CHROMATOGRAPHY, Vol. 34 (2013), No. 1, pp. 33-40
Original
Separation and determination of dopamine and epinephrine in serum by capillary electrophoresis with inkjet introduction system
Ying Weng, Hulie Zeng, Yuri Nakagawa, Saori Ikeda, Fengming Chen, Hizuru Nakajima, Katsumi Uchiyama
Tokyo Metropolitan University,
Minamiosawa, Hachioji, Tokyo 192-0397, Japan
Abstract:
A new inkjet sample introduction method was developed for capillary electrophoresis (CE). This system could control the exact volume of ejected liquid with high accuracy and precision at the picoliter level. The single droplet volume of 1×10−6 mol/L dopamine (DA) in 1×10−2 mol/L borate buffer and in the 40 times diluted serum were 240 pL and 243 pL, respectively. Sample droplets were ejected by stressing a piezoelectric slice stuck on the extrusion chamber. The pulse voltages were applied to the piezoelectric slice which made the slice deformed. Using this method, DA and epinephrine (EP) were separated and the concentration of EP in serum was determined at 5.88×10−7 mol/L, DA was not detected. The recovery (n＝3) of EP and DA added to serum were in the range of 95.8-98.7%, and 97.5-103.4% respectively, which showed good accuracy and reproducibility.
Keywords:
Inkjet, Exact sample introduction for CE, Dopamine, Epinephrine.
