High Performance Liquid Chromatographic Determination of Lactose in Milk

1981 ◽  
Vol 64 (4) ◽  
pp. 805-807
Author(s):  
Leslie G West ◽  
Marie A Llorente
Keyword(s):  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Chocolate Milk ◽  
Silica Column ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A rapid and simple high performance liquid chromatographic method for the determination of lactose in milk was developed. Samples were diluted with 0.5% perchloric acid and centrifuged, and an aliquot of the supernate was mixed with acetonitrile. Lactose was separated on a 10 μm particle-size silica column with aqueous acetonitrile as the mobile phase. The recovery of lactose from whole, skim, and chocolate milk averaged 99.2, 101.1, and 100.4%, respectively. Coefficients of variation for routinely performed duplicate determinations are between 1.0 and 1.5%.

High Performance Liquid Chromatographic Determination of Carbaryl Insecticide in Formulations

1980 ◽  
Vol 63 (3) ◽  
pp. 650-652
Author(s):  
William H Mcdermott
Keyword(s):  
High Performance ◽  
Methylene Chloride ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Modified Silica Gel ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high performance liquid chromatographic method for carbaryl in formulations has been developed and used to assay 3 formulations in a 10-day repeatability study. The method uses a cyano modified silica gel column packing and a mobile phase of heptane-methylene chloride-isopropanol-methanol (60+35+4.8+0.2). The coefficients of variation for 2 wettable powders and one aqueous flowable formulation were 0.61, 0.62, and 0.75%, respectively. It is recommended that a collaborative study be conducted on this method.

High Performance Liquid Chromatographic Determination of Methapyrilene Hydrochloride in Feed and Sleep Aid Tablets

1981 ◽  
Vol 64 (4) ◽  
pp. 889-892
Author(s):  
Badaruddin Shaikh ◽  
Margarette R Hallmark
Keyword(s):  
High Performance ◽  
Ammonium Carbonate ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reverse Phase ◽  
Phase Partition ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Methapyrilene hydrochloride (MP·HCl) was extracted from feed with methanol and determined by reverse phase partition chromatography in less than 15 min, using isocratic elution with acetonitrile-1.1% ammonium carbonate (1 + 1) as the mobile phase. This procedure was tested on feed treated with MP·HCl at levels of 125,500, and 2000 ppm. Recoveries were 104,95, and 96% with coefficients of variation of 2.4,1.6, and 0.6%, respectively. MP·HCl in feed was stable for 14 days. This method was also successfully used to determine MP·HCl in 3 sleep aid tablets.

Liquid-chromatographic determination of amitryptyline and its metabolites in serum, with adsorption onto glass minimized.

1982 ◽  
Vol 28 (10) ◽  
pp. 2143-2148 ◽  
Author(s):  
P M Edelbroek ◽  
E J de Haas ◽  
F A de Wolff
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Isoamyl Alcohol ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Irreversible Adsorption ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract To study correlations between the concentrations, in serum, of amitriptyline and its most important metabolites with clinical response in patients, we developed a "high-performance" liquid-chromatographic method for routine determination of amitriptyline, nortriptyline, total 10-hydroxy-amitriptyline, desmethylnortriptyline, and E(trans)- and Z(cis)-10-hydroxynortriptyline. These compounds are extracted from 1 mL of alkalinized serum into hexane/isoamyl alcohol (99/1 by vol). Perazine is the internal standard. To minimize irreversible adsorption of the drugs onto the glassware, 5 micrograms of maprotiline is added to the organic phase just before evaporation. After a 10-min resolution on a silica column eluted with acetonitrile/methanol/NH4OH (1 mol/L), absorbance is measured at 240 nm. Only chlorimipramine, doxepin, procainamide, and N-acetylprocainamide may interfere with assay of the compounds that probably are therapeutically relevant: amitriptyline, nortriptyline, and E-10-hydroxynortriptyline. Uremia, lipemia, and icterus also do not affect the analysis.

High Performance Liquid Chromatographic Determination of Phenothiazine Residues in Sheep Tissues

1980 ◽  
Vol 63 (5) ◽  
pp. 988-991
Author(s):  
Graeme L Blackman ◽  
Ah Chai Ho ◽  
Alex Jozsa ◽  
John D Kelly
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Tissue Samples ◽  
Silica Column ◽  
Liquid Chromatographic Determination ◽  
Residue Levels ◽  
Liquid Chromatographic

Abstract A high performance liquid chromatographic (HPLC) technique is described for the determination of residue levels of the anthelmintic drug phenothiazine in sheep tissues. Phenothiazine was administered to sheep which were slaughtered after withholding periods of 24, 48, and 72 h. Residues of phenothiazine were then extracted from tissue samples by homogenization in methanol. The HPLC analysis of the extracts involved separation on a 10 μm silica column using a mobile phase of 0.3% n-propanol in cyclohexane. The lower limit of detection by ultraviolet absorption at 254 nm was 0.05 ppm

Liquid-chromatographic determination of 5-fluorocytosine.

1980 ◽  
Vol 26 (1) ◽  
pp. 117-119
Author(s):  
J O Miners ◽  
T Foenander ◽  
D J Birkett
Keyword(s):  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Therapeutic Monitoring ◽  
Pharmacokinetic Studies ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We report a "high-performance" liquid-chromatographic method for measuring 5-fluorocytosine in plasma and cerebrospinal fluid. After deproteinization with trichloroacetic acid, the supernates are chromatographed on a reversed-phase (C18) column. Response to concentration is linear in the range of 5 to 200 mg/L, with ultraviolet detection at 276 nm. The assay requires only 0.1 mL of plasma, is reproducible, and may be performed in less than 12 min. 5-Fluorocytosine concentrations determined by this procedure correlated well with those obtained by spectrofluorometry, although the present method is more specific with no observable interference from co-administered amphotericin B and most other commonly encountered drugs, including salicylat:. This method is applicable to the routine therapeutic monitoring of pediatric and adult patients as well as to pharmacokinetic studies.

Liquid-chromatographic determination of 5-fluorocytosine.

1980 ◽  
Vol 26 (1) ◽  
pp. 117-119 ◽  
Author(s):  
J O Miners ◽  
T Foenander ◽  
D J Birkett
Keyword(s):  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Therapeutic Monitoring ◽  
Pharmacokinetic Studies ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We report a "high-performance" liquid-chromatographic method for measuring 5-fluorocytosine in plasma and cerebrospinal fluid. After deproteinization with trichloroacetic acid, the supernates are chromatographed on a reversed-phase (C18) column. Response to concentration is linear in the range of 5 to 200 mg/L, with ultraviolet detection at 276 nm. The assay requires only 0.1 mL of plasma, is reproducible, and may be performed in less than 12 min. 5-Fluorocytosine concentrations determined by this procedure correlated well with those obtained by spectrofluorometry, although the present method is more specific with no observable interference from co-administered amphotericin B and most other commonly encountered drugs, including salicylat:. This method is applicable to the routine therapeutic monitoring of pediatric and adult patients as well as to pharmacokinetic studies.

Rapid High Performance Liquid Chromatographic Determination of Monosodium Glutamate in Food

1982 ◽  
Vol 65 (3) ◽  
pp. 567-571
Author(s):  
Peter Sporns
Keyword(s):  
Glutamic Acid ◽  
High Performance ◽  
Monosodium Glutamate ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Soy Sauce ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A rapid, accurate high performance liquid chromatographic method is described for determination of glutamic acid in food. Average recovery of added glutamic acid was 99.2% by this method. The method could be used to analyze samples such as soy sauce, which contain a large amount of other potentially interfering soluble compounds.

High Performance Liquid Chromatographic Determination of Clocapramine in Feed and Plasma

1982 ◽  
Vol 65 (3) ◽  
pp. 706-710
Author(s):  
Aziz Geahchan ◽  
Paul Chambon ◽  
Pierre Genoux
Keyword(s):  
High Performance ◽  
Animal Feed ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Plasma Samples ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high performance liquid chromatographic method is described for the determination of clocapramine in animal feed and plasma. Samples are made alkaline and then extracted with chloroform containing opipramol as internal standard. For plasma samples, the organic phase is evaporated to dryness under a stream of nitrogen, and the residue is dissolved in dichloromethane-methanol. Extracts are chromatographed on silica gel with dichloromethane-methanol-ammonia (100 + 10 + 0.25) as eluant, and quantitated using an internal standard. Within-day precision for plasma extracts (n = 15) was 3.39, 5.7, and 4.13% at 5,10, and 15 mg clocapramine/L plasma, respectively, and day-to-day precision was 4.6, 6.8, and 4.4% at the same levels. The detection limit was 0.5 mg/L. Recovery from feed over the concentration range 2-6 g/kg was >96%.

High Performance Liquid Chromatographic Determination of Caffeine in Decaffeinated Coffee, Tea, and Beverage Products

1983 ◽  
Vol 66 (3) ◽  
pp. 606-609 ◽  
Author(s):  
Samy H Ashoor ◽  
George J Seperich ◽  
Woodrow C Monte ◽  
Jim Welty
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Uv Detector ◽  
Coefficients Of Variation ◽  
Decaffeinated Coffee ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method was developed for determining caffeine in decaffeinated coffee, tea, and beverage products by high performance liquid chromatography (HPLC). The HPLC system consisted of a Bio-Sil ODS-5S C18 column, methanol-water (25 + 75) mobile phase at 1 mL/min, and a UV detector. The method is simple and specific. Caffeine recoveries were 93.8-98.3% and coefficients of variation were 0.90-2.25%.

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