Column chromatographic methods, for

Mlcrochromatographlc Methods During the past two years rapid. Inexpensive, miniaturized column chromatographic methods for the separation of hemoglobins have been developed These methods are designed for the qualitative detection and quantitative determination of hemoglobins In normal and abnormal conditions and cover the quantitation of Hb-A2 the detection of Hb-S, Hb-C other abnormal Hbs differentiation of various conditions In adults and the detection of hemoglobinopathies especially sickle cell anemia at birth (27, 28, 29, 30) ... 

Gorcharova and Khomenko [127] have described a column chromatographic method for the determination of acetic, propionic, and butyric acids in seawater, and thin-layer chromatographic methods for determining lactic, aconitic, malonic, oxalic, tartaric, citric, and malic acids. The pH of the sample is adjusted to 8 - 9 with sodium hydroxide solution. It is then evaporated almost... 

Karajannis, S., Ortner, H. M., Spitzy, H. Column-chromatographic method for removal of the molybdenum matrix in determination of alkali and alkaline-earth metals in molybdenum and its compounds. Talanta 19, 903 (1972)... 

Table 6.4 Examples of column chromatographic methods for separation of (phospho)lipid fractions... 

Wallace, D, Henry, D. Pongar, K. Zimmerman, D. (1987). Evaluation of Some Open Column Chromatographic Methods for Separation of Bitumen Components. Fuel, Vol.66, No.l, pp. 44-50... 

More specific methods involve chromatographic separation of the retinoids and carotenoids followed by an appropriate detection method. This subject has been reviewed (57). Typically, hplc techniques are used and are coupled with detection by uv. For the retinoids, fluorescent detection is possible and picogram quantities of retinol in plasma have been measured (58—62). These techniques are particularly powerful for the separation of isomers. Owing to the thermal lability of these compounds, gc methods have also been used but to a lesser extent. Recently, the utiUty of cool-on-column injection methods for these materials has been demonstrated (63). 

TNMe on alkaline hydrolysis. In an ion exclusion-partition chromatographic method for the sepn of acids, TNMe emerged from the column betw citric and itaconic acids (Ref 36) Impact Sensitivity. On the BRL machine (1kg wt), using a noisemeter to detect explns, the 50% expin height was found to be 218cm. A 50/50 mixt with kerosene had a 50% expln height of 130cm (Ref 21)... 

Schleyer, E., Reinhardt, J., Unterhalt, M., Hiddemann, W. (1995). Highly sensitive coupled-column high-performance liquid chromatographic method for the separation and quantitation of the diastereomers of leucovorin and 5-methyltetrahydrofolate in serum and urine. J. Chromatogr. B 669, 319-330. 

Tab. 2.3. Liquid-liquid chromatographic methods for the measurement of log D. Selection of column and mobile phase.

Szathmary and Luhmann [50] described a sensitive and automated gas chromatographic method for the determination of miconazole in plasma samples. Plasma was mixed with internal standard l-[2,4-dichloro-2-(2,3,4-trichlorobenzyloxy) phenethyl]imidazole and 0.1 M sodium hydroxide and extracted with heptane-isoamyl alcohol (197 3) and the drug was back-extracted with 0.05 M sulfuric acid. The aqueous phase was adjusted to pH 10 and extracted with an identical organic phase, which was evaporated to dryness. The residue was dissolved in isopropanol and subjected to gas chromatography on a column (12 m x 0.2 mm) of OV-1 (0.1 pm) at 265 °C, with nitrogen phosphorous detection. Recovery of miconazole was 85% and the calibration graph was rectilinear for 0.25 250 ng/mL. 

Kublin and Kaniewska [52] used a gas chromatographic method for the determination of miconazole and other imidazole antimycotic substances. The conditions have been established for the quantitative determination of miconazole and the other drugs, which are present in pharmaceuticals such as ointments and creams. The column, packed with UCW-98 on Chromosorb WAW, and flame-ionization detector were used. The statistical data indicate satisfactory precision of the method, both in the determination of imidazole derivatives in substances and in preparation. 

Guo et al. [53] developed a gas chromatographic method for the analysis of miconazole nitrate in creams and injections. The conditions were flame ionization detector, stationary phase of 5% SE 30 support of Chromosorb W (AS-DMCS, 80—100 mesh) packed column 3 m x 3 mm column temperature 275 °C injection temperature 290 °C and diisooctyl sebacate and internal standard. The average recoveries for creams and injections were 97.7 and 101.4%, respectively. The relative standard deviations were 2.2 and 1.3%, respectively. 

Gagliardi et al. [72] developed a simple high performance liquid chromatographic method for the determination of miconazole and other antimycotics in cosmetic antidandruff formulations. This high performance liquid chromatographic method was carried out on a Discovery RP Amide Ci6 column and spectrophotometric detection was performed at 220 nm. The initial mobile phase was a mixture of acetonitrile and aqueous 0.001 M sodium perchlorate (pH 3) in the ratio of 15 85 (v/ v) then a linear gradient less than 46% acetonitrile in 70 min, and less than 50% in 80 min. The extraction procedure was validated by analyzing samples of shampoo... 

Parkhurst et al. [79] described a high performance liquid chromatographic method for the simultaneous determination of primaquine and its metabolites from plasma and urine samples, utilizing acetonitrile deproteinization, and direct injection onto a cyano column. Levels of 100 ng/mL per 20 pL injection could be quantitated. Preliminary pharmacokinetic analysis is reported for two human subjects after oral doses of 60 90 mg primaquine diphosphate. Two apparent plasma metabolites and two possible urinary metabolites are also reported. 

Katori et al [84] used a high performance liquid chromatographic method for the determination of primaquine phosphate tablets. Chromatography on a TSK Gel-4 (octadecylsilanized) column was used to determine the active ingredient in tablets and injections for treating tropical diseases. The mobile phase used is 26% acetonitrile in 0.05-M pH-3 phosphate buffer and the drug was detected at 260 nm. The peak area and peak height reproducibilities were <1.69%, and results compared well with those of other methods. 

Sidhu et al [86] developed a reliable and simple high performance liquid chromatographic method for the routine analysis of pharmaceutical dosage forms using a Cig Bondapak reversed-phase column with a binary solvent system consisting of... 

Rao et al. [87] developed a high performance liquid chromatographic method for the determination of primaquine phosphate in pharmaceutical dosage form. A /(-Bondapak NH2 column with chloroform-methanol (60 40) as eluent was selected with sulfalene as internal standard. The method was convenient with recovery of approximately 100% for primaquine. 

Dean et al. [93] used a high performance liquid chromatographic method for the simultaneous determination of primaquine and carboxyprimaquine in plasma with electrochemical detection. After the addition of the internal standard, plasma was deproteinized by the addition of acetonitrile. Nitrogen-dried supernatants, resuspended in mobile phase were analyzed on a C8 reversed-phase column. Limits of detection for primaquine and carboxyprimaquine were 2 and 5 ng/mL with quantitation limits of 5 and 20 ng/mL, respectively. The assay sensitivity and specificity are sufficient to permit quantitation of the drug in plasma for pharmacokinetics following low dose (30 mg, base) oral administration of primaquine, typically used in the treatment of malaria and P. carinii pneumonia. 

Lee et al. [30] described a micellar electrokinetic capillary chromatographic method for the determination of some antiepileptics including valproic acid. They used a fused silica capillary column (72 cm x 50 pm) and SDS as the micellar phase and multiwavelength UV detection. Reaction conditions, such as pH and concentration of running buffer were optimized. Solutes were identified by characterizing the sample peak in terms of retention time and absorption spectra. Recoveries were 93-105%. 

Tsuji and Goetz24 developed a quantitative high performance liquid chromatographic method for separating and measuring erythromycins A, B, and C, their epimers and degradation products. This method uses a /iBondapak Ci 8 reverse column with acetonitrile-methanol-O.2m ammonium acetate-water (45 10 10 25) as solvent. The pH and composition of the mobile phase may be adjusted to optimize resolution and elution volume. The authors utilized the procedure on USP reference standard and report a relative standard deviation of 0.64%. 

A high-performance liquid chromatographic method for nalidixic acid on a strong anion-exchange resin column has been reported, using a mobile phase of 0.01 M sodium tetraborate at pH 9.2 and 0.003 M sodium sulfate. The relative retention time for nalidixic acid in the system reported by Sondach and Koch was 0.86 with sulfanilic acid as the standard at... 

Initially, progress in this area was hampered by the lack of suitable analytical methods for chiral hydrocarbons. Early studies relied on optical rotation to determine enantiomeric excess (ee) values, but with the development of chiral gas chromatography (GC) and high-performance liquid chromatography (HPLC) columns, chromatographic methods have become more common. 

Reeves and Woodham [83] have described a gas chromatographic method for the determination of Methomyl (S-methyl-N-(methyl carbamoyl)oxy thioacetimidate) insecticide in sediments. The residues were extracted with dichloromethane, and the extracts were purified on a column of Florisil. The purified and concentrated extracts were then examined by gas chromatography. The limits of detection were 0.05mg kg-1 and the recoveries were 91%. 

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