High performance liquid standard methods

Sternson et al. [58] used a high performance liquid chromatographic method for the analysis of miconazole in plasma. Miconazole was extracted from alkalinized plasma with n-heptane-isamyl alcohol (98.5 1.5) and separated by high performance performance liquid chromatography on p-Bondapak Ci8 with ultraviolet detection at 254 nm. The mobile phase was methanol-tetrahydrofuran-acetate buffer (pH 5) (62.5 5 32.5) containing 5 mmol octanesulfonate per liter. The flow rate was 2 mL/min. Recovery was 100%. The relative standard deviation for injection-to-injection reproducibility was 0.4% and that for sample-to-sample variation was 5% at high miconazole concentrations (30 pg/mL) and 1% at low (1 pg/mL) concentrations. The limit of detection was 250 ng/mL. 

Alhaique et al. [62] used a reversed phase high performance liquid chromatography method for the determination of miconazole in bulk or pharmaceuticals using bezafibrate as internal standard. 

Hasegawa et al. [76] measured miconazole serum concentration by a high performance liquid chromatographic method. The authors assessed whether the internal standard method produced an intra-assay error and found that the method gave more precise and more reproducible results compared to the absorption calibration curve method. With 0.5 pg/mL of miconazole, the coefficient of variation produced by that method was 3.41%, whereas that of the absorption calibration curve method was 5.20%. The concentration of absorptions calibration curve method showed higher values than the internal standard method. This indicated that the internal standard method was far more precise in measuring the miconazole serum concentrations than the absorption calibration curve method. 

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. 

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... 

Rao et al. reported a high performance liquid chromatographic method to determine diloxanide furoate and metronidazole in single and in combined dosage forms [41]. A 30 mg equivalent of diloxanide furoate and 25 mg of metronidazole (either as the bulk drug substances or in powdered tablets) was dissolved in methanol, amidopyrine added as the internal standard, and the mixture analyzed by HPLC at room temperature. The analytical column (30 cm x 3.9 mm) consisted of p-Bondapak Cig, with 9 9 1 1 methanol water 0.05 M KH2PO4 0.05 M NaH2P04 as the mobile phase. The flow rate was 1 mL/min), and detection was performed at 254 nm. 

Ito M, Ikeda K, Suzuki Y, Tanaka K, Saito M (2002) An improved fluorometric high-performance liquid chromatography method for sialic acid determination an internal standard method and its application to sialic acid analysis of human apolipoprotein E. Anal Biochem 300 260-266... 

Anon (1999a) Foodstuffs—Determination of acesulfame-K, aspartame and saccharin—High performance liquid chromatographic method. BS EN 12856 1999. Available from British standards or one of the other EU standards bodies. 

Kasiske et al. [219] have described a high performance liquid chromatographic method for six polynuclear aromatic hydrocarbons in trade effluents whose concentration in potable water is regulated by European Community standards, viz. fluoranthene, benzo(e)acetphen-anthracene benzo(k)fluoranthene, benzo(def)chrysene,... 

A high performance liquid chromatographic method was developed for the chiral separation of new selective PDE5 inhibitors, tadalafil and its three isomers [47]. The chiral separation was performed on a Chiralpak AD column. The mobile phase was hexane-isopropyl alcohol (1 1, v/v). UV detection was at 220 nm. Baseline chiral separation for the four isomers was obtained within 30 min. Each of the resolutions of the two pairs enantiomers were more than 2.0. The limits of quantitation were 0.60, 0.90, 1.20, and 1.80 ng for (6R,12aS), (6R,12aR), (6S, 12aS), and (6S,12aR) isomers, respectively. Relative standard deviation of the method was below 2% (n = 5). The method is suitable in quality control. 

Farthing, D. Karnes, T. Gehr, T.W. March, C. Fakhry, I. Sica, D.A. External-standard high-performance liquid chromatographic method for quantitative determination of furosemide in plasma by using solid-phase extracd ion and on-line elution. J.Pharm.Sci., 1992, 81, 569-571... 

Feige GB, Lumbsch HT, Huneck S, Elix JA (1993) Identification of lichen substances by a standardized high-performance liquid chromatographic method. J Chromatogr 646 417-427... 

High performance liquid chromatography is used for the separation and quantitative analysis of a wide variety of mixtures, especially those in which the components are insufficiently volatile and/or thermally stable to be separated by gas chromatography. This is illustrated by the following method which may be used for the quantitative determination of aspirin and caffeine in the common analgesic tablets, using phenacetin as internal standard where APC tablets are available the phenacetin can also be determined by this procedure. 

In a study of the metabolism of methyl parathion in intact and subcellular fractions of isolated rat hepatocytes, a high performance liquid chromatography (HPLC) method has been developed that separates and quantitates methyl parathion and six of its hepatic biotransformation products (Anderson et al. 1992). The six biotransformation products identified are methyl paraoxon, desmethyl parathion, desmethyl paraoxon, 4-nitrophenol, />nitrophenyl glucuronide, and /wiitrophenyl sulfate. This method is not an EPA or other standardized method, and thus it has not been included in Table 7-1. 

Bogusz, M., Franke, J. P., de Zeeuw, R. A., and Erkens, M., An overview of the standardization of chromatographic methods for screening analysis in toxicology by means of retention indices and secondary standards. Part II. High performance liquid chromatography, Fresenius ]. Anal. Chem., 347, 73, 1993. 

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