Sodium (23Na) is connected to tissue physiology and can be spatially resolved by MRI. Low in-vivo concentrations and short relaxation times render a quantitative determination challenging. We present a simulation method which allows synthesizing realistic 23Na MRI raw data. Thereby, most effects in typical quantification experiments on the basis of an external concentration reference can be studied. To establish a reference accuracy level, we investigate the influence of T2* decay, undersampling, TE, and TR on 23Na quantification. The presented simulations can be used for the testing and evaluation of quantitative reconstruction methods as well as to test significance in clinical studies.