization.