Consider the following statements related to the measurement of zeta potential:

1- Electrophoresis relies on observing the motion of particles under an applied electric field to estimate the zeta potential of particulates.
2- Streaming potential/current measurements are essential for determining the zeta potential of porous bodies and flat surfaces.
3- Nuclear Magnetic Resonance (NMR) is a standard method for directly measuring the zeta potential in colloidal dispersions.
4- Dynamic Light Scattering (DLS) can be adapted to measure electrophoretic mobility, which is then used to calculate the zeta potential.
Which of the above statements are correct?