We performed molecular dynamics simulations on sodium dodecyl sulfate (SDS) monolayer at the water/carbon tetrachloride and water/vapor interfaces. We observed that the tails are slightly less ordered when SDS is at the water/vapor interface. Also, at the water/carbon tetrachloride interface the amphiphilic molecule is less inclined with respect to the surface normal compared to the one at the water/vapor interface. We also carried out investigations of the electrostatic properties and surface tension of the water/carbon tetrachloride interface in the presence of the SDS monolayer with and without the dipole correction term in the Ewald sum. We observed that an inclusion of the correction term makes a difference in quantitative results.