Long chain alkylamines such as TBA (Tributylamine) and TPA (Tripropylamine) were analysed by ion-pair method using RI detector. However, this method is not so sensitive. Using IC YK-421 with nitric acid aqueous solution/ acetonitrile eluent and a conductivity detector, highly sensitive analysis of long chain alkylamines can be realized.The effect of acetonitrile concentration on elution volume of alkylamines are shown. When the acetonitrile concentration is lower than 50%, the components which have shorter chain elute faster. And, to the contrary, when the acetonitrile concentration if higher than 50%, the components which have longer chain elute faster. The reason of the difference can be explained by the the difference of the separation mode. When acetonitrile concentration is lower than 50%, the separation mode is hydrohorbic interaction, and, when acetonitrile concentration is higher than 50% the separation mode is ion exchange.
Sample : Alkylamines
Column : Shodex IC YK-421 (4.6mmID*125mm)
Eluent : 3mM Nitric acid aq./CH3CN
Flow rate : 1.0mL/min
Detector : Shodex CD
Column temp. : 40°C