Figure 1
Figure 2
Figure 3
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 | 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 | Limit of quantification LOQ = 3.3 x LOD | 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 |