No there's no difference. At any time, means at any time, right?There is a diffrence in the rules between qualifing and race.
Rules on fuel
Article 6.6.2 of the technical regulations: "Competitors must ensure that a one litre sample of fuel may be taken from the car at any time during the event.
"Except in cases of force majeure (accepted as such by the stewards of the meeting), if a sample of fuel is required after a practice session the car concerned must have first been driven back to the pits under its own power."