P nitroaniline and o nitroaniline which one will be eluted first?

In chromatography, o-nitroaniline will typically be eluted first compared to p-nitroaniline. This is due to the difference in their molecular interactions with the stationary phase; o-nitroaniline has a stronger hydrogen bonding capability due to the proximity of the nitro group to the amino group, which can lead to stronger interactions with the stationary phase. Consequently, it tends to have a lower retention time in the column.