Table 1.

Physicochemical and chromatographic parameters of TLC silica gel 60 RP-18 F₂₅₄S and HPTLC silica gel 60 RP-18 WF₂₅₄S glass plates listed in Certificates of Analysis provided by Merck to each plates batch

Parameter	Specification	Batch values
A: TLC layer (RP-18 F254S)
Specific surface area (according to BET; 5-Pt. measurement) [m2 g−1]	480–540	511
Pore volume (N2 isotherm) [mL g−1]	0.74–0.84	0.78
d 50 (laser diffraction, size distribution) [μm]	9.5–11.5	11.4
Layer thickness [μm]	200–270	210
Deviation of layer thickness per plate	≤35	10
Chromatography test (cholesterol elution) [hRF]	31–43	40
B: HPTLC layer (RP-18 WF254S)
Specific surface area (according to BET; 5-Pt. measurement) [m2 g−1]	480–540	521
Pore volume (N2 isotherm) [mL g−1]	0.74–0.84	0.8
d 50 (laser diffraction, size distribution) [μm]	5–7	6
Layer thickness [μm]	150–200	170
Deviation of layer thickness per plate	≤35	15
Chromatography test (cholesterol elution) [hRF]	54–66	58