Fig. 2.

TLC-ARG analysis for optimising SPE semipurification of the ¹⁸F-intermediate. a and b TLC-ARG images of an SPE waste solution (a) and methanol eluent (b) when the reaction mixture was diluted with water. The ¹⁸F-intermediate was observed in the waste solution (arrow); c and d TLC-ARG images of an SPE waste solution (c) and methanol eluent (d) when the reaction mixture was diluted with 25% acetonitrile