Thermo Fisher Scientific Ion Selective Electrodes Ammonia - Manual (Page 3)

TABLE OF CONTENTS
TABLE OF CONTENTS .................................................................................................................................1
GENERAL INSTRUCTIONS .........................................................................................................................1
Introduction.................................................................................................................................................1
Required Equipment ...................................................................................................................................1
Required Solutions......................................................................................................................................1
GENERAL PREPARATION ..........................................................................................................................2
Electrode Preparation..................................................................................................................................2
Checking Membrane...................................................................................................................................2
Changing Membrane (see Figure 4) ...........................................................................................................2
Connecting the Electrode to the Meter .......................................................................................................3
Electrode Slope Check (with pH/mV meter) ..............................................................................................3
Electrode Slope Check (with ion meter) .....................................................................................................3
MEASUREMENT ............................................................................................................................................4
Measuring Hints..........................................................................................................................................4
Sample Storage ...........................................................................................................................................4
Sample Requirements .................................................................................................................................4
Units of Measurement.................................................................................................................................5
MEASUREMENT PROCEDURE ..................................................................................................................5
Direct Measurement....................................................................................................................................5
Direct Measurement of Ammonia (using a pH/mV meter) ........................................................................5
Direct Measurement of Ammonia (using an ion meter) .............................................................................6
Low Level Ammonia Determination (using a pH/mV meter) ....................................................................7
Ammonia Measurements in Membrane Wetting Solutions ........................................................................8
ELECTRODE CHARACTERISTICS ...........................................................................................................9
Reproducibility ...........................................................................................................................................9
Interference .................................................................................................................................................9
Effect of Dissolved Species ........................................................................................................................9
Complexation............................................................................................................................................10
Temperature Influences ............................................................................................................................10
Electrode Response...................................................................................................................................10
Limits of Detection ...................................................................................................................................11
pH Effects .................................................................................................................................................11
Electrode Life ...........................................................................................................................................11
Electrode Storage......................................................................................................................................11
ELECTRODE THEORY...............................................................................................................................11
Electrode Operation ..................................................................................................................................11
Ammonia Chemistry.................................................................................................................................12
TROUBLESHOOTING GUIDE ...................................................................................................................13
Meter.........................................................................................................................................................13
Glassware..................................................................................................................................................14
Electrodes .................................................................................................................................................14
Standards...................................................................................................................................................14
Sample ......................................................................................................................................................14
Technique .................................................................................................................................................15
TROUBLESHOOTING HINTS....................................................................................................................16
Checking the Electrode Inner Body..........................................................................................................18