Table 1 Metrological parameters (regression and validation data) of the techniques employed for distigmine determination.

Parameter	ISE	UV	HPLC	TLC
Accuracy (mean ± S.D.)^a	100.51 ± 0.531	100.53 ± 0.482	100.19 ± 1.344	100.62 ± 0.791
Specificity	100.49 ± 1.486	100.78 ± 0.662	99.93 ± 1.424	100.42 ± 1.686
Repeatability^b	0.671	0.971	1.197	0.783
Intermediate precision^c	0.771	1.087	1.234	0.962
Slope^d	27.51	0.0196	0.0619	0.2231
Intercept	309.6	0.0095	0.06	0.0101
Correlation coefficient	0.9993	0.9999	0.9998	0.9998
Range	0.15 μM–10.0 mM	17.35–104.10 μM	6.94–55.52 μM	2–12 μg/spot
LOD^e	0.078 μM	5.22 μM	1.65 μM	0.62 μg/spot
LOQ^f	0.099 μM	15.82 μM	5.01 μM	1.88 μg/spot

^aThe accuracy (n = 3), average of three concentrations (1.0 × 10^–3, 1.0 × 10^–4 and 1.0 × 10^–5 M for ISE), (15.0, 35.0 and 55.0 µg/mL for UV), (10.0, 22.0 and 30.0 µg/mL for HPLC) and (5.0, 7.0 and 9.0 µg/spot for TLC).
^bThe intra-day (n = 3), RSD% of concentrations (5.0 × 10^–3, 6.0 × 10^–4 and 8.0 × 10^–5 M for ISE), (20.0, 30.0 and 50.0 µg/mL for UV), (8.0, 16.0 and 24.0 µg/mL for HPLC) and (2.0, 6.0 and 10.0 µg/spot for TLC).
^cThe inter-day (n = 3), RSD% of concentrations (5.0 × 10^–3, 6.0 × 10^–4 and 8.0 × 10^–5 M for ISE), (20.0, 30.0 and 50.0 µg/mL for UV), (8.0, 16.0 and 24.0 µg/mL for HPLC) and (2.0, 6.0 and 10.0 µg/spot for TLC).
^dAverage of three determinations.
^eLimit of detection for ISE is measured according to IUPAC by interception of the extrapolated arms of nonresponsive and Nernstian segments of the calibration plot of Figure S7. While for other methods, LOD is calculated according to ICH from the standard deviation (σ) of the regression residuals and the slope of the calibration curve (S) according to the following equations: LOD = 3.3(σ/S).
^fLOQ is calculated according to ICH from the standard deviation (σ) of the regression residuals and the slope of the calibration curve (S) according to the following equations: LOQ = 10(σ/S).

Search