Table 3: Robustness of potentiometric method for GEMI determination.

Parameter Value Recovery % ± RSD*
Standard conditions 99.1 ± 0.44
pH 2.5 98.5 ± 0.39
3.5 99.1 ± 0.45
Temperature (℃) 30 98.3 ± 0.29
40 96.2 ± 0.63
Volume of buffer (ml) 2 99.3 ± 0.93
8 98.7 ± 0.66
Reaction time (sec) 2 96.3 ± 0.74
10 98.6 ± 0.48

(*values are mean of 3 determinations); RSD = (SD /mean*100).