Liquid Chromatographic Determination of Dicloxacillin Preparations: Interlaboratoiy Study

1993 ◽  
Vol 76 (5) ◽  
pp. 1143-1145 ◽  
Author(s):  
Mei-Chich Hsu ◽  
Weng F Huang

Abstract A previously published liquid chromatographic method proposed for the analysis of dicloxacillin preparations was subjected to an interlaboratory study. The method is rigorously defined in terms of performance requirements, yet allows a degree of flexibility to the individual analyst. Eight laboratories participated in a study to analyze 3 samples in duplicate. Estimates for the repeatability and reproducibility of the method, expressed as relative standard deviations of the results of the determination of dicloxacillin preparations, were <0.57 and 2.56%, respectively.

1988 ◽  
Vol 71 (1) ◽  
pp. 36-37
Author(s):  
Ramesh J Trivedi

Abstract A simple, sensitive, and rapid liquid chromatographic method for quantitating α-ionone in toothpaste at levels of 20 ppm in the presence of large amounts of flavor has been developed. The method is accurate, precise, cost-effective, and specific for α-ionone. Average recovery of a laboratory-prepared sample was 99.0% with the relative standard deviation was 1.29% (n = 6).


1984 ◽  
Vol 67 (6) ◽  
pp. 1118-1120
Author(s):  
Ting Susan ◽  
◽  
R L Brown ◽  
L A Dougherty ◽  
J B Schepman ◽  
...  

Abstract A reverse phase liquid chromatographic method for the determination of methyldopa, methyldopa-hydrochlorothiazide, and methyldopachlorothiazide in tablets was collaboratively studied by 8 laboratories. Each collaborator received 20 samples that included drug substance, synthetic and commercial tablet compositions. The overall repeatability and reproducibility standard deviations for commercial tablets were 1.11 and 1.75% for methyldopa, 0.96 and 1.62% for chlorothiazide, and 1.21 and 2.15% for hydrochlorothiazide, respectively. The overall recoveries of methyldopa, chlorothiazide, and hydrochlorothiazide added to synthetic tablets were 100.78, 100.70, and 101.34%, respectively. The method has been adopted official first action.


2001 ◽  
Vol 84 (2) ◽  
pp. 493-497 ◽  
Author(s):  
Richard D Thompson ◽  
John T Quaife

Abstract A liquid chromatographic method was developed that provides a simple and rapid means of determining methyl anthranilate (MA) in carbonated and noncarbonated, artificial grape-flavored, nonalcoholic beverages. The proposed procedure, which was applied to 12 different products, uses a Nova-Pak C18 column, a mobile phase containing acetonitrile–0.025M KH2PO4 (40 + 60), pH 3.00, and UV detection at 220 nm. Assay values ranged from 0.35 to 16.6 Μg MA/mL. The intralaboratory precision (relative standard deviation) for the products ranged from 0.51 to 2.23% (n = 5), and recoveries via fortification ranged from 83.6 to 102.4%. The limits of quantitation and detection were 0.00417 and 0.00125 μg/mL, respectively, and the analyte response was linear over a 100-fold concentration range (0.0001–0.01 mg/mL).


1987 ◽  
Vol 70 (4) ◽  
pp. 689-691
Author(s):  
Abdel-Aziz M Wahbi ◽  
Mohammad A Abounassif ◽  
El-Rasheed A Gad-Kariem ◽  
Mahmoud W Ibrahim

Abstract A liquid chromatographic method for the individual determination of benzoic and cinnamic acids in 2 benzoin preparations is presented. The method specifies a reverse phase column and 0.01M KH2P04- methanol (85 + 15) as mobile phase at a flow rate of 1.8 mL/min, with detection at 254 nm. The method has been applied to 2 benzoin preparations and the results were compared with those from the British Pharmacopoeia method.


1989 ◽  
Vol 72 (2) ◽  
pp. 231-234 ◽  
Author(s):  
Mercedes Jalón ◽  
Majesús Peńa ◽  
Julián C Rivas

Abstract A reverse-phase liquid chromatographic method is described for the determination of carminic acid in yogurt. A C18 column is used with acetonitrile-1.19M formic acid (19 + 81) as mobile phase and diode array detection. Sample preparation includes deproteinization with papain and purification in a polyamide column. The relative standard deviation for repeated determinations of carminic acid in a commercial strawberry-flavored yogurt was 3.0%. Recoveries of carminic acid added to a natural-flavored yogurt ranged from 87.2 to 95.3% with a mean of 90.2%. The method permits measurement of amounts as low as 0.10 mg/kg.


1983 ◽  
Vol 66 (4) ◽  
pp. 909-912 ◽  
Author(s):  
Steven P Swanson ◽  
Venkatachalam Ramaswamy ◽  
Val R Beasley ◽  
William B Buck ◽  
Harold H Burmeister

Abstract The gas-liquid chromatographic method for the determination of T-2 toxin in plasma is described. The toxin is extracted with benzene, washed with aqueous sodium hydroxide, and chromatographed on a small Florisil column; the heptafluorobutyryl derivative is prepared by reaction with heptafluorobutyrylimidazole. The T-2 HFB derivative is chromatographed onOV-1 at 230°C and measured with an electron capture detector. Iso-T-2, an isomer of T-2 toxin, is added to samples as an internal standard before extraction. Recoveries averaged 98.0 ± 5.5% at levels ranging from 50 to 1000 ng/m L. The limit of detection is 25 ng/mL.


1988 ◽  
Vol 71 (5) ◽  
pp. 1046-1048
Author(s):  
Ada C Bello ◽  
Rita K Jhangiani

Abstract A liquid chromatographic method for the assay of morphine sulfate and some preservatives and impurities in the bulk drug and in injections has been developed and collaboratively studied in 8 laboratories. Each collaborator analyzed 5 samples: 1 bulk drug, 3 different concentrations of injectable dosages, and 1 prepared mixture containing, in addition to morphine sulfate, phenol, 2-mercaptobenzothiazole, and pseudomorphine. The proposed method quantitates morphine sulfate and resolves the other components for identification using a Clg reverse-phase column with a mobile solvent containing 240 mL methanol, 720 mL 0.005M 1-heptanesulfonic acid Na salt, and 10 mL acetic acid. Samples are prepared by direct dilution with mobile solvent minus 1-heptanesulfonic acid. All collaborators met system suitability requirements and performed the analysis without difficulty. No outliers were found when data were analyzed by the Dixon, Grubbs, double Grubbs, and Cochran tests. Relative standard deviations between laboratories (RSDR) for duplicate determinations of morphine sulfate ranged from 1.4 to 2.1%. Mean morphine sulfate recoveries for the bulk drug and the prepared mixture were 100.8 and 100.4%, respectively. The method has been approved interim official first action.


1997 ◽  
Vol 80 (3) ◽  
pp. 549-554 ◽  
Author(s):  
Karl-Erik Hellenás ◽  
Carina Branzell ◽  
H Poutanen ◽  
T Suortti ◽  
R Kaario ◽  
...  

Abstract Twelve laboratories participated in a collaborative study to evaluate precision parameters of a liquid chromatographic method for analysis of the glycoalkaloids α-solanine and α-chaconine in potato tubers. Samples consisted of frozen potato tuber homogenates distributed as 3 blind duplicates and 3 split-level pairs. The analytical method included aqueous extraction, workup on disposable solidphase extraction cartridges, and reversed-phase chromatography with photometric detection at 202 nm. Results for α-solanine and α-chaconine were received from 10 and 9 laboratories, respectively. Relative standard deviations for reproducibilo ity for α-solanine and α-chaconine were similar, ranging from 8 to 13% in the applied concentration range of 12 to 260 mg/kg fresh weight.


1984 ◽  
Vol 67 (3) ◽  
pp. 497-499
Author(s):  
Stephen C Slahck ◽  
◽  
J B Audino ◽  
O O Bennett ◽  
B D Folsom ◽  
...  

Abstract A liquid chromatographic method for the determination of propoxur in technical and formulated products has been subjected to a collaborative study with 8 participating collaborators. Formulations are extracted with acetonitrile and analyzed by reverse phase chromatography, with n-butyrophenone as an internal standard. Collaborators were furnished with samples of technical, 70% wettable powder, 1.5 emulsifiable, and 2% bait. Coefficient of variation values obtained on the 4 samples were 0.34, 0.68, 3.25, and 5.41%, respectively. The method has been adopted official first action.


1991 ◽  
Vol 74 (3) ◽  
pp. 487-493 ◽  
Author(s):  
Leon W Levan ◽  
Charlie J Barnes

Abstract A liquid chromatographic method for determination of thiabendazole, 5-hydroxythiabendazole, oxfendazole, mebendazole (MBZ), and fenbendazole (FBZ) In cattle liver and muscle was collaboratively studied in 7 laboratories In 1986. For blind fortified samples containing 800 ppb FBZ, average recovery and relative standard deviations for repeatability and reproducibility (RSDr and RSDR) based on results from 6 of the participating laboratories were 83%, 12.7%, and 14.0%, respectively. Recoveries of FBZ from incurred liver samples were more variable. Recoveries of MBZ from livers fortified at the 100 ppb level were encouraging; however, the drug levels were too low in the incurred samples used for MBZ studies. Except for FBZ and MBZ In liver, the study data were not satisfactory. The method has been adopted official first action by AOAC for determination of 800-1600 ppb fenbendazole In liver. The analysis should be repeated using a smaller sample size when Initial analyses show levels greater than 1600 ppb FBZ.


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