creators_name: Macka, M creators_name: Andersson, P creators_name: Haddad, PR creators_id: Mirek.Macka@utas.edu.au creators_id: creators_id: Paul.Haddad@utas.edu.au type: article datestamp: 2008-05-07 07:01:40 lastmod: 2008-09-11 01:53:30 metadata_visibility: show title: Linearity evaluation in absorbance detection: The use of light-emitting diodes for on-capillary detection in capillary electrophoresis ispublished: pub subjects: 250000 subjects: 250401 subjects: 250400 full_text_status: restricted keywords: Capillary electrophoresis • Light-emitting diodes • On-capillary absorbance detection • Linearity note: Copyright © 1996 VCH Verlagsgesellschaft mbH abstract: A model which takes into account both stray light and polychromatic light was used to predict and evaluate linearity in on-capillary detection in capillary electrophoresis (CE). According to the model the stray light is the major factor which determines linearity under typical CE operating conditions. By calculating theoretical absorbance versus concentration plots, the influence of different levels of stray light and polychromatic light on linearity is demonstrated. Experimentally, six light-emitting diodes (LEDs) in the range from 563 to 654 nm were examined as light sources for on-capillary detection in CE. Fitting theoretical curves to measured linearity plots enabled determination of the values of both effective path lenght and stray light for a particular detection system. The detector linearity for the four LEDs was compared to mercury and tungsten lamps used with interference filters. For potassium permanganate as the test compound, the linear range for a 563 nm LED was two times greater than that for a mercury lamp operated at 546 nm. The relatively poor linearity of the mercury lamp detector is explained by its high level of stray light. The noise of the LED563-based detector was the same as for the mercury lamp, whereas the other LEDs of higher light intensity gave approximately half the noise of the mercury lamp. The lowest noise level of 3 × 10-5 AU was obtained for the LED at 554 nm (determined at a detector time constant of 0.1 s). date: 1996-12 date_type: published publication: Electrophoresis volume: 17 number: 12 pagerange: 1898-1905 id_number: 10.1002/elps.1150171215 refereed: TRUE issn: 0173-0835 official_url: http://www3.interscience.wiley.com/journal/110470873/abstract referencetext: 1 Dasgupta, P. K., Bellamy, H. S., Liu, H., Lopez, J. L., Loree, E. L., Morris, K., Petersen, K., Mir, K. A., Talanta 1993, 40, 53-74. 2 Bruno, A. E., Maystre, F., Krattiger, B., Nussbaum, P., Gassmann, E., Trends Anal. Chem. 1994, 13, 190-198. 3 Tong, W., Yeung, E. S., J. Chromatogr. 1995, 718, 177-185. 4 Encyclopedia of Lasers and Optical Technology, Academic Press, San Diego 1991, p. 423. 5 Skoog, D. A., Leary, J. J., Principles of Instrumental Analysis, Harcourt Brace College Publishers, Orlando 1992, Chapter 7, pp. 123-131. 6 Ingle, J. D., Crouch, S. R., Spectrochemical Analysis, Prentice Hall, Englewood Cliffs 1988, p. 374-380. 7 Hauser, P. C., Chiang, D. W. L., Talanta 1993, 40, 1193-1200. 8 Hauser, P. C., Rupasinghe, T. W. T., Cates, N. E., Talanta 1995, 42, 605-612. 9 Walbroehl, Y., Jorgenson, J. W., J. Chromatogr. 1984, 315, 135-143. 10 Sepaniak, M. J., Swaile, D. F., Powell, A. C., J. Chromatogr. 1989, 480, 185-196. 11 Wang, T., Hartwick, R. A., J. Chromatogr. 1989, 462, 147-154. 12 Bruno, A. E., Gassmann, E., Periclé, N., Anton, K., Anal. Chem. 1989, 61, 876-883. 13 Bruin, G. J. M., Stegeman, G., Van Asten, A. C., Xu, X., Kraak, J. C., Poppe, H., J. Chromatogr. 1991, 559, 163-181. 14 Standard Practice for Testing Fixed-Wavelength Photometric Detectors Used in Liquid Chromatography, ANSI/ASTM E685-79, American Society for Testing and Materials, Philadelphia, PA 1979. 15 Cassidy, R., Janoski, M., LC. GC 1992, 10, 692-696. 16 Fawlis, L. A., Scott, R. P., J. Chromatogr. 1963, 11, 1-10. 17 Dorschel, C. A., Ekmanis, J. L., Oberholtzer, J. E., Warren, Jr. R. V., Bidlingmeyer, B. A., Anal. Chem. 1989, 61, 951A-968A. 18 Annual Book of ASTM Standards, American Society for Testing and Materials, Philadelphia 1988, 14.01, pp. 149-158. 19 Fanali, S., Ossicini, L., Foret, F., Boek, P., J. Microcolumn Sep. 1989, 1, 190-194. 20 Wilson, J., Hawkes, J. F. B., Optoelectronics, Prentice Hall, New York 1986. 21 Macka, M., Seménková, L., Borák, J., Mikes, V., Popl, M., J. Liq. Chromatogr. 1993, 16, 2359-2386. 22 Tables of spectrophotometric absorption data of compounds used for the colorimetric determination of elements, Butterworths, London 1963, p. 337. 23 Williams, S. J., Bergström, E. T., Goodall, D. M., Kawazumi, H., Evans, K. P., J. Chromatogr. 1993, 636, 39-45. citation: Macka, M and Andersson, P and Haddad, PR (1996) Linearity evaluation in absorbance detection: The use of light-emitting diodes for on-capillary detection in capillary electrophoresis. Electrophoresis, 17 (12). pp. 1898-1905. ISSN 0173-0835 document_url: http://eprints.utas.edu.au/6277/1/147.pdf