Dirui CS-T240 - The Measurement of Internal Liquid Concentration; Test Method; Working Curve Preparation

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T: absolute temperature (t ℃ +273.15) (K)
F: Faraday constant (9.6485309 × 104 C × mol-1)
ai
: Ion (i) activity
f: activity coefficient
Ci: concentration
n: a given ion (i) the charge number (Cation is positive, anion is
negative)
8.6.3 Test method
Working curve preparation, the internal standard solution concentration
measurement, concentration calculation, and result modification are explained
as follow.
8.6.3.1 Working curve preparation
Measure low concentration slope of liquid (S1) and high concentration slope
liquid (S2), and determine slope value (sensitivity) of K, Na, Cl the
electrode.
( ) ()
()
log
()
EH EL
SL
CH
CL
−
=
…………………………………………………… (3)
SL: slope value (slope)
E (H): the potential of high concentration slope solution
E (L): the potential of low concentration slope solution
C (H): high concentration of the concentration slope solution (input value)
C (L): low concentration of the concentration slope solution (input value)
8.6.3.2 The measurement of internal liquid concentration
( ) ()
( ) ( ) 10
EIS EL
SL
CIS CL
−
= ×
…………………………………………… (4)