Robotic arms Atomic absorption spectrometers 2 Atomization 2 Chemical modification 2 Closed loop control systems 2 Concentration (process) 2 Control engineering 2 Control problem 2 Control theory 2 Drinking water 2 Electrothermal atomic absorption spectrometry 2 Feedback 2 Flow injection 2 Flow injection (FI) 2 Full state vector 2 Negative ions 2 Neural networks 2 Nonlinear control systems 2 Nonlinear observer 2 Permanent modifiers 2 Potable water 2 Resins 2 Selenium compounds 2 Selenium speciation 2 Separation 2 State estimation 2 State variable estimation 2 Tap water 2 Trace analysis 2 Trajectory tracking 2