scholarly journals Liquid Chromatographic Determination of the Glycoalkaloids α-Solanine and α-Chaconine in Potato Tubers: NMKL Interlaboratory Study

1997 ◽  
Vol 80 (3) ◽  
pp. 549-554 ◽  
Author(s):  
Karl-Erik Hellenás ◽  
Carina Branzell ◽  
H Poutanen ◽  
T Suortti ◽  
R Kaario ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Potato Tubers ◽  
Photometric Detection ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

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.

Liquid Chromatographic Determination of Flurazepam Hydrochloride in Bulk Drug and Dosage Forms: Collaborative Study

1992 ◽  
Vol 75 (2) ◽  
pp. 240-244 ◽  
Author(s):  
Eileen S Bargo
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Photometric Detection ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Repeatability And Reproducibility ◽  
Bulk Drug ◽  
Liquid Chromatographic

Abstract Eleven laboratories collaboratively studied the liquid chromatographic method for determining flurazepam hydrochloride In capsules and bulk drug. The method uses an octadecylsllane reversed- phase column, a mobile phase of methanol- 1% ammonium acetate (80 + 20), and photometric detection at 239 nm. Each collaborator received 8 samples: powdered composites of 5 commercial capsule preparations, each as a blind duplicate pair, and 3 bulk drug samples (1 blind duplicate). The ranges of repeatability and reproducibility relative standard deviations were 0.93-2.46 and 2.42-3.86% for the capsule samples and 0.97 and 1.76-2.27% for the bulk drug samples, respectively. The method was adopted first action by AOAC International.

Liquid Chromatographic Determination of Diazepam in Tablets: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 545-546
Author(s):  
Michael Tsougros
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Photometric Detection ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
The Mean ◽  
Liquid Chromatographic

Abstract A stability indicating liquid chromatographic method for the determination of diazepam in tablets was collaboratively studied by 6 laboratories. The method uses a Cig reverse phase column, a methanolwater mobile phase, p-tolualdehyde as the internal standard, and photometric detection at 254 nm. The collaborators were supplied with a synthetic tablet powder and 3 commercial tablet samples. The mean recovery of diazepam from the synthetic tablet powder was 100.2%. For all samples analyzed, the coefficient of variation was < 1.5%. The method has been adopted official first action.

Liquid Chromatographic Determination of Morphine Sulfate and Some Contaminants in Injections and Bulk Drug Material: Collaborative Study

1988 ◽  
Vol 71 (5) ◽  
pp. 1046-1048
Author(s):  
Ada C Bello ◽  
Rita K Jhangiani
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Morphine Sulfate ◽  
System Suitability ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Bulk Drug ◽  
Liquid Chromatographic

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.

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

Liquid Chromatographic Determination of Saccharin in Beverages and Desserts: Complementary Collaborative Study

1988 ◽  
Vol 71 (6) ◽  
pp. 1210-1212 ◽  
Author(s):  
Anna-Maija K SjÖberg
Keyword(s):  
Concentration Level ◽  
Soft Drink ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Food Control ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A complementary collaborative study was conducted on a liquid chromatographic method for determination of saccharin in accordance with the latest international recommendations. One industrial and 6 official food control laboratories analyzed 3 samples of a juice, a soft drink, and a dessert at concentration levels of 26-90 mg/L, 33-73 mg/L, and 56-147 mg/kg, respectively. Blind duplicates and a blank were supplied for each type of material at each concentration level. The beverage was chromatographed directly and the dessert was extracted with ethanol before chromatography. Average recoveries were 95-107%. The reproducibility relative standard deviations were 6.4-7.3% for the juice, 9.2-20.6% for the soft drink, and 13.4-16.2% for the dessert. The outlier percentage was 14.3%. The results were compared with those of an earlier collaborative study by Nordic laboratories and with general collaborative results obtained by AOAC

scholarly journals Liquid Chromatographic Determination of Scopolamine, Hyoscyamine, and Phenobarbital in Tablets

1997 ◽  
Vol 80 (2) ◽  
pp. 331-334 ◽  
Author(s):  
Susan Ting
Keyword(s):  
Mobile Phase ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Scopolamine Hydrobromide ◽  
Acid Sodium Salt ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method using a reversed- phase C18 column and octanesulfonic acid sodium salt-methanol as the mobile phase was developed for the simultaneous determination of phenobarbi- tal, scopolamine, and hyoscyamine in tablets. The mixture of the 3 drugs was resolved in <8 min. Detector responses were linear for 10 μL injections of the following: scopolamine hydrobromide, 8.25-206.3 μg/mL; hyoscyamine sulfate, 15.01-750.76 μg/mL; and phenobarbital, 250-751 μg/mL. Recoveries from tablets were 100.8% for scopolamine hydrobromide, 100.1% for hyoscyamine sulfate, and 100.3% for phenobarbital. Replicate injections of scopolamine hydrobromide, hyoscyamine sulfate, and phenobarbital gave an overall relative standard deviation of <1.0% (n = 10). The method detected as little as 3.3 ng scopolamine hydrobromide.

Liquid Chromatographic Determination of Flucytosine in Capsules: Collaborative Study

1988 ◽  
Vol 71 (1) ◽  
pp. 33-35
Author(s):  
Donald Shostak ◽  
Clifford Klein ◽  
◽  
C Cappon ◽  
N Falcone ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Photometric Detection ◽  
Acid Sodium Salt ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
The Mean ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for the determination of flucytosine in capsules was collaboratively studied by 7 laboratories. The method uses a C18 reverse phase column, water-methanol-acetic acid mobile phase containing 1-octanesulfonic acid sodium salt, p-aminobenzoic acid as internal standard, and photometric detection at 285 nm. The mean recovery value (±SD) of flucytosine from a synthetic formulation representing capsules was 99.2 ± 1.72% (CV = 1.73%). Composited samples of 250 and 500 mg commercial capsules gave assay values of (mean ± SD) 103.17 ± 2.21 and 99.29 ± 1.29% of declared, respectively. CV values were 2.15 and 1.30%. Reproducibility and repeatability CVs were 2.19 and 1.50%, respectively, for the 250 mg capsules, and 1.34 and 0.63%, respectively, for the 500 mg capsules. The method has been adopted official first action.

scholarly journals Liquid Chromatographic Determination of S-Adenosyl-L-Methionine in Dietary Supplement Tablets

2002 ◽  
Vol 85 (4) ◽  
pp. 901-905 ◽  
Author(s):  
Joseph Ziqi Zhou ◽  
Ted Waszkuc ◽  
Spiro Garbis ◽  
Felicia Mohammed
Keyword(s):  
Dietary Supplement ◽  
Phosphate Buffer ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Ion Pair ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simple and reliable liquid chromatographic method was developed for the determination of S-adenosyl-L-methionine (SAM) in dietary supplement tablets. SAM in products was extracted with a phosphate buffer and separated from the mixture on a reversed-phase C8 column by ion-pair chromatography. A gradient mobile phase containing phosphate buffer, sodium octanesulfonate as the ion-pair reagent, and acetonitrile at a flow rate of 1.2 mL/min was used in the analysis. The UV detection wavelength was set at 257 nm. The calibration curve was linear over a range of 75–375 μg/mL for the SAM active ion with R2 = 0.9999. Replicate tests indicated good reproducibility of the method with a relative standard deviation of 0.9% (n = 8). The multiple extractions and recoveries from fortified products showed the high accuracy of the analysis. The use of the acidic buffer for SAM extraction and elution and the use of a fresh standard for each calibration to counteract the instability of the SAM compound significantly improved the accuracy of the method.

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

1994 ◽  
Vol 77 (2) ◽  
pp. 328-330
Author(s):  
Thomas M Schmitt
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Relative Standard ◽  
Before And After ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
The Mean ◽  
Liquid Chromatographic

Abstract An isocratic reversed-phase liquid chromatographic (LC) procedure for measuring bentazon in commercial herbicide products and aqueous formulations was collaboratively studied by 16 laboratories. Samples are dissolved in LC eluent [0.075M sodium acetate–methanol (60 + 40)] and analyzed by LC on a 30 cm × 3.9 mm octadecylsilyl column with detection by UV absorbance at 340 nm. The quantity of active ingredient is determined by comparing the mean response factor (RF) of the sample to the mean RF of standards injected just before and after each pair of sample injections. The average relative standard deviation (RSDR) for 3 formulations studied was 1.54%; the RSDR for a technical sample was 0.77%. The method has been adopted first action by AOAC INTERNATIONAL.

Continuous Flow and Liquid Chromatographic Determination of p-Toluenesulfonamide in Ice Cream: Interlaboratory Study

1993 ◽  
Vol 76 (3) ◽  
pp. 570-574 ◽  
Author(s):  
Paul R Beljaars ◽  
Remmelt Van Dijk ◽  
Arie Brands ◽  
◽  
M Anderegg ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Collaborative Study ◽  
Ice Cream ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract A collaborative study of the continuous flow (CF) and liquid chromatographic determination of p-toluenesulfonamide (p-TSA) in ice cream was conducted by the Project Group on Collaborative Studies (PCS) of the Inspectorate for Health Protection, Food Inspection Service, The Netherlands. The procedure involves extraction of samples with water followed by cleanup of the extracts by dialysis in the CF system. Dialysates are injected by using a loop injector (500 μL) on a reversed-phase octadecylsilane bonded-phase (C18) column, chromatographed with methanol-water (25 + 75, v/v) as mobile phase, and quantitated by fluorescence detection at 230 nm (excitation) and 295 nm (emission). Seven ice-cream samples containing 0-6.35 mg/kg p-TSA at 4 different levels (1 blank and 3 pairs of split-level samples) were singularly analyzed according to the proposed procedure by 11 laboratories. The data were analyzed by the International Union of Pure and Applied Chemistry/ International Organization for Standardization/ AOAC protocol for statistics. No Cochran and Grubbs outliers were found among the participants. For all samples analyzed, repeatability relative standard deviations (RSDr) varied from 2.08 to 3.67%, whereas the reproducibility relative standard deviations (RSDR) ranged from 7.79 to 11.68%. The average p-TSA values for the split levels 1,2, and 3 were 0.55, 1.02, and 4.44 mg p-TSA/kg, respectively, with mean recoveries ranging from 76 to 79% (overall recovery range for all levels, 63-101%). No false-positive results were reported for the blank sample, and no interference was encountered by the presence of vanilla in samples.

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