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1

Micellar electrokinetic chromatography with bile salts for separation of flavanone diastereomers

Kowalczyk M., Asztemborska M.

Camera Separatoria

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2016

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Vol. 8, No. 1

45--54

EN

Sodium cholate and sodium deoxycholate were applied in the micellar electrokinetic chromatography technique as separating agents for the diastereomers of flavanone glycosides. The effects of the organic solvent buffer modifier, bile salt type and concentration were evaluated for enhancing distereomer separation. The critical micelle concentration of sodium cholate and sodium deoxycholate in the applied running buffer was determined. The bi nding constants of flavanone glycosides to bile salts micelle were estimated. The elaborated analytical method was used to analyse the flavanone fraction of bitter orange (Citrus aurantium) and grapefruit (Citrus paradisi) juice.

PL

Cholan sodu i deoksycholan sodu zostały zastosowane w technice micelarnej elektrokinetycznej chromatografii cieczowej jako czynnik rozdzielający diastereomery glikozydów flawanonów. Oceniono wpływ rozpuszczalnika organicznego jako modyfikatora buforu, typu soli żółciowej oraz jej stężenia na wzmocnienie rozdzielenia diastereomerów. Wyznaczono krytyczne stężenie micelarne cholanu sodu i deoksycholanu sodu w zastosowanym buforze rozdzielającym. Oszacowano stałe trwałości glikozydów flawanonów z micelami soli żółciowych. Opracowana metoda została wykorzystana do analizy frakcji flawanonowej w soku gorzkiej pomarańczy (Citrus aurantium) i grejfruta (Citrus paradise).

2

Stress degradation studies on aliskiren and the development of a sensitive stability-indicating MEKC method

Sangoi M. S., Wrasse-Sangoi M., Hurtado F. K., Rolim C. M. B.

Acta Chromatographica

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2013

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Vol. 25, no. 4

711--724

EN

A sensitive, fast, and stability-indicating micellar electrokinetic chromatographic (MEKC) method was developed and validated for the analysis of aliskiren (ALI) in tablets using nimesulide as internal standard (IS). Optimal conditions for the separation of ALI and its degradation products were investigated. The method employed 60 mM Tris buffer and 50 mM anionic detergent sodium dodecyl sulfate (SDS) solution at pH 9.8. MEKC method was performed on a fused-silica capillary (50 μm id; effective length, 40 cm). The capillary temperature was maintained at 35°C, and the applied voltage was 30 kV, with detection by photodiode array (PDA) detector set at 204 nm. The method was validated in accordance with the International Conference on Harmonisation (ICH) requirements. The stability-indicating capability of the method was established by enforced degradation studies combined with peak purity assessment using PDA detection. The method was linear over the concentration range of 5–150 μg mL -1 (r2 = 0.9996) of ALI. Intraday and interday precision and accuracy evaluated by relative standard deviation, respectively, were lower than 2%. The limit of detection was 1.31 μg mL -1. The method proved to be robust by a one-variable-at-a-time evaluation. The proposed MEKC method was successfully applied for the quantitative analysis of ALI in tablets to support the quality control.

3

Micellar electrokinetic chromatographic separation and quantitative analysis of thorium, uranium, gold, and mercury from environmental ore samples

Mallah A, Memon S. Q., Khuhawar M.Y., Solangi A. R., Bhanger M. I.

Acta Chromatographica

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2011

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Vol. 23, no. 1

69--80

EN

A rapid and reliable analytical procedure has been developed for the separation and analysis of dioxouranium, thorium, gold, and mercury by micellar electrokinetic chromatography (MEKC) using bis(acetylacetone)ethylenediamine (H2AA2en) as complexing reagent. Under the optimized conditions (64 mM borate buffer containing 12.25 mM SDS and 13% acetonitrile, pH 8.0, 25 kV, 311 nm as detection wavelength) the ions were separated within 5.0 min. Linear dynamic ranges were 1–5, 8–42, 10–50, and 2–40 μg mL -1, respectively, for gold, mercury, thorium, and uranium and the respective detection limits were 0.66, 3.33, 1.6, and 3.3 μg mL -1. The applicability of method has been evaluated by application to uranium and thorium from ore samples.

4

Micellar electrokinetic chromatographic separation and analysis of thorium, uranium, gold, and mercury in environmental ore samples

Mallah A, Memon S. Q., Solangi A. R., Khuhawar M. Y., Bhanger M. I.

Acta Chromatographica

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2010

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Vol. 22, no. 3

405--417

EN

A fast and reliable analytical procedure has been developed for separation and analysis of dioxouranium, thorium, gold, and mercury by micellar electrokinetic chromatography (MEKC) using bis(acetylacetone)ethylenediamine (H 2 AA 2 en) as complexing reagent. Under the optimized conditions (64 mM borate buffer containing 12.25 mM SDS and 13% acetonitrile, pH 7.99; 25 kV; detection wavelength 311 nm), other ions present were separated within 5 min. Linear dynamic ranges 1–5, 8–42, 10–50, and 2–40 μg mL -1 and detection limits 0.66, 3.33, 1.6, and 3.3 μg mL -1, respectively, were achieved for gold, mercury, thorium, and uranium. The applicability of method was evaluated by analysis of uranium and thorium in ore samples.