Six orders of magnitude dynamic range in capillary electrophoresis with ultrasensitive laser-induced fluorescence detection

TALANTA

卷:80

Article

Whitmore, Colin D.¹  Essaka, David¹  Dovichi, Norman J.¹ 

[1] Univ Washington, Dept Chem, Seattle, WA 98195 USA

关键词: Capillary electrophoresis;    Dynamic range;    Linear range;    Laser induced fluorescence;   

DOI  :  10.1016/j.talanta.2009.07.060

来源: Elsevier

【 摘 要 】

An ultrasensitive laser-induced fluorescence detector was used with capillary electrophoresis for the study of 5-carboxy-tetramethylrhodamine. The raw signal from the detector provided roughly three orders of magnitude dynamic range. The signal saturated at high analyte concentrations due to the dead time associated with the single-photon counting avalanche photodiode employed in the detector. The signal can be corrected for the detector dead time, providing an additional order of magnitude dynamic range. To further increase dynamic range, two fiber-optic beam-splitters were cascaded to generate a primary signal and two attenuated signals, each monitored by a single-photon counting avalanche photodiode. The combined signals from the three photodiodes are reasonably linear from the concentration detection limit of 3 pM to 10 mu M, the maximum concentration investigated, a range of 3,000,000. Mass detection limits were 150 yoctomoles injected onto the capillary. (C) 2009 Elsevier B.V. All rights reserved.

【 授权许可】

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