Pfizer Global Research and Development, Ramsgate Road, CT13 9NJ, Sandwich, UK.
J Chromatogr A. 2010 Jul 23;1217(30):4925-33. doi: 10.1016/j.chroma.2010.05.044. Epub 2010 May 31.
The present study focuses on the evaluation of 1.0 mm i.d. (internal diameter) columns on a commercial Ultra-High Pressure system. These systems have been developed specifically to operate columns with small volumes, typically 2.1 mm i.d., by reducing extra-column volume dispersion. The use of columns with smaller i.d. results in a reduced solvent consumption and required sample volume. The evaluation of the columns was carried out with samples containing neutral and pharmaceutical compounds. In isocratic mode, the extra-column volume produced additional band broadening leading to poor performances compared to equivalent 2.1 mm i.d. columns. By increasing the length of the column, the influence of the extra-column bandspreading could be reduced and 75,000 plates were obtained when four columns were coupled. In gradient mode, the effect of the extra-column contribution on efficiency was limited and about 80% of the performance of the 2.1 mm i.d. columns was obtained. Optimum conditions in gradient mode were further investigated by changing flow rate, gradient time and column length. A different approach of the calculation of peak capacity was also considered for the comparison of the influence of these different parameters.
本研究集中于评估商业超高压系统上 1.0mm ID（内径）的色谱柱。这些系统是专门为操作小体积的色谱柱而开发的，通常为 2.1mm ID，通过减少额外柱体积分散来实现。使用较小内径的色谱柱可减少溶剂消耗和所需样品量。使用含有中性和药物化合物的样品对色谱柱进行了评估。在等度模式下，额外柱体积产生了额外的带宽展宽，导致与等效的 2.1mm ID 色谱柱相比性能较差。通过增加柱长，可以减少额外柱带宽展的影响，当四个柱串联时，可以获得 75000 块理论塔板。在梯度模式下，额外柱贡献对效率的影响有限，可获得约 80%的 2.1mm ID 色谱柱的性能。通过改变流速、梯度时间和柱长，进一步研究了梯度模式下的最佳条件。还考虑了一种不同的峰容量计算方法，用于比较这些不同参数的影响。
