摘要:

Tryptophan (TP), 5-hydroxytryptophan (5-HTP), 3-indoleacetic acid (IAA) and serotonin (5-HT) were separated by TLC, with chloroform-methanol-ammonia (12-7-1) (v-v-v) as eluent and cellulose as stationary phase. A fibre optic-based fluorescence instrument for in situ scanning was used for quantitative measurements. The compounds were determined over the range 10–100 ng, with relative standard deviations between 1.70–6.52% and detection limits over the range 16.39–22.50 ng.

ISSN:1082-6076    

DOI:10.1080/10826079608005530

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A reverse phase liquid chromatographic procedure with fluorescence detection for the simultaneous determination of zopiclone and its main metabolites, N-desmethylzopiclone and zopiclone-N-oxide, in serum, blood and urine is described. An aliquot (0.5–1 mL) of the sample after the addition of 0.25 mL of 250 ng/mL solution of harmane in 0.2 M NaH2PO4as the internal standard is passed through a 1-mL BondElut C18silica extraction column. The column is selectively washed with water and acetonitrile to remove polar, neutral and acidic compounds. The desired compounds are eluted with a 0.25 mL aliquot of a mixture of methanol + 35% perchloric acid (100:1 v/v). A 10–25 μL aliquot of the eluate is injected onto a 150 × 4.6 mm I.D. column packed with 5-μm C18silica particles which is eluted at ambient temperature with a mobile phase of acetonitrile - 0.1% tetramethylammonium perchlorate (17:83 v/v) adjusted to pH 3.8 with 10% perchloric acid at a flow rate of 1.8 mL/min. The peaks are detected with a fluorescence detector (ex = 320 nm, em = 520 nm). The extraction recovery of all the compounds is in the range of 90–95%. The chromatogram is clean and the desired peaks are well separated from each other and from extraneous peaks.

ISSN:1082-6076    

DOI:10.1080/10826079608005531

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A high performance liquid chromatography procedure has been developed for the assay of an ondansetron hydrochloride and diphenhydramine hydrochloride mixture in 0.9% sodium chloride injection. The separation and quantitation were achieved on a 5-μm Spherisorb ODS-1 column at ambient temperature using a mobile phase of 60:40 v/v 0.1 M phosphate buffer pH 4.5-acetonitrile at flow rate of 1.2 mL/min. with detection of both analytes at 210 nm. The separation was achieved within 22 min. with sensitivity in the ng/mL range for each analyte. The method showed linearity for ondansetron and diphenhydramine in the 0.40–6.40 and 5.0–80.0 μg/mL ranges, respectively. Intra- and inter-day RSD values were 1.8% and 2.8–3.8% for ondansetron, and 1.4–1.7% and 2.0–2.7% for diphenhydramine, respectively. Accuracy of intra and inter-day were in the 1.0–1.6% and 1.2% for ondansetron and 0.7–2.0% and 0.3–3.8% for diphenhydramine, respectively. The limits of detection for ondansetron and diphenhydramine were 70 and 105 ng/mL, respectively, based on a signal to noise ratio of 3 and a 20 μL injection.

ISSN:1082-6076    

DOI:10.1080/10826079608005532

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Validation of analytical methodologies is widely recognized as an important aspect of the development/utilization of analytical procedures and is widely required in support of product registration applications. Detailed, specific and comprehensive guidelines for the performance of analytical validations are not universally available. In this manuscript, the role and concept of validation is defined, the necessity for validation is established and published guidelines related to appropriate validation parameters are reviewed. The validation of chromatographic methods for pharmaceutical applications is particularly emphasized.

ISSN:1082-6076    

DOI:10.1080/10826079608005533

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Validation of analytical methodologies is an important aspect of their development/utilization and is widely required in support of product registration applications. In this manuscript, definitions, procedures and acceptance criteria which appear in the pharmaceutical literature are summarized for the more commonly encountered validation parameters. Parameters examined include accuracy, precision, specificity, linearity and sensitivity limits.

ISSN:1082-6076    

DOI:10.1080/10826079608005534

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The possibility of using micellar sodium dodecyl sulfate mobile phase modified with n-propanol to separate six PAHs on apolar columns was examined. The large capacity factors found in large-chain stationary phases made the analysis impractical. The use of short-chain stationary phases and the presence of n-propanol in the mobile phase, as a modifier, significantly decreased the capacity factors but also decreased resolution, allowing separation of five PAHs in reasonable analysis times. Conditioning of the column was easy and reproducible but the effect of temperature was quite critical. The gradient technique decreased peak width significantly.

ISSN:1082-6076    

DOI:10.1080/10826079608005535

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The separation and the estimation of several main glycolipid classes as well as of some of these classes into main subclasses (or species) by reverse phase and normal phase high performance liquid chromatography and UV detection, is described.

ISSN:1082-6076    

DOI:10.1080/10826079608005536

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A simple HPLC method has been developed for the determination of organic acids adsorbed on particles of maghemite. The advantage of this described technique is the possibility to identify and measure the ratios of differents acids bounded on the same particle. The chromatographic analysis is achieved on a sulphonated copolymer column in acidic form. Good recoveries of the acids were obtained by dosing the free acids in the supernatant and the acids adsorbed on the particles.

ISSN:1082-6076    

DOI:10.1080/10826079608005537

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This paper presents the values of the micellar binding constants of Ni(II), Co(II) and Cu(II) as complexes with sodium diethyldithiocarbamate, DDTC, in presence of hexadecyltrimethylammonium bromide, CTAB, and sodium dodecylsulphate, SDS, with larger amounts of n-Propanol as organic modifier, by High Performance Liquid Chromatography. Binding constants have been obtained from two equations: a) Arunyanart's treatment, very used for organic compounds but that is not take into account the influence of modifier and b) a multiple regression analysis that permits to consider the high quantities of n-Propanol.

ISSN:1082-6076    

DOI:10.1080/10826079608005538

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Favourable chromatographic conditions for separation of Pt and Rh were achieved on microcrystalline cellulose with solvent system methylisobutyl ketone - conc. HCl (40+60, v/v) and KI in ethanol as detection reagent; narow, compact and coloured bands on white background (RF0.44 for Rh and 0.76 for Pt) were obtained.

ISSN:1082-6076    

DOI:10.1080/10826079608005539

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor