Peak Compression Effects in Liquid Chromatography Examined Using Whole-Column Detection

• Main Authors: Chou, Yi-Ru, 周宜儒
• Other Authors: Yu, Tiing
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/88691164584879604355

碩士 === 國立交通大學 === 應用化學系碩博士班 === 99 === Peak compression occurred when a sample solution was injected into a liquid chromatographic column. Another compression phenomenon took place at the interface of the two mobile phases with different solvent strengths under a gradient elution. We examined both effects using a whole-column detection (WCD) system which enabled direct observations of both the spatial and temporal peak profiles during the elution. 　　The sample peak width at the column inlet was highly related to the retention factor k. The peak standard deviation on the spatial coordinate was linearly proportional to 1/(1+k) at the column position ~1 cm. The peak width might stay narrower at the column outlet for a chromatographic run of a large k compared with a run of a small k with the use of a column with good efficiency. However, the peak width of a large k might become wider at the column outlet with the use of a low-efficiency column. The plate number increase of the continuous gradient prevailed over that of the stage-wise gradient. Plate numbers for gradient elutions were calculated in this study based on analyte moving rates. The results gave significant improvements, up to four folds in some experiments, compared with the use of conventional equations.