Shen H, Lada M W, Kennedy R T
Department of Chemistry, University of Florida, Gainesville 32611-7200, USA.
J Chromatogr B Biomed Sci Appl. 1997 Dec 19;704(1-2):43-52. doi: 10.1016/s0378-4347(97)00436-2.
A method based on microdialysis sampling and capillary liquid chromatography with electrochemical detection that allows in vivo monitoring of met-enkephalin with 5-min temporal resolution is described. Sampling was achieved using a concentric microdialysis probe made from polycarbonate membrane material with a 20 kDa cut-off. This probe had an in vitro relative recovery for met-enkephalin of 63% at a dialysis flow-rate of 0.6 microl/min. Separations were performed using 7 cm x 25 microm I.D. fused-silica capillary columns packed with 5 microm Alltima C18 particles. A carbon fiber microelectrode was used as the detector electrode. The mass detection limit for met-enkephalin with this system was 40 amol. With on-column preconcentration, up to 2 microl of sample could be loaded onto the column resulting in concentration detection limits as low as 20 pM for met-enkephalin. Direct injection of dialysate, collected at 5-min intervals, allowed determination of met-enkephalin concentrations in the rat globus pallidus under basal and K+-induced depolarization conditions.
本文描述了一种基于微透析采样和毛细管液相色谱-电化学检测的方法，该方法能够以5分钟的时间分辨率对甲硫氨酸脑啡肽进行体内监测。使用由聚碳酸酯膜材料制成的具有20 kDa截留分子量的同心微透析探针进行采样。在透析流速为0.6微升/分钟时，该探针对甲硫氨酸脑啡肽的体外相对回收率为63%。使用内径为25微米、长度为7厘米的填充有5微米Alltima C18颗粒的熔融石英毛细管柱进行分离。使用碳纤维微电极作为检测电极。该系统对甲硫氨酸脑啡肽的质量检测限为40阿摩尔。通过柱上预浓缩，最多可将2微升样品加载到柱上，从而使甲硫氨酸脑啡肽的浓度检测限低至20皮摩尔。以5分钟的间隔直接进样收集的透析液，可测定基础和钾离子诱导的去极化条件下大鼠苍白球中甲硫氨酸脑啡肽的浓度。
