. 2020 Dec 12;9(12):1854. doi: 10.3390/foods9121854

Table 1.

Textural properties and functionalization degree of the prepared SBA-15 silicas compared with a commercial sorbent. Recovery percentages for atropine and scopolamine in standard solution using synthetized and commercial materials as strong cation-exchange solid-phase extraction (SCX-SPE) sorbent.

Material	S_BET ^a (m²/g)	Pore Volume ^b (cm³/g)	Pore Size ^c (Å)	L₀ ^d (mmol S/g)	SO₃⁻ Groups ^e (mmol/g)	Recovery (% ± SD) ^f
Material	S_BET ^a (m²/g)	Pore Volume ^b (cm³/g)	Pore Size ^c (Å)	L₀ ^d (mmol S/g)	SO₃⁻ Groups ^e (mmol/g)	Atropine	Scopolamine
SBA-15	780	0.8	56	-	-	-	-
L-SBA-15-SO₃⁻	587	0.7	55	0.5	0.3	38 ± 30	51 ± 13
M-SBA-15-SO₃⁻	460	0.6	49	0.9	0.5	90 ± 8	91 ± 9
H-SBA-15-SO₃⁻-	350	0.4	36	1.7	0.6	95 ± 0	104 ± 12
MFE-PAK^® SCX	398	0.6	61	0.8	0.3	91 ± 2	91 ± 2

^a S_BET: Specific surface area estimated by Brunauer-Emmett-Teller method. ^b Pore volume: Total pore volume measured at relative pressure 0.97. ^c Pore size: Diameter of pore estimated by Barret-Joyner-Halenda model applied in the desorption branch. ^d L₀: Degree of functionalization calculated through the sulfur percentage determined by elemental analysis. ^e SO₃⁻ groups: estimated by titration. ^f SPE experimental conditions—Sorbent amount: 50 mg. Conditioning: 2 mL of MeOH and 2 mL of 0.025 M phosphate buffer pH 4.8. Loading: 4 mL of 0.5 mg/L TAs standard solution, dissolved in MeOH/0.025 M phosphate buffer pH 4.8 (50:50, v/v). Washing: 2 mL of 0.025 M phosphate buffer pH 4.8. Elution: 3 × 3 mL of MeOH + 10% ammonia solution pH 11.8.