Page 12 - Performance Verification Statement for the Chelsea UV Aquatracka Fluorometer

Ref. No. [UMCES]CBL 2013-014
ACT VS12-01
concentration and estimated EEMQSE (Quinine Sulfate equivalent) fluorescence intensity for each
challenge compound. As expected by factory design, the voltage output response to increasing
concentration (panel A) was logarithmic. Baseline signal was high (2200 to 2800 mV in
deionized water) presumably to improve detection at low analyte concentrations. The instrument
response to increasing concentration was significantly less for those compounds (NDSA and
BB3) with fluorescence maxima outside the optical windows of the instruments filter set and
hence much lower EMMQSE intensities (panel B). Ancillary water quality conditions for
turbidity and CDOM are presented for each challenge compound at each of the concentrations
tested. In general the challenge compounds, except for BB3, had little effect on turbidity levels
and the instrument response reflected the fluorescence properties of the challenge compound.
BB3 additions increased measured turbidity but the UV-CDOM instrument did not detect the dye
additions although some signal quenching was evident above 100 ppb additions.
Spectroscopically derived CDOM levels were compound specific and reached asymptotes above
10 ppb additions, well below the instruments’ logarithmic response capacity (ca 500 ppb for QS
and #2 diesel fuel oil).
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