scholarly journals The Liquid Chromatographic Determination of Chlorogenic and Caffeic Acids in Xu Duan (Dipsacus asperoides) Raw Herb

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Jarryd L. Pearson ◽  
Samiuela Lee ◽  
Harsha Suresh ◽  
Mitchell Low ◽  
Marnilar Nang ◽  
...  
Keyword(s):  
Formic Acid ◽  
Chlorogenic Acid ◽  
Analytical Method ◽  
Mobile Phase ◽  
Chromatographic Determination ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Acid Precursor ◽  
Aqueous Formic Acid

A validated analytical method is reported for the analysis of chlorogenic and caffeic acids in Xu Duan (Dipsacus asperoides) in the dried raw herb. The ground samples were extracted by ultrasonication in water and the extract was analysed by LC-PDA with identity confirmation by (+)ESI-MS/MS. A C18 column was used with a 0.1% aqueous formic acid : methanol gradient mobile phase. The analytes were quantified 325 nm. With the MS detector, using the chlorogenic acid precursor ion with m/z 354, ions with m/z 191, and 85 were produced. For caffeic acid the precursor ion with m/z 181, ions with m/z 163, 135, and 89 were produced. The amount of chlorogenic and caffeic acids in the raw herb was found to be 4.46 and 0.63 mg/g, respectively, and the method LOD was 0.13 and 0.02 mg/g, respectively.

Improved liquid-chromatographic determination of haloperidol in plasma.

1984 ◽  
Vol 30 (7) ◽  
pp. 1228-1230 ◽  
Author(s):  
A K Dhar ◽  
H Kutt
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Room Temperature ◽  
Internal Standard ◽  
Isoamyl Alcohol ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract This method for determination of haloperidol in plasma is based on "high-performance" isocratic liquid chromatography with the use of a C8 bonded reversed-phase column at room temperature. Haloperidol and the internal standard (chloro-substituted analog) are extracted from alkalinized plasma into isoamyl alcohol/heptane (1.5/98.5 by vol) and back-extracted into dilute H2SO4. The aqueous phase is directly injected onto the column. The mobile phase is a 30/45/25 (by vol) mixture of phosphate buffer (16.5 mmol/L, pH 7.0), acetonitrile, and methanol. Unlike other liquid-chromatographic procedures for haloperidol, commonly used psychotropic drugs do not interfere. Analysis can be completed within an hour. The procedure is extremely sensitive (1.0 microgram/L) and is well reproducible (CV 5.6% for a 2.5 micrograms/L concentration in plasma).

Liquid Chromatographic Determination of Carbofuran in Technical and Formulated Products: Collaborative Study

1986 ◽  
Vol 69 (5) ◽  
pp. 915-918
Author(s):  
Edward J Kikta ◽  
◽  
E Bane ◽  
A Burns ◽  
A Christensen ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Data Sets ◽  
Matched Pairs ◽  
Reverse Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method for the analysis of technical and formulated carbofuran samples was evaluated in a collaborative study. Carbofuran is determined by reverse phase LC, using a water-methanol mobile phase and acetophenone as internal standard, and detected at 280 nm. Twelve samples, 5 formulations and technical matched pairs, were analyzed by 17 collaborating laboratories. Accuracy and variability of results are typical of large LC data sets. The method has been adopted official first action.

Liquid Chromatographic Determination of Ergot Alkaloids in Wheat

1986 ◽  
Vol 69 (4) ◽  
pp. 697-699
Author(s):  
George M Ware ◽  
Allen S Carman ◽  
Octave J Francis ◽  
Shia S Kuan
Keyword(s):  
Mobile Phase ◽  
Ergot Alkaloids ◽  
Ammonium Phosphate ◽  
Ammonium Hydroxide ◽  
Chromatographic Determination ◽  
Resin Column ◽  
Fluorescence Detector ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method is described for the determination of individual ergot alkaloids in wheat. The sample is extracted with ethyl acetate-4% ammonium hydroxide (100 + 10), and the extract is cleaned up by liquidliquid partition. The ergot alkaloids are resolved by liquid chromatography (LC), using a porous cross-linked polystyrene-divinylbenzene resin column and a mobile phase consisting of acetonitrile-0.05M dibasic ammonium phosphate (55 + 45) buffered at pH 10.0. The ergot alkaloids ergonovine, ergonovinine, ergotamine, ergotaminine, α-ergocryptine, α-ergocryptinine, ergocristine, and ergocristinine are separated by LC and detected with a fluorescence detector. Recovery of ergot alkaloids added to wheat at levels of 16-760 ng/g averaged 85.6% with a coefficient of variation of 11.1%.

scholarly journals Micellar Liquid Chromatographic Determination of Carbaryl and 1-Naphthol in Water, Soil, and Vegetables

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Mei-Liang Chin-Chen ◽  
Maria Rambla-Alegre ◽  
Abhilasha Durgbanshi ◽  
Devasish Bose ◽  
Sandeep K. Mourya ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Limit Of Detection ◽  
Cetylpyridinium Chloride ◽  
Sodium Dodecyl ◽  
Chromatographic Determination ◽  
Limit Of Quantification ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

A liquid chromatographic procedure has been developed for the determination of carbaryl, a phenyl-N-methylcarbamate, and its main metabolite 1-naphthol, using a C18 column (250’mm’ × ’4.6’mm) with a micellar mobile phase and fluorescence detection at maximum excitation/emission wavelengths of 225/333’nm, respectively. In the optimization step, surfactants sodium dodecyl sulphate (SDS), Brij-35 andN-cetylpyridinium chloride monohydrate, and organic solvents propanol, butanol, and pentanol were considered. The selected mobile phase was 0.15’M SDS-6% (v/v)-pentanol-0.01’M NaH2PO4buffered at pH 3. Validation studies, according to the ICH Tripartite Guideline, included linearity (r>0.999), limit of detection (5 and 18’ng mL-1, for carbaryl and 1-naphthol, resp.), and limit of quantification (15 and 50’ng mL-1, for carbaryl and 1-naphthol, resp.), with intra- and interday precisions below 1%, and robustness parameters below 3%. The results show that the procedure was adequate for the routine analysis of these two compounds in water, soil, and vegetables samples.

scholarly journals Liquid Chromatographic Determination of Mebendazole and its Metabolites, Aminomebendazole and Hydroxymebendazole, in Eel Muscle Tissue

1996 ◽  
Vol 79 (3) ◽  
pp. 645-651 ◽  
Author(s):  
Christiaan A J Hajee ◽  
Nel Haagsma
Keyword(s):  
Muscle Tissue ◽  
Mobile Phase ◽  
Solid Phase ◽  
Chromatographic Determination ◽  
Extraction Column ◽  
Phase Extraction ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract An analytical method is presented for liquid chromatographic (LC) determination of mebendazole (MBZ), hydroxymebendazole (MBZ-OH), and aminomebendazole (MBZ-NH2) in eel muscle tissue. Muscle tissue is extracted with ethyl acetate at pH 7.5. After addition of n-hexane, the extract is cleaned up and concentrated on an aminopropyl solid-phase extraction column. The test solutions are analyzed isocratically on a ChromSpher B LC column with acetonitrile–phosphate buffer, pH 6.2, as mobile phase. Limits of detection and quantitation were 0.7 and 1.1 ¼g/kg, respectively, for MBZOH; 1.4 and 2.3 ¼g/kg, respectively, for MBZ; and 1.5 and 2.1 ¼g/kg, respectively, for MBZ-NH2. Interand intraday coefficients of variation were 3.5 and 3.4%, respectively, for MBZ-OH; 2.5 and 3.1%, respectively, for MBZ; and 5.8 and 4.8%, respectively, for MBZ-NH2. Mean recoveries were 90% for MBZ, 74% for MBZ-NH2, and 92% for MBZ-OH. A linear range of applicability of at least 10–1000 ¼g/kg was found for each analyte. Incurred MBZ-NH2 (181.3 ¼g/kg) was identified in eel muscle tissue apart from MBZ (23.7 ¼g/kg) after 48 h exposure ina treatment bath containing MBZ at 1 mg/L.

Improved liquid-chromatographic determination of 3-methoxy-4-hydroxyphenylethyleneglycol in urine with electrochemical detection.

1984 ◽  
Vol 30 (1) ◽  
pp. 140-143 ◽  
Author(s):  
J R Shipe ◽  
J Savory ◽  
M R Wills
Keyword(s):  
Mobile Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Improved Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Mean Concentration ◽  
Phase Column

Abstract In this improved method for quantifying 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) in urine, after a multistep extraction of MHPG and internal standard (iso-MHPG) from 3.0 mL of urine, the compounds are separated on a C18 reversed-phase column and quantified by use of an electro-chemical detector. The isocratic chromatographic separation takes about 16 min. The mobile phase is phosphate buffer/acetonitrile (88/12 by vol), the flow rate 0.7 mL/min. Recycling the mobile phase and automating the sample injection make possible the unattended assay of more than 70 samples per day. The within-run precision of the method is excellent (CV 1.8%) at a mean concentration of 1.1 mg/L.

Liquid Chromatographic Determination of Protein Acid Hydrolysate Content in Blended Soy Sauce

1985 ◽  
Vol 68 (4) ◽  
pp. 618-621
Author(s):  
Shih-Ling Yeh-Chen ◽  
Chin-Tan Hsu
Keyword(s):  
Liquid Chromatography ◽  
Mobile Phase ◽  
Levulinic Acid ◽  
Protein Hydrolysate ◽  
Chromatographic Determination ◽  
Soy Sauce ◽  
Acid Hydrolysate ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Five methods were investigated for the determination of levulinic acid in soy sauce to determine the addition of protein hydrolysate, mainly acid hydrolysate of defatted soybeans. Best results were obtained by using liquid chromatography (LC) with 0.004M HC104 as the mobile phase and bromcresol purple as a post-column reagent. An innovative LC method with 0.1% H3PO4 as eluant was developed for determination of levulinic acid at 280 nm in soy sauce. This was the most timesaving method.

Liquid Chromatographic Determination of Coumarin Anticoagulants in Tablets: Collaborative Study

1987 ◽  
Vol 70 (5) ◽  
pp. 834-836
Author(s):  
Ella S Moore
Keyword(s):  
Mobile Phase ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Content Uniformity ◽  
Photometric Detection ◽  
Warfarin Sodium ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for the determination of coumarin anticoagulants in tablets was collaboratively studied by 7 laboratories. The method uses an octadecylsilane-bonded microparticulate column, tetrahydrofuran-methanol-water-acetic acid mobile phase, and photometric detection at 311 nm. Each collaborator received samples of warfarin sodium, phenprocoumon, and dicumarol as a synthetic composite and as commercial individual and composited tablets. Pooled average assay values for synthetic and commercial tablet samples of warfarin sodium were 101.6 and 99.5%, respectively, with a combined reproducibility SD of 2.38% (CV = 2.37%) and combined repeatability SD of 1.49% (CV = 1.49%). Pooled average (SD) assay values for dicumarol and phenprocoumon commercial samples were 98.0 (2.27) and 101.3% (4.00), respectively. The content uniformity determinations of 2 mg warfarin sodium and 25 mg dicumarol tablets indicated average tablet contents (range) of 99.5% (91.0-116.0) and 98.0% (89.8-108.8), respectively. The method has been approved interim official first action

Isolation, Purification, and Liquid Chromatographic Determination of Stilbene Phytoalexins in Peanuts

1995 ◽  
Vol 78 (5) ◽  
pp. 1177-1182 ◽  
Author(s):  
Victor S Sobolev ◽  
Richard J Cole ◽  
Joe W Dorner ◽  
Boris Yagen
Keyword(s):  
Acetic Acid ◽  
Silica Gel ◽  
Mobile Phase ◽  
High Speed ◽  
Chromatographic Determination ◽  
Normal Phase ◽  
Phase Partition ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method for determination of stilbene phytoalexins (SPs) in peanuts has been developed. SPs were extracted with acetonitrile–water (90 + 10, v/v) by high-speed blending. An aliquot of extract was applied to a minicolumn packed with AI2O3–ODS (C18) mixture and eluted with acetonitrile-water (90 + 10, v/v). Eluate was evaporated under nitrogen, and residue was dissolved in LC mobile phase. SPs in an aliquot of purified extract were quantitated by normal-phase partition LC on silica gel with n-heptane–2-propanol–water–acetonitrile–acetic acid (1050 + 270 + 17 + 5 + 1, v/v) as mobile phase. Recoveries of SPs [frans-4-(3-methyl-but-1-enyl)-3,5,4′-trihy-droxystilbene (trans-arachidin-3; t-Ar-3), trans-3-isopentadienyl-4,3′,5′-trihydroxystilbene (t-IPD), and trans-3,5,4′-trihydroxystilbene (trans-resveratrol; t-Res)] from peanuts spiked at 300 ppb were 96.05 ± 2.8%. Limits of quantitation for t-Ar-3 and t-IPD were about 100 ppb. t-Ar-3, t-IPD, and t-Res were found in all parts of the peanut plant as major SPs produced in response to fungal invasion.

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