Open Access Repository

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

Lam, SC, Coates, LJ, Gupta, V ORCID: 0000-0003-1458-824X, Wirth, H-J, Gooley, AA, Haddad, PR ORCID: 0000-0001-9579-7363 and Paull, B ORCID: 0000-0001-6373-6582 2020 , 'Ultraviolet absorbance detector based on a high output power 235 nm surface mounted device-type light-emitting diode' , Journal of Chromatography A, vol. 1631 , pp. 1-6 , doi:

Full text not available from this repository.


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 µm 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 Lâ1 level in <5 min using gradient elution.

Item Type: Article
Authors/Creators:Lam, SC and Coates, LJ and Gupta, V and Wirth, H-J and Gooley, AA and Haddad, PR and Paull, B
Journal or Publication Title: Journal of Chromatography A
Publisher: Elsevier Science Bv
ISSN: 0021-9673
DOI / ID Number:
Copyright Information:

© 2020 Elsevier B.V. All rights reserved. CC BY-NC-ND (doi:10.1016/j.chroma.2020.461540)

Related URLs:
Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page