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HPLC determination of enantiomeric thiazolidine-2-carboxylic acid on chiral stationary phase with pre-column derivatization

Zhang Y., Peng Q., Zeng H., Yao S, Zhang Y., Song H.

Acta Chromatographica

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2013

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Vol. 25, no. 2

287--296

EN

A new high-performance liquid chromatography (HPLC) method has been developed and validated for determination of enantiomeric purity of thiazolidine-2-carboxylic acid within a short run time of less than 10 min. The method was based on pre-column derivatization of thiazolidine-2-carboxylic acid with aniline, and complete separation of enantiomers has been achieved on a Chiralcel OD-H analytical column (250 × 4.6 mm) using n-hexane-isopropanol (85:15 v/v) as mobile phase at a flow rate of 1.0 mL min-1 under UV and optical rotation (OR) detection. Detection wavelength was set at 254 nm. Then the effects of mobile phase and temperature on enantioselectivity were further evaluated. The method was validated with respect to precision, accuracy, linearity, limit of detection (LOD), limit of quantification (LOQ), and robustness. The recoveries were between 98.5 and 101.3% with percentage relative standard deviation less than 1.16%. The LOD and LOQ for the aniline derivatives of (+)-thiazolidine-2-carboxylic acid were 4.9 and 16.4 μg mL-1 and for the aniline derivatives (−)-thiazolidine-2-carboxylic acid were 5.1 and 17.2 μg mL-1, respectively.

2

Highly sensitive liquid chromatographic analysis of artemisinin and its derivatives after pre-column derivatization with 4-carboxyl-2,6-dinitrobenzene diazonium ion

Adegoke O. A, Xiang L. L, Idowu O. S, Chen D.-Y

Acta Chromatographica

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2012

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Vol. 24, no. 3

445--462

EN

A highly sensitive and reproducible isocratic liquid chromatographic method has been developed for the analysis of artemisinin and its three commonly used derivatives (artesunate, dihydroartemisinin, and artemether). The method involves a precolumn derivatization reaction with 4-carboxyl-2,6-dinitrobenzene diazonium ion to produce azo adducts that are UV-active. The critical parameters for the derivatization such as temperature, reaction time, and reagent concentrations were studied and optimized. The chromatographic separations were carried out on a C-18 column with mobile phase consisting of acetonitrile-0.1% acetic acid (60:40) at a flow rate of 1 mL min−1. UV detection was set at 254 nm. Dynamic linear calibration range was obtained at concentrations of artemisinins ranging from 0.26 to 1.44 μg mL−1. The low limits of detections of artemisinin, artesunate, dihydroartemisinin, and artemether were found to be 0.091, 0.0125, 0.0489, and 0.0128 ng μL−1, respectively. The developed methods were precise (RSD <3%) and accurate (% error < 5%). The developed methods may find application in dosage form analysis and pharmacokinetic studies.

3

Determination of sulfite by ion pair chromatography using pre-column derivatization with iron(III)-1,10-phenanthroline complex

Janovskiene G., Paliulionyte V., Padarauskas A.

Chemia Analityczna

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2002

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Vol. 47, No. 6

847-854

EN

An ion-pair chromatographic (IP-HPLC) method was developed for the selective and sensitive determination of sulfite. The proposed method is based on the pre-column derivatiza-tion of sulfite with iron(III)-l,10-phenathroline complex (Fe(phen)(3+/(3) and direct photometric detection of Fe(phen)(2+)(3) formed. The optimized separations were carried out on a C(18) column using acetonitrile-water (60:40) mobile phase containing 50 mmol L(-1) NaClO4 and 5 mmol L(-1) acetate buffer (pH 5.0) and direct photometric detection at 510 nm. The optimal conditions for the derivatization reaction were established by varying pH, concentration of Fe(phen)(3+)/3 and reaction temperature. Valid calibration (r2 = 0.998) is demonstrated in the range 2 x 10(-6)-5 x 10(-4) mol L(-4) of sulfite. The detection limit (S/N = 3) was 5 x 10(-7) mol L(-1). The proposed system was applied to the determination of free sulfite in wines. The recovery tests established for wine samples were within the range 94-105%. The IP-HPLC results agree with those obtained by iodometric titration technique.

PL

Opracowano selektywną i czułą metodę oznaczania siarczynów przy pomocy chromatografii par jonowych (IP-HPLC). Proponowana metoda jest oparta na przedkolumnowej derywaty-zacji siarczynu przy użyciu kompleksu żelazo(III)-1, 10-fenantrolina Fe(phen)(+3/3 Utworzony jon Fe(phen)j+jest bezpośrednio mierzony fotometrycznie przy długości fali 510 nm. Optymalizację rozdziału przeprowadzono na kolumnie C(18) z fazą ruchomą acetonitryl-woda (60:40) z dodatkiem 50 mmol L(-1) NaClO(4) i 5 mmol L(-1) buforu octanowgo (pH 5,0). Optymalne warunki reakcji derywatyzacji ustalano zmieniając wartości pH, stężenie Fe(phen)(+3)/(3) oraz temperaturę. Liniową zależność kalibracyjną (r2 = 0,998) uzyskano w zakresie stężeń 2 x 10(-6) -5 x 10(-4) mol L(-1) siarczynów. Granica wykrywalności (S/N = 3).