(pKa1 = 2.12, pKa2 = 7.20 and pKa3 = 12.36), is a popular buffer sys- tem for CE. Considering that TGA salts at pH 7.0–9.5 or 12.7 and TGA esters at pH 6.0–9.5 are usually used in cosmetic formulations [6] and only phosphate can provide a good buffer capacity at pH higher than (pKa2 (of TGA) + 2), phosphate was chosen as a priority running buffer for the subsequent optimizations.