Inductance and Coil Diameter for High Frequency Transformer?
Yes, you may be able to use a transformer but also consider this as an option: -



It's an ADC isolated from ground (UL recognition: 2500 V rms for 1 minute per UL 1577) by the ADuM5401. The ADC is both powered by the ADuM5401 and talks to ground referenced equipment via SPI through that device's isolated ports.

So, using a precision voltage divider you can get better accuracy compared to a transformer. Anyway, it's food for thought should you want a back-up plan to the transformer idea.