电泳芯片结构和芯片电泳分离操作参数的模拟、优化和实验验证

Simulation and Optimization of Parameters for Electrophoresis Microchip Design and Operations and Its Validation by Experiments

选择了L-精氨酸和L-苯丙氨酸为分离样品体系,根据电泳实验提出样品基本参数,通过模拟计算考察了进样管道宽度和进样时间对进样方差的贡献;根据分离度与分离长度拟合曲线确定电泳芯片的有效分离长度;对化学发光柱后衍生管道施加的夹流电压进行了模拟优化,得出氨基酸体系分离分析的电泳芯片设计方案和操作参数为：进样管道宽度为分离管道宽度的1/2,简单进样充样时间应大于5 s,分离管道有效分离长度为30 mm,衍生夹流比1.0～1.6.根据模拟优化结果提出了电泳芯片设计方案,采用整体浇注法制作带有柱后衍生反应器的PDMS电泳芯片,按照模拟计算提出的电压操作参数实现了精氨酸和苯丙氨酸样品体系的准确进样、芯片电泳分离和柱后衍生化学发光检测.电泳过程模拟结果和实验结果相结合,考察了柱后衍生对样品谱带展宽的影响,简单进样过程样品泄露引起的谱峰拖尾现象,并讨论了夹流进样法对减小进样方差和抑制样品泄露的贡献.

For arginine and phenylalanine sample system, the contributions of sample channel width and injection time to sampling variance were investigated and optimized by simulation using CoventorWare software. According to the resolution versus separation length regression curves, the length of separation channel was determined and the influence of turns employed in separation channel was discussed. In terms of the concentration distribution curve of sample plug in the derivative cross, the applied voltage during chemiluminescence derivatization in reaction channels was optimized. The optimized chip design and operation were as follows： injection channel was half the width of separation channel; during simple injection the loading time was 5 s ; the efficient length of separation was 30 mm ; focusing ratio should be in the range of 1.0 - 1.6 ; tums employed in separation channel would not bring significant band spreading for this amino acids sample system. According to the simulation results applying CoventorWare, the polydimethyl-siloxane （PDMS） electrophoresis microchip containing post-column reactor was fabricated using monolithic pouring approach, on which with the operation parameters obtained by calculation, the accurate injection, electrophoresis separation, and chemiluminescence detection were successfully performed. The post-column induced band spreading, simple injection induced peak tailing and pinched injection were also investigated, comparing the simulation with experimental results. The pinched injection that leads to less injection variance and sample leakage inhibition was also employed and discussed.