Why do almost no CE methods use an internal Standard

[MSCHemist]

Why do so few CE methods use an ITSD? I've read quite a few and see almost none. I would think with the variability of how much material gets injected it would be very beneficial.

[DeusEx]

I don't know, but i always try use an internal standard when developing a method. In CE is easy to have variations in injected volume (due to the low volume injected correlated with viscosity and superficial tension difference) and migration time due to almost omnipresent EOF.