Quantitative High-performance Liquid Chromatography Analysis Research Articles

Qualitative and quantitative high-performance liquid chromatographic analysis of aldehydes in Brazilian sugar cane spirits and other distilled alcoholic beverages

A study is presented on the high-performance liquid chromatographic analysis of eighteen aldehydes in Brazilian sugar cane spirits and other international brandies. The aldehydes were separated by reversed-phase high-performance liquid chromatography as 2,4-dinitrophenylhydrazones (DNPHs). A very good chromatographic separation was achieved for eighteen different aldehyde-DNPHs. The proposed methodology is quite simple and not very time-consuming. Ten aldehydes were identified in 75 beverages and quantified using the external standard method with UV detection at 365 nm. A detailed knowledge of the aldehyde content should significantly contribute to improving the quality control of distilled spirits.

Determination of atropine in pharmaceutical preparations by liquid chromatography with fluorescence detection

A method is described for the determination of atropine in pharmaceutical preparations by precolumn derivatization and high-performance liquid chromatography (HPLC). Atropine is derivatized by reacting with 1-anthroylnitrile (1-AN) in acetone. The 1-AN derivative of atropine is then used for quantitative HPLC analysis on a reversed-phase column with fluorescence detection. The calibration graph was linear over a sample concentration range from 0.05 to 1.0 μg/ml; the limit of detection was reached at a sample concentration of 0.01 μg/ml. The proposed method was satisfactorily applied to the determination of atropine in pharmaceutical preparations.

Intraspecific variation in the red alga Portieria hornemannii : monoterpene concentrations are not influenced by nitrogen or phosphorus enrichment

The red alga Portieria hornemannii (Lyngbye) Silva was selected to test the effects of enhanced nutrient availability on the production of carbon-based secondary metabolites, because of its notable site-to-site variation in monoterpene production. On Guam, the major secondary metabolite produced by this alga is ochtodene, a cyclic monoterpene. Quantitative high-performance liquid-chromatography analysis of the extracts of P. hornemannii collected from six sites on Guam showed that both ochtodene and triglyceride concentrations differed significantly among sites. Internal nitrogen and phosphorus content of the algae did not correlate with the observed variation in chemistry. Experimental enhancement of N-alone, P-alone or N + P in the field for 5 wk failed to induce a significant change in ochtodene concentrations in the alga, while triglyceride concentrations increased significantly in the N + P treatment. Ochtodene and triglyceride concentrations did not change among similar treatments in shaded (18 d) and unshaded (11 d) fertilization experiments conducted in the laboratory. Variation in ochtodene concentrations in P. hornemannii cannot be attributed to N and P availability; however, the decrease in ochtodene and triglyceride concentrations during the shaded laboratory experiment suggests that light may be a factor influencing monoterpene biosynthesis. The difference in ochtodene concentration between the initial and final sets of field controls collected for the unshaded laboratory experiment suggests that temporal variation might also contribute to differences observed among the algae at the different sites.

Quantitative high‐performance liquid chromatography analysis of plant phospholipids and glycolipids using light‐scattering detection

LipidsVolume 31, Issue 5 p. 551-551 ErratumFree Access Quantitative high-performance liquid chromatography analysis of plant phospholipids and glycolipids using light-scattering detection This article corrects the following: Quantitative high-performance liquid chromatography analysis of plant phospholipids and glycolipids using light-scattering detection G. A. Picchioni, A. E. Watada, B. D. Whitaker, Volume 31Issue 2Lipids pages: 217-221 First Published online: February 1, 1996 G. A. Picchioni, G. A. PicchioniSearch for more papers by this authorA. E. Watada, A. E. WatadaSearch for more papers by this authorB. D. Whitaker, B. D. WhitakerSearch for more papers by this author G. A. Picchioni, G. A. PicchioniSearch for more papers by this authorA. E. Watada, A. E. WatadaSearch for more papers by this authorB. D. Whitaker, B. D. WhitakerSearch for more papers by this author First published: 01 May 1996 https://doi.org/10.1007/BF02522651 The online version of the original article can be found at http://dx.doi.org/10.1007/BF02522623 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume31, Issue5May 1996Pages 551-551 RelatedInformation

Liquid chromatographic determination of carnitine by precolumn derivatization with pyrene-1-carbonyl cyanide

A method is described for the determination of carnitine chloride in pharmaceutical preparations by precolumn derivatization and high-performance liquid chromatography (HPLC). Carnitine chloride is derivatized by reaction with pyrene-1-carbonyl cyanide (PCC) in dimethyl sulphoxide. The PCC derivative of carnitine is then used for quantitative HPLC analysis on a cation-exchange column with fluorescence detection. The calibration graph was linear over a sample concentration range from 2.0 to 20 μg/ml; the limit of detection was 0.5 μg/ml under the conditions studied. The proposed method was applied satisfactorily to the determination of carnitine chloride in pharmaceutical preparations.

Use of N-acetylpsychosine as internal standard for quantitative high-performance liquid chromatographic analysis of glycosphingolipids

The use of N-acetylpsychosine as an internal standard forthe quantitative high-performance liquid chromatography (HPLC) of p-nitrobenzoyl derivatives of glycosphingolipids is described. It is suitable because the chromogen reacts on equimolar basis with both N-acetylpsychosine and sample glycosphingolipids. The use of N-acetylpsychosine as an internal standard was validated by determining the glycosphingolipid content of a system of metastatic variants selected from a murine fibrosarcoma line (T3 cells). Reproducible results were obtained throughout several quantitative analyses of cellular glycosphingolipids and it was possible to determine the glycosphingolipid content of as few as 5 · 10 6 cells.

Quantitative high-performance liquid chromatography analysis of DNA oxidized in vitro and in vivo

Oxidative modification of genetic material has been implicated as a factor in carcinogenesis, particularly during promotion and progression, and therefore there is a need for sensitive detection of oxidized DNA bases. We developed a method that can be applied to DNA isolated from any source and used to simultaneously quantify oxidized nucleosides without a need to prelabel the DNA or use destructive hydrolytic procedures. This method is based on: (a) enzymatic DNA digestion; (b) HPLC separation of the resultant nucleosides; (c) acetylation of the oxidized nucleosides with [ 3H]Ac 2O (acetic anhydride); (d) removal of the radioactive debris; and (e) quantitative analysis of tritiated nucleoside acetates by HPLC. Enzymatic DNA digestion was optimized using DNase I in the presence of Mg 2+ (pH 7), followed by nuclease P1 in the presence of Zn 2+ (pH 5.1) and alkaline phosphatase (pH 7.5). Analysis of DNA oxidized with H 2O 2 in the presence of Fe 2+/EDTA for 30 min showed that the levels of 8-OHdG (8-hydroxy-2′-deoxyguanosine) were increased 2.7-fold, HMdU (5-hydroxymethyl-2′-deoxyuridine) 3.15-fold, and FdU (5-formyl-2′-deoxyuridine) 2.5-fold. Although the (−)-isomer of cis-dTG ( cis-thymidine glycol) was enhanced 2.3 times, the (+)-isomer remained virtually unchanged. Analysis of DNA isolated from epidermal cells of mice treated in vivo with the tumor promoter TPA (12- O-tetradecanoylphorbol 13-acetate) showed 4.8-, 2.7-, and 8.7-fold increases in the levels of total cis-dTG, 8-OHdG, and HMdU, respectively, and of some unknown DNA oxidation products. These results prove applicability of the 3H-postlabeling method to the analysis of DNA (and potentially RNA) isolated from many sources, including animals and humans.

Determination of the antihypertensive drug 1-[2-ethoxy-2-(3′-pyridyl)ethyl]-4-(2′-methoxyphenyl)piperazine (IP/66) in rat and human plasma by high-performance liquid chromatography and isotope dilution mass spectrometry

In connection with pharmacokinetic studies on the antihypertensive drug 1-[2-ethoxy-2-(3′-pyridyl)ethyl]-4-(2′-methoxyphenyl)piperazine (IP/66) (I), appropriate high-performance liquid chromatographic (HPLC) and gas chromatographic—mass spectrometric isotope dilution (GC—MS—ID) methods for its determination in rat and human plasma, respectively, were developed. In both techniques, deproteinized and basified plasma samples were extracted and purified by adsorption on an Extrelut-1 column, then the drug was eluted with dichloromethane. Quantitative HPLC analysis was performed on a C 8 reversed-phase column. The mobile phase was phosphate buffer (0.02 M, pH 2.8)—acetonitrile (65:35), with UV detection at 208 nm. The internal standard was 1-[2-butoxy-2-(3′-pyridyl)ethyl]-4-(2′-methoxyphenyl)piperazine, a homologue of I. The inter-assay coefficient of variation (C.V.) was 9.9% for a drug level of 2 μg/ml. Quantitative GC—MS—ID analysis was performed with a DB-17 fused-silica capillary column using the selected-ion monitoring technique. The deuterated form of I, 1-[2-ethoxy-2-(3′-pyridyl)ethyl]-4-2′-trideuteromethoxyphenyl)-piperazine, utilized as internal standard, was synthesized. The inter-assay C.V. was 7.36% for a drug level of 1 ng/ml.

Quantitative HPLC analysis of acidic opines by phenylthiocarbamyl derivatization

A new method for the quantitative analysis of acidic opines—alanopine, strombine, tauropine, and β-alanopine—is presented. The method is based on formation of phenylthiocarbamyl (PTC) derivatives of the acidic opines after partial purification by ion-exchange chromatography. The PTC acidic opines are separated by reverse-phase high-performance liquid chromatography (HPLC) and detected within 20 min by ultraviolet absorbance. This HPLC method gives higher sensitivity, 10–30 pmol minimum detection, and better reproducibility than the high-voltage paper electrophoresis method. There is also good agreement for the three acidic opines (alanopine, strombine, and tauropine) when compared by HPLC and electrophoresis methods. Accumulation of β-alanopine was observed for the first time in the adductor muscle of blood shell, Scapharca broughtonii, during aerial exposure by application of the HPLC detection method.

5] Quantitative high-performance liquid chromatographic analysis of branched-chain 2-keto acids in biological samples

5] Quantitative high-performance liquid chromatographic analysis of branched-chain 2-keto acids in biological samples

Quantitative high-performance liquid chromatographic analysis of dabsyl-amino acids within 14 min

Quantitative high-performance liquid chromatographic analysis of dabsyl-amino acids within 14 min

Improved high-performance liquid chromatographic analysis of some carboxylic acids in food and beverages as their p-nitrobenzyl esters

An improved, straightforward and accurate method for the derivatization and quantitative high-performance liquid chromatographic analysis of carboxylic acids in food and beverages is presented. Thirty-two p-nitrobenzyl esters were prepared in high yields by direct reaction of the free acid with O-(4-nitrobenzyl)-N,N′-diisopropylisourea in dioxane—water (9:1). Benzylmalonic acid was used as a new internal standard. Excess of reagent was removed on a strong cation-exchange resin. The advantage of this original and very convenient procedure over the usual clean-up step involving filtration through a disposable silica cartridge is discussed. The p- nitrobenzyl ester derivatives were readily separated using a single linear gradient of solvent (acetonitrile in water). With a high-performance liquid chromatography column of conventional size (20–25 cm x 4.6 mm I.D.), the analysis lasted for less than 20 min. This analysis time was even shorter (< 12 min) when using modern small-bore (100 x 2.1 mm I.D.) columns. Applications of the method to the analysis of the main carboxylic acids in coffee, wine and fruit juices are presented.

Micro analysis of prostaglandins and ecdysteroids in insects by high-performance liquid chromatography and fluorescence labeling

A method is discussed for the quantitative determination of prostaglandins and ecdysteroids in insects by pre-column derivatization and high-performance liquid chromatography. Prostaglandin and ecdysteroid fractions are first purified from homogenized insect organs by a Sep-Pak C 18 cartridge and derivatized quantitatively by treatment with 1-anthroyl nitrite. These derivatives are then used for quantitative high-performance liquid chromatography analysis on a C 18 column equipped with fluorescence detection. The detection limit is presently below 10 pg as an injected amount of the standard derivatives. The foregoing methods are applied for the determination of the prostaglandin and ecdysteroid titers in the various organs of an individual insect.

Improved fluorometric method for quantitative high-performance liquid chromatographic analysis of methylated guanine derivatives in DNA

Improved fluorometric method for quantitative high-performance liquid chromatographic analysis of methylated guanine derivatives in DNA

Contribution of nitropyrene to the mutagenic activity of coal fly ash.

Stack-collected coal fly ash from western low-sulfur coal was extracted with 60:40 benzene/methanol. This extract was fractionated by preparative-scale high performance liquid chromatography (HPLC) and the mutagenic activity of 14 fractions was evaluated by microbial assay with Salmonella typhimurium TA1538. A widespread distribution of direct-acting mutagens, which probably includes both mono- and dinitroaromatics, was detected. HPLC methods were also used to isolate 1-nitropyrene from the total benzene/methanol extract. The identification of 1-nitropyrene was based on gas chromatographic and HPLC retention measurements and mass spectral data. The concentration of 1-nitropyrene in the ash extract was determined by quantitative HPLC analyses. Mutagenicity assays of the total extract and an authentic 1-nitropyrene standard with Salmonella strains TA1538, TA100, and TA98 indicated that the 1-nitropyrene accounts for approximately 0.03-0.16% of the total mutagenic activity of the extract.

Quantitative high-performance liquid chromatographic analysis of the bitter quassinoid compounds from Simaruba glauca seeds

Quantitative high-performance liquid chromatographic analysis of the bitter quassinoid compounds from Simaruba glauca seeds

Quantitative high-performance liquid chromatographic analysis of the commercial dyestuff G acid and Gama acid

A convenient and accurate quantitative analytical method for the commercial dye products G acid, and Gama acid, has been established by ion-pair reversed-phase high-performance liquid chromatography. Good resolution among G acid, Schaeffer acid, R acid, Gama acid and amino-G acid was achieved. Appropriate selection of UV detection wavelength, 230 nm, has resulted in linear absorption responses over a wide concentration range, 0–8 μg. The application of the method to a study of the rate of ammonolysis of G acid to amino-G acid is described.

Quantitative high-performance liquid chromatographic analysis of 14C-labelled photosynthetic intermediates in isolated intact chloroplasts

A rapid quantitative separation of photosynthetic intermediates in spinach chloroplasts is obtained on chemically modified, totally porous, silica gel resins (10 μm). Sugars are separated on a polar resin (LiChrosorb NH 2) by a weakly polar eluent (acetonitrile-water), while phosphorylated compounds are eluted by a phosphate gradient on a strongly basic anion exchanger (LiChrosorb AN). The separation of phosphate esters is complete in ca. 1 h. Activity of labelled compounds is monitored on-line by means of a solid scintillator and a multi-channel analyzer.

Quantitative high-performance liquid chromatographic analysis of 12-oxo-dodeca-4,8-dienoic acid and its by-products in the nylon 12 process

Quantitative high-performance liquid chromatographic analysis of 12-oxo-dodeca-4,8-dienoic acid and its by-products in the nylon 12 process