Rapid High Performance Liquid Chromatographic Determination of Monosodium Glutamate in Food

1982 ◽  
Vol 65 (3) ◽  
pp. 567-571
Author(s):  
Peter Sporns

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.

1982 ◽  
Vol 28 (10) ◽  
pp. 2143-2148 ◽  
Author(s):  
P M Edelbroek ◽  
E J de Haas ◽  
F A de Wolff

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.


1980 ◽  
Vol 26 (1) ◽  
pp. 117-119
Author(s):  
J O Miners ◽  
T Foenander ◽  
D J Birkett

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.


1980 ◽  
Vol 26 (1) ◽  
pp. 117-119 ◽  
Author(s):  
J O Miners ◽  
T Foenander ◽  
D J Birkett

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.


1981 ◽  
Vol 64 (4) ◽  
pp. 805-807
Author(s):  
Leslie G West ◽  
Marie A Llorente

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%.


1982 ◽  
Vol 65 (3) ◽  
pp. 706-710
Author(s):  
Aziz Geahchan ◽  
Paul Chambon ◽  
Pierre Genoux

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%.


1980 ◽  
Vol 63 (5) ◽  
pp. 1044-1048 ◽  
Author(s):  
Jean-Michel Wal ◽  
Jean-Claude Peleran ◽  
Georges F Bories

Abstract A rapid and sensitive high performance liquid chromatographic method for the determination of trace amounts of chloramphenicol (CP) in milk has been developed. The antibiotic can be quantitated at a 10 ppb level with a limit of detectability estimated at 5 ppb. Recoveries ranged from 72 to 99.5%. Milking studies have been carried out on goats that received CP either by intramuscular injection or by intramammary administration. CP was measured in milk samples collected 1, 2, 3, 4, 5, 6, 7, 8, 24, 32 h after treatments. No residue could be detected 32 h after treatment. No interfering peaks appeared on control milk chromatograms.


1986 ◽  
Vol 32 (7) ◽  
pp. 1311-1317 ◽  
Author(s):  
H F Proelss ◽  
T B Townsend

Abstract We report an isocratic "high-performance" liquid chromatographic method for the simultaneous measurement of tocainide, lidocaine, procainamide, quinidine, disopyramide, and their major active metabolites in serum. The drugs are extracted from 200 microL of serum at pH 9.5 with 1.5 mL of 1,2-dichloromethane, concentrated by evaporation, and separated on a CN-bonded-phase column at 40 degrees C (flow rate 2 mL/min) with a pH 7.1 mobile phase of acetonitrile/methanol/phosphate buffer (60/7/33, by vol); the phosphate buffer contains 10 mmol of KH2PO4 and 0.5 mmol of triethylamine per liter. The antiarrhythmic drugs elute in the K' (capacity factor) range of 1.43 (lidocaine) to 5.7 (disopyramide). Results vary linearly with drug concentration to at least 30 mg/L; the detection limit is 0.1-0.2 mg/L. Within-run precision (CV) ranges from 0.9% to 5.0% and day-to-day precision from 2.1% to 6.2%, depending on the specific drug and its concentration in serum. Extraction efficiencies vary from 76% to 85% and analytical recoveries from 98.5% to 103%. At toxic serum concentrations, several basic drugs may interfere with the assay of some antiarrhythmics, but only hydroxyzine, verapamil, and certain local anesthetics interfere at therapeutic concentrations.


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