On-Column Fluorescence Detector for Open-Tubular Capillary Liquid Chromatography
On-Column Fluorescence Detector for Open-Tubular Capillary Liquid Chromatography
复制标题
用于开管毛细管液相色谱的柱上荧光检测器
DOI：
10.1021/ac00267a043
复制
发表时间：
1984
影响因子：
7.4
通讯作者：
J. Jorgenson
中科院分区：
文献类型：
--
作者：
E. Guthrie;J. Jorgenson
The design and construction of an on-column fluorescence detector specifically suited for open-tubular capillary liquid chromatography are presented. Some advantages of using a portion of the chromatographic column for the detector flow cell are discussed. An Inherent sensitivity advantage of de-tectors operating on a partitioning region of the chromatographic column Is also discussed. The detection limit for perylene, a representative fluorophor, Is 10 pg injected on column. The detector response Is linear over a tested range approaching 4 orders of magnitude.During the lastfew years a great deal of research interest has beencentered on improving liquid chromatography (LC) column efficiency. Theoretical and experimental evidence has supported the pursuit of smaller column diameters, either small bore packed columns, packed capillary columns, or open tubular capillary columns (1). The columns of this type re-ported in the literature have diameters ranging from tenths of a millimeter for thesmall bore packed columns down to micrometers for open tubular columns. Knox and Gilbert (2) have predicted that open-tubular LC columns will have to have internal diameters in the range of 10-30 µ to produce efficiencies comparable to packed col-umns. Jorgenson and Guthrie (3) have predicted that the optimum open-tubular capillary LC columns will be approx-imately 2 µ internal diameter, 2 m long, and generate in excess of 106 theoretical plates. The internal volume of such a column will be only 6 nL. Extending the calculations of Jorgenson and Guthrie, a chromatographic peak of 106 theoretical plates and a capacity factor of 10 under optimal op-erating conditions would elute in a peak volume of only 0.3 nL (4). Commerciallyavailable LC detectors have cell volumes as small as a few tenths of a microliter. When this detector volume is compared to the predicted peak volume just calculated for an “optimum” capillarycolumn, it becomes clear that detector technology is a limiting factor confronting development of open-tubular columns. There are different ways to confront this impasse. The simplest approach is to use make-up flows to decrease the residence time of the effluent in the detector cell. This method is somewhat unsatisfactory since make-up flows inherently decrease sensitivity by diluting thesolute concentration at the detector. As an alternative, existing LC detectors could be miniaturized to reduce their cell volumes. The literature contains miniaturized UV detectors by Hirata, Novotny, Tsuda, and Ishii (4), by Krejci, Tesarik, and Pajurek (5), by Ishii and Takeuchi (6), and by Tsuda, Hibi, Nakanishi, Takeuchi, and Ishii (7), a miniaturized fluorescence detector by Hirata and Novotny (8), a laser-induced fluorescence de-tector by Folested, Johnson, Josefason, and Galle (9), and miniaturized electrochemical detectors by Hirata, Lin, Novotny, and Wightman (10), by Slais and Krejci (11), andby Novotny (12). Finally, new, sensitivedetection methods for LC could be developed. New LC detectors of this type include the flame photometric detector (FPD) by McGuffin and
