Filter Fluorometer Calibration Without the Fluorometer

We recently described a lightweight, low-power, waterproof filter fluorometer using a 180 & DEG; backscatter geometry for chlorophyll-a (chl-a) detection. Before it was constructed it was modeled to ensure it would have satisfactory performance. This manuscript repeats the modeling process that allows the calibration slope and detection limit for a fluorescent analyte in water to be estimated from system component performance and conventional spectrofluorometry alone. These values are validated by comparison to the experimental result of calibration from the completed instrument. Our model yields a calibration slope of 8.22 mV-L/& mu;g for dissolved chl-a, consistent with the experimentally measured slope of 8.21 mV-L/& mu;g. The detection limit modeled from this slope and an estimate of the baseline noise of the instrument was 0.15 & mu;g/L chl-a, while the measured detection limit using real blank samples was 0.18 & mu;g/L, in 0.1 s differential measurements.

Automated summary

We have developed a lightweight, low-power, waterproof filter fluorometer for chlorophyll-a detection. Through modeling and calibration, we determined the calibration slope and detection limit for dissolved chl-a in water. The experimental results validate our model, showing good agreement with the estimated values. The achieved detection limit is suitable for practical applications.