YSI 2900 - 8.2.14 Simultaneous Ammonium and Potassium

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8.2.14 Simultaneous Ammonium and Potassium
This is a direct reading of Ammonium and Potassium in solution at the ISE.
A Probe
B Probe
Chemistry
Name
Ammonium Potassium
System
Buffer
YSI 2970
Calibrator
Std
YSI 2972 YSI 2971
Linearity
Std
YSI 7173 and YSI 7179
ISE Probe
YSI 2974 YSI 2975
Reference
Probe
YSI 2976
Sample
Size
25 µL
Detection
Range
10–500
mg/L
20–1000
mg/L
Calibration
Point
500 mg/L
1000
mg/L
Check
Point
100 mg/L 200 mg/L
End Point
30 sec
Precision
(CV,n=10)
5% or 10
mg/L,
whichever
is greater
5% or 20
mg/L,
whichever
is greater
Linearity
±5%
Typical
Working
Life
90 days
Note: See Appendix B – Concentration
Unit Conversion if concentration unit
conversion is required.
Special Considerations:
• Sodium may be an interferent to the measurement of
ammonium with some samples. The interference is
relatively small on a weight/weight basis (<1%). The
2900 Series does not automatically compensate for the
presence of sodium. In order to check the potential
sodium interference, YSI provides 7173 NaCl Check
Solution (4 g/L Na
+
). Presented as a sample, the effect
of sodium on the ammonium sensor (and to a lesser
extent on the potassium sensor) can be determined. If
you determine this sodium presence is a significant
factor in your measurement, you may use the result of
the 7173 measurement to correct ammonium readings.