Sarah Sjöström was unsurprisingly the fastest in her heat with a time of 25.30 and is through to the semi-finals.
Louise Hansson was second in her heat, 25.88, and she is also in - but Sara Junevik, who came third with a time of 25.96 after Hansson, is excluded from advancing despite her time due to a rule that means that only two from each nation can move on.
Belgian Roos Vanotterdijk, who was eighty hundredths slower than Junevik, went further from the heat instead.
- I think it is positive that more people are allowed to swim.
But it is negative that only two are allowed to move on, says Frölander.
The rule means that nations without mutual competition can swim more tactically during the trials, he points out, and also believes that it will be strange that the fastest swimmers are not allowed to compete for the medals.
- I think that the three best in Europe, if they come from Italy or Sweden or somewhere else, should get a medal and stand on the podium, he says.
Just Junevik, Hansson and Sjöström are medal candidates.
- It could be a Swedish triple if everyone had been allowed to swim the final, says Frölander.
The semi-finals will be decided starting at 18.42 this evening.