Effect of an anionic polymer on the separation of cationic molecules by capillary electrophoresis with conductivity detection

Determination of low‐molecular‐mass quaternary ammonium compounds by capillary electrophoresis and hyphenation with mass spectrometry

“…Indirect detection of aliphatic quats has been investigated in 20 mM sodium fluoride containing 1 mM triethanolamine and 10% acetonitrile [34], but detection limits were only between 5 and 10 mg/L and therefore considerably poorer than in indirect photometric detection. Similar results have been obtained in a CHES/LiOH buffer [28]. Users of conductivity detectors sometimes experience poor stability of the signal since buffer components may lack compatibility with the electrodes.…”

“…Sodium dodecyl sulfate may be added to improve peak resolution due to the formation of ion pairs. Poly(sodium 4-styrenesulfonate) has also been investigated as additive for manipulation of separation selectivity [28]. Since the analytes are lacking a chromophore, indirect UV detection is frequently used.…”

Determination of morphine and codeine in urine using poly(dimethylsiloxane) microchip electrophoresis with electrochemical detection

“…2, curve 1). It was reported that surfactants, organic modifiers and cyclodextrins could be used as additives of the electrophoresis buffer to enhance the selectivity of similar compounds [26][27][28][29][30]. Thus many additives including surfactants, organic modifiers and cyclodextrin were tested in order to obtain good separation efficiency of morphine and codeine.…”

“…This provided a confirmation that they can modify the electroosmotic flow (EOF) and improve the separation. Several papers had indicated the effective use of organic modifiers in CE [28,31,32]. Acetonitrile, methanol and ethanol were tested and acetonitrile exhibited the best performance.…”