Thermo Fisher Scientific Ion Selective Electrodes Silver - Manual (Page 25)

Instruction Manual Silver/Silver Sulfide Electrode
25
Low Slope or standards contaminated prepare fresh standards
No Slope or incorrectly made
ISA not used use recommended ISA
standard used as ISA use ISA
electrode exposed check section entitled
to complexing agents
Complexation
air bubble on membrane remove bubble by
re-dipping probe
"Incorrect Answer"
incorrect scaling of plot millivolts on the linear
(but calibration semi-log paper axis. On curve is good)
the log axis, be sure that
concentration numbers
within each decade are
increasing with increasing
concentration
incorrect sign be sure to note sign of
millivolt number correctly
incorrect standards prepare fresh standards
wrong units used apply correct conversion
factor:
1.0X10
-3
M= 32.1 ppm S
-2
= 2.0X10
-3
N (S
-2
);
= 108 ppm Ag
+1
complexing agents check section entitled
in sample
Complexation