Abstract
Aportable, 12 Vbattery-powered,automated spectrophotometric field monitor has been developed that permits the continuous long-term recording of the total ammonia concentration in the surrounding aquatic environment. The flow-injection (FI)-based monitor incorporates a gas diffusion unit and an acceptor stream containing an acid-base indicator. The detection system utilizes a red solid-state light-emitting diode source and photodiode detector. Remote control and data processing are achieved by an inhouse-designed microcomputer system. The instrumentation was fully evaluated in the laboratory and was shown to operate unattended for periods of up to 1 week (analyzing every hour) before battery charging and reagent replacement were required. The precision and accuracy of the chemical monitor was examined by continuously analyzing a sample of a known ammonia concentration (80.0 mg L-1 NH3-N) at 60 minute intervals over a 7 day period (n = 170). The calculated mean concentration was 79.0 mg L-1 (using 50 and 150 mg L-1 standards) with an RSD of 5.2%. The detection limit (3σ) was determined as 2.5 mg L-1. The feasibility of using the system in situ was demonstrated by a 2 week field trial in which the automated field monitor was successfully deployed at a landfill leachate lagoon. Data from the trial are presented, and the potential applications of the system in environmental management are discussed. © 1997 John Wiley & Sons, Inc.
Original language | English |
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Pages (from-to) | 175-183 |
Number of pages | 0 |
Journal | Laboratory Robotics and Automation |
Volume | 9 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Jan 1997 |