Development of hardware and software for on-line sample preparation using sequential-injection analysis

This work describes the software and hardware developed for implementation of on-line microwave-assisted sample digestion in an automated sequential-injection analysis (SIA) system. The system was completely developed with conventional equipment available in analytical laboratories. The software and hardware allows for the acquisition and manipulation of analytical signals and also for the synchronization of the actuation of each component. The assembled system is composed of a mixing valve, three solenoid valves, a commercial microwave oven, a peristaltic pump, and an ultrasonic bath. Additionally, it is possible to program 60 different events that can be controlled by the operator according to the requirement of analysis. The operator only needs to inject the samples, and the other steps are carried out by the automated SIA system. This system was applied for direct determination of Fe in white wines and presented a sampling frequency of 10 h−1. The limit of detection was 0.6 mg L−1, and an addition-recovery experiment led to recoveries in the 98–101% range. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:246–252, 2000