The molar activity of [18F]fluoride was determined by HPLC of sulfonyl fluorides, which have high UV absorbance and are formed exclusively from sulfonyl chlorides and [18F]fluoride in aqueous solution. The measurable limit of sulfonyl fluorides is as low as 0.1 ppm, allowing measurements up to the theoretical molar activity of [18F]fluoride. The method was validated with standard solutions of fluoride, and provides a convenient way to measure molar activity of [18F]fluoride using only HPLC without specialized equipment.
- Molar activity
- Sulfonyl fluoride