A new filter that accurately mimics the solar UV-B spectrum using standard UV lamps: the photochemical properties, stabilization and use of the urate anion liquid filter.
The physiological effects unique to solar ultraviolet (UV)-B exposure (280-315 nm) are difficult to accurately replicate in the laboratory. This study evaluates the effectiveness of the sodium urate anion in a liquid filter that yields a spectrum nearly indistinguishable from the solar UV-B spectrum while filtering the emissions of widely used UV-B lamps. The photochemical properties and stability of this filter are examined and weighed against a typical spectrum of ground-level solar UV-B radiation. To test the effectiveness of this filter, light-saturated photosynthetic oxygen evolution rates were measured following exposure to UV-B filtered either by this urate filter or the widely used cellulose acetate (CA) filter. The ubiquitous marine Chlorophyte alga Dunaliella tertiolecta was tested under identical UV-B flux densities coupled with ecologically realistic fluxes of UV-A and visible radiation for 6 and 12 h exposures. These results indicate that the urate-filtered UV-B radiation yields minor photosynthetic inhibition when compared with exposures lacking in UV-B. This is in agreement with published experiments using solar radiation. In sharp contrast, radiation filtered by CA filters produced large inhibition of photosynthesis.
Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA.
Priya
P
Sampath-Wiley
Leland S
LS
Jahnke
D000975:Antioxidants / Q000737:chemistry; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D000460:Chlorophyta / Q000737:chemistry* / Q000254:growth & development / Q000528:radiation effects*; D005374:Filtration / Q000295:instrumentation*; D007202:Indicators and Reagents; D010084:Oxidation-Reduction; D010782:Photolysis; D010788:Photosynthesis / Q000528:radiation effects; D019810:Sodium Azide / Q000737:chemistry; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays; D014527:Uric Acid / Q000737:chemistry*
D000975:Antioxidants; D007202:Indicators and Reagents; D012996:Solutions; D014527:Uric Acid; C005062:acetylcellulose; D002482:Cellulose; D019810:Sodium Azide