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Practical method of evaluation of linearity and effective pathlength of on-capillary photometric detectors in capillary electrophoresis
journal contribution
posted on 2023-05-16, 13:00 authored by Johns, CA, Miroslav MackaMiroslav Macka, Paul HaddadPaul Haddad, King, M, Paull, BThe optical characteristics of on-capillary photometric detectors for capillary electrophoresis were evaluated and five commercial detectors were compared. Plots of sensitivity (absorbance/concentration) versus absorbance obtained with a suitable testing solution yield both the linear range and the effective path length of the detector. The detector linearity is a crucial parameter when using absorbing electrolytes, such as for indirect photometric detection, and especially for highly absorbing electrolyte probe ions. The upper limits of the linear ranges (determined as 5% decline in sensitivity) for five commercial detectors ranged from 0.175 to 1.2 AU. The effective pathlength reflects the quality of the optical design of the detector and is equal to the capillary internal diameter only for a light beam passing exactly through the capillary centre, but becomes progressively shorter for imperfect optical designs. The determined effective pathlength for the five investigated detectors ranged from 49.7 to 64.6 μm for a 75 μm I.D. capillary. © 2001 Elsevier Science B.V. All rights reserved.
History
Publication title
Journal of Chromatography AVolume
927Issue
1-2Pagination
237-241ISSN
0021-9673Department/School
School of Natural SciencesPublisher
Elsevier Science BVPlace of publication
AmsterdamRepository Status
- Restricted