Development of an extraction procedure and analysis of electrostatically stabilized silanates from aqueous solutions

Figure 1

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Figure 4

Optimum conditions for isotachophoretic separation of a mixture 1-(N-morpholiniomethyl)spirobi(1-sila-2,5-dioxacyclopentan-3-on)at (72), 1-(N-morpholiniomethyl)spirobi(1-sila-2,5-dioxa-4-methylcyclopentan-3-on)at (73), 1-(N-morpholiniomethyl)spirobi(1-sila-2,5-dioxa-4-(i-propyl)cyclopentan-3-on)at (79)

Considered parameters
Stage	Time (s)	Intensity (μA)	Comp (10 mV)	Conductometric detector
1	50	80	0
2	70	120	50
3	20	90	0	X
4	250	50	50
5	325	120	0	X

Characteristic of the applied analytical method

Analyte	Linearity determination coefficient above 0.9987 (μg l−1)	Coefficient of variation n = 6, the samples were analyzed twice (%)	Limit of detection calculated from the limit of identification and coefficients of the calibration curve (LOD) (μg l−1)	Limit of quantification LOQ = 3.3 x LOD (LOQ) (μg l−1)	Recovery the sample was enriched with 4 ml of a solution containing 2 μg fil-1 of the examined ion, n = 6 (%)
(72)	3.1–50.4	3.0–4.2	2.2	7.3	91 ± 5
(73)	2.8–49.6	3.2–4.5	2.1	6.9	92 ± 3
(79)	2.9–51.3	2.8–4.1	2.3	7.6	92 ± 4

Mean recovery values [1-(N-morpholiniomethyl)spirobi(1-sila-2,5-dioxacyclopentan-3-on)at (72), 1-(N-morpho liniomethyl)spirobi(1-sila-2,5-dioxa-4-methylcyclopentan-3-on)at (73), 1-(N-morpholiniomethyl)spirobi(1-sila-2,5-dioxa-4-(i-propyl)cyclopentan-3-on)at (79)] obtained on the columns used in the study (n = 5)

Type of extraction column	Mean recovery values and SD (%)
	(72)	(73)	(79)
RP Si–C18	85.3 ± 4.2	84.7 ± 3.9	85.1 ± 3.5
RP Si–C8	82.2 ± 4.3	82.9 ± 4.9	83.7 ± 4.6
RP Si–FP	89.3 ± 3.9	91.3 ± 3.6	93.9 ± 4.1

Common parameters of optimal (72), (73) and (79) separation and determination by the isotachophoresis method

Parameters of the method
UV filter (nm)	200
High Voltage Limit (kV)	12
Sample rate (smp s−1)	50
Polarity	+ cations