Op. 2, Variations in B♭ major
Op. 10, 12 Etudes
Op. 11, Concerto in E minor
Op. 21, Concerto in F minor
Op. 22, Polonaise in E♭ major
Op. 24, 4 Mazurkas
Op. 25, 12 Etudes
Op. 26, 2 Polonaises
Op. 27, 2 Nocturnes
Op. 28, 24 Preludes
Op. 30, 4 Mazurkas
Op. 35, Sonata in B♭ minor
Op. 50, 3 Mazurkas
Op. 63, 3 Mazurkas
Op. 64, 3 Waltzes
(Op. 4), Sonata in C minor
Op. 12, Variations in B♭ major
The absence of a 
at the end of a piece (in this case, Introduction) is quite a frequent phenomenon in Chopin's works. Generally, it means that the pedal should be pressed throughout the entire final fragment or that it should be gradually released (the so-called diminuendo pedal). According to us, in the discussed case, holding the pedal pressed to the end results in a very good sound effect; alternatively, the pedal can be gradually released throughout bar 31 to be pressed again (optionally) in bar 32.
Compare the passage in the sources »
category imprint: Source & stylistic information
issues: No pedal release mark
notation: Pedalling