Pulsed ultra-violet inactivation spectrum of Escherichia coli.
Inactivation of Escherichia coli is examined using ultra-violet (UV) radiation from a pulsed xenon flashlamp. The light from the discharge has a broadband emission spectrum extending from the UV to the infrared region with a rich UV content. The flashlamp provides high-energy UV output using a small number of short-duration pulses (30 micros). The flashlamp is used with a monochromator to investigate the wavelength sensitivity of E. coli to inactivation by the pulsed UV light. Using 8 nm wide pulses of UV radiation, the most efficient inactivation is found to occur at around 270 nm and no inactivation is observed above 300 nm. A pyroelectric detector allows the energy dose to be determined at each wavelength, and a peak value for E. coli population reduction of 0.43 log per mJ/cm(2) is measured at 270 nm. The results are compared with the published data available for continuous UV light sources.
Wang
T
T
The Robertson Trust Laboratory for Electronic Sterilisation Technologies, University of Strathclyde, Royal College, 204 George Street, Glasgow G1 1XW, UK.
Macgregor
S J
SJ
Anderson
J G
JG
Woolsey
G A
GA
D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods*; D004926:Escherichia coli / Q000302:isolation & purification / Q000528:radiation effects*; D013997:Time Factors; D014466:Ultraviolet Rays; D018508:Water Purification / Q000379:methods*; D014978:Xenon
D014978:Xenon