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Ultraviolet absorbance detector based on a high output power 235 nm surface mounted device-type light-emitting diode


Lam, SC and Coates, LJ and Gupta, V and Wirth, H-J and Gooley, AA and Haddad, PR and Paull, B, Ultraviolet absorbance detector based on a high output power 235 nm surface mounted device-type light-emitting diode, Journal of Chromatography A, 1631 Article 461540. ISSN 0021-9673 (2020) [Refereed Article]

Copyright Statement

2020 Elsevier B.V. All rights reserved.

DOI: doi:10.1016/j.chroma.2020.461540


A new miniaturised capillary flow-through deep-UV absorbance detector has been developed using a microscale surface mounted device- type light-emitting diode (LED) (Crystal IS OPTAN 3535-series), emitting at 235 nm and with a half-height band width of 12 nm, and a high-sensitivity Z-shaped flow-cell. Compared with a previously reported TO-39 ball lens LEDs emitting at 235 nm, the new generation LED produced a 20-fold higher optical output and delivered up to 35 times increase in external quantum efficiency (EQE). The Z-cell was based on a reflective rectangular optical path with cross-sectional dimensions of 100 x 100 m and a physical optical pathlength of 1.2 mm. Inclusion of UV transparent fused-silica ball lenses, between the SMD and the Z-cell, improved light transmission by a factor of 9 and improved the detector signal-to-noise ratio by a factor of 2.2, at the same input current. The detector was housed within an Al-housing fitted with a cooling fan and demonstrated excellent linearity with stray light down to 0.06%, and an effective pathlength of 1.1 mm (92% of nominal pathlength). The resultant detector was fitted successfully into a briefcase-sized portable capillary HPLC system, and practically demonstrated with the detection of a mixture of 13 test compounds at the sub-mg L−1 level in <5 min using gradient elution.

Item Details

Item Type:Refereed Article
Research Division:Chemical Sciences
Research Group:Analytical chemistry
Research Field:Separation science
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the chemical sciences
UTAS Author:Lam, SC (Mr Shing Chung Lam)
UTAS Author:Coates, LJ (Mr Lewellwyn Coates)
UTAS Author:Gupta, V (Dr Vipul Gupta)
UTAS Author:Wirth, H-J (Dr Hans-Jurgen Wirth)
UTAS Author:Gooley, AA (Dr Andrew Gooley)
UTAS Author:Haddad, PR (Professor Paul Haddad)
UTAS Author:Paull, B (Professor Brett Paull)
ID Code:151653
Year Published:2020
Web of Science® Times Cited:7
Deposited By:Plant Science
Deposited On:2022-08-02
Last Modified:2022-09-06

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