CHED 267 |
| Chemiluminescence was used to determine bromide in saline wetland samples. 400µL Chloramine-T solution (0.1% in 0.5M acetate buffer, pH 4.7) converted the bromide in 900µL of sample to bromine. After two minutes, 1500µL luminol (1mM in 1.0M carbonate buffer, pH 10.5) was added producing chemiluminescence. After a one minute delay, a 200-800nm emission scan was obtained: the 415nm peak maximum was measured three minutes after adding luminol. Calibration sensitivity varied with salinity requiring the use of standard additions. A non-zero intercept of calibration curves required a 4.3ppm correction be applied to concentrations calculated from standard additions plots prior to accounting for sample dilution. The working range for the analysis was 5-40ppm bromide. Concentrations below 5ppm could not be determined because no appreciable signal was observed below that level. Samples obtained from bodies of water in the Redhead Ridge Unit of the Laguna Atascosa National Wildlife Refuge were analyzed. |
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Undergraduate Research Poster Session: Analytical Chemistry
11:00 AM-1:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster
Division of Chemical Education |