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.
The Robertson Trust Laboratory for Electronic Sterilisation Technologies, University of Strathclyde, Royal College, 204 George Street, Glasgow G1 1XW, UK.
T
T
Wang
S J
SJ
Macgregor
J G
JG
Anderson
G A
GA
Woolsey
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