Collaborative Study of the Microanalytical Determination of Iodine by Oxygen Flask Combustion

1973 ◽  
Vol 56 (4) ◽  
pp. 888-891
Author(s):  
Roger A Lalancette ◽  
Al Steyermark ◽  
Donna M Lukaszewski ◽  
Patti L Kostrzewski
Keyword(s):  
Organic Compounds ◽  
Statistical Evaluation ◽  
Collaborative Study ◽  
Specific Method ◽  
Iodobenzoic Acid

Abstract Twenty-two collaborators participated in the study of a specific method using oxygen flask combustion followed by mercurimetric titration of the resulting iodide. With the exception of 2 collaborators, all obtained acceptable results on m-iodobenzoic acid. Statistical evaluation of the data from all collaborators gave: x̿ = 51.07%, x̿ – theory = –0.10%, s̄ = 0.28, and sm = 0.94. When the results of 2 collaborators are omitted, the corresponding values are: 51.07%, –0.10%, 0.15, and 0.19, respectively. Similar results were obtained on p-nitroiodobenzene. The results from all collaborators gave: x̿ = 50.82%, x̿ – theory = – 0.14%, s̄ = 0.19, and sm = 0.43. When the results of 3 collaborators are omitted, the values are: 50.87%, –0.09%, 0.14, and 0.23, respectively. The method has been adopted as official first action, as an alternative to the Carius method, for the determination of iodine in organic compounds.

Collaborative Study of the Microanalytical Determination of Bromine and Chlorine by Oxygen Flask Combustion

1974 ◽  
Vol 57 (1) ◽  
pp. 26-28
Author(s):  
Roger A Lalancette ◽  
Al Steyermark
Keyword(s):  
Organic Compounds ◽  
Statistical Evaluation ◽  
Collaborative Study ◽  
Specific Method ◽  
Acceptable Accuracy ◽  
Accuracy And Precision

Abstract Twenty collaborators studied a specific method for bromine and chlorine, using oxygen flask combustion followed by mercurimetric titration. The method was previously adopted as official first action for iodine in organic compounds. Eighty-four determinations were performed on p-bromoacetanilide for which the statistical evaluation of the data gave x = 37.30%, x—theory = —0.03%, s = 0.13, and sm = 0.18. With the exception of one collaborator (x—theory = —0.55%), all obtained acceptable accuracy and precision and only his accuracy was not acceptable. Statistical evaluation of the data for 85 determinations on p-chloroacetanilide gave x = 20.86%, x—theory = −0.04%, s = 0.11, and sm = 0.11. All collaborators obtained acceptable accuracy and precision. The official first action method for iodine has been adopted as official first action for bromine and chlorine as an alternative to the Carius method.

Collaborative Study of the Microanalytical Determination of Phosphorus in Organic Compounds

1976 ◽  
Vol 59 (4) ◽  
pp. 835-837
Author(s):  
Roger A Lalancette ◽  
Al Steyermark ◽  
Norbert C Cherapak
Keyword(s):  
Organic Compounds ◽  
Statistical Evaluation ◽  
Collaborative Study ◽  
Specific Method ◽  
Lanthanum Phosphate ◽  
Hydronium Ions

Abstract Seven collaborators studied a specific method for the determination of phosphorus, using wet combustion followed by acidimetric titration of the hydronium ions produced by the precipitation of lanthanum phosphate. Statistical evaluation of the data for 29 determinations on triphenylphosphine gave: x̿ = 11.55%, x̿ — theory = −0.26%, s̄ = 0.33, and sm = 0.37. Omitting the results of one collaborator gave, for 21 determinations: x̿ = 11.66%, x̿ — theory = −0.15%, s̄ = 0.18, and sm = 0.30. Evaluation of the data for 33 determinations on diphenylphosphinic acid gave: x̿ = 14.11%, x̿ − theory = −0.09%, s̄ = 0.40, and sm = 0.45. Omitting the results of the same collaborator mentioned above, for 25 determinations, gave: x̿ = 14.28%, x̿ — theory = + 0.08%, s̄ = 0.27, and sm = 0.08. Since the number of collaborators was small, the study will be continued to collect more data.

Collaborative Study of the Microanalytical Determination of Phosphorus in Organic Compounds

1973 ◽  
Vol 56 (4) ◽  
pp. 897-900
Author(s):  
Roger A Lalancette ◽  
Al Steyermark ◽  
Ruth Ann Lee ◽  
Donna M Lukaszewski
Keyword(s):  
Phosphoric Acid ◽  
Organic Compounds ◽  
Statistical Evaluation ◽  
Collaborative Study ◽  
Wet Digestion ◽  
Gravimetric Determination ◽  
Two Samples ◽  
Significant Difference

Abstract Sixteen collaborators participated in the study of the determination of phosphorus in organic compounds. Two samples were analyzed by the methods currently in use in the collaborators’ respective laboratories. Samples were combusted by oxygen flask, peroxide fusion, and wet digestion with acid(s). The resulting phosphoric acid was determined either gravimetrically, colorimetrically by the heteropoly blue method, or colorimetrically by the molybdenum yellow method. The various combustion methods were not compared, since there were not enough data to warrant this. The determinative steps were compared, but the data showed no significant difference in either precision or accuracy for any variation. A statistical evaluation of the data showed that the overall mean for the colorimetric heteropoly blue determination of triphenylphosphine (11.81% P) for 4 collaborators is 11.72%; for the colorimetric molybdenum yellow determination for 5 collaborators, 11.70%; and for the gravimetric determination for 3 collaborators, 11.93%. For phenylmethylphosphinic acid (19.97% P), the corresponding values are 19.64, 19.80, and 19.95%.

Collaborative Study of Microanalytical Determination of Bromine and Chlorine by Oxygen Flask Combustion

1972 ◽  
Vol 55 (4) ◽  
pp. 680-683 ◽  
Author(s):  
Al Steyermark ◽  
Roger A Lalaxcette ◽  
Elise M Contreras
Keyword(s):  
Standard Deviation ◽  
Organic Compounds ◽  
Collaborative Study ◽  
Specific Method

Abstract Twenty-six collaborators participated in the study of a specific method using oxygen flask combustion followed by mercurimetric titration of the ionic halide. With the exception of 3 collaborators, all obtained good results for bromine, although a fourth collaborator obtained borderline results. Including data from all collaborators gave: mean, 36.90%; mean–theory, -0.43%; standard deviation, 0.31; and standard deviation of the means, 1.59. Omitting results of 3 collaborators, the figures become: 37.36%, +0.03%, 0.20, and 0.20, respectively. Omitting results of 4 collaborators, the values become: 37.33%, 0.00%, 0.18, and 0.15, respectively. Similar results were obtained for chlorine. The results from all collaborators gave: mean, 20.76%; mean – theory, -0.14%; standard deviation, 0.18; and standard deviation of the means, 0.48. Omitting results of 3 collaborators (the same as those for bromine), the values are : 20.89%, -0.01%, 0.14, and 0.12, respectively. Omitting the results of a fourth collaborator was not considered necessary, because the results for chlorine were borderline, and including them still gave a good overall picture. The method was adopted as official first action as an alternative to the Carius method for the determination of bromine and chlorine in organic compounds.

GLC Determination of Methanol in Liquids: Collaborative Study

1971 ◽  
Vol 54 (3) ◽  
pp. 558-559
Author(s):  
Donald L Andersen
Keyword(s):  
Collaborative Study ◽  
Flame Ionization Detector ◽  
Specific Method ◽  
Gas Chromatograph ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Sample Dilution

Abstract A rapid, specific method for methanol in aqueous and nonaqueous liquids has been developed and studied collaboratively. The method involves sample dilution with dioxane to approximately 0.4% methanol and injection into a gas chromatograph fitted with a Porapak R column and a flame ionization detector. A collaborative study, with 7 collaborators each reporting on 6 test portions, showed coefficients of variation of 2.7, 2.1, 2.3, 4.2, 1.8, and 3.5. The method has been adopted as official first action.

Liquid Chromatographic Method for Determination of Cyhexatin in Technical and Formulated Products: Collaborative Study

1988 ◽  
Vol 71 (1) ◽  
pp. 26-28
Author(s):  
Stephen Lupan
Keyword(s):  
Statistical Evaluation ◽  
Collaborative Study ◽  
Internal Standard ◽  
Paired Samples ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Wettable Powder ◽  
Aoac Method ◽  
Liquid Chromatographic

Abstract Cyhexatin technical (95%), 25 and 50% wettable powders, and a 600 g/L suspension concentrate were analyzed by liquid chromatography in a collaborative study of the method. Paired samples of cyhexatin technical and the 3 formulations were extracted with a mixture of methanol-water-acetic acid (950 + 49 + 1) containing n-decylbenzene as internal standard. Components were separated on a Lichrosorb RP-18 column using methanol-water-HCl-NaCl (93 + 7 + 0.001M + 0.005M) at 2.0 mL/min, and then detected at 214 nm. Results were received from 18 of the 20 laboratories who agreed to participate in the study; 14 sets of data were suitable for statistical evaluation. Repeatability coefficients of variation (CV0 ranged from 0.46% for the 50% wettable powder to 1.14% for the suspension concentrate. Reproducibility coefficients of variation (CVX) ranged from 0.70 to 1.85% for the 4 types of samples. The method has been adopted official first action as a CIPAC-AOAC method.

Automated Colorimetric Determination of Phenylephrine Hydrochloride in Drug Formulations. II. Collaborative Study

1971 ◽  
Vol 54 (3) ◽  
pp. 600-602
Author(s):  
Michel Margosis
Keyword(s):  
Coefficient Of Variation ◽  
Statistical Evaluation ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Colorimetric Determination ◽  
Good Recovery ◽  
Drug Formulations ◽  
Phenylephrine Hydrochloride ◽  
Automated Method

Abstract The automated colorimetric method designed by Lane for the analysis of phenylephrine HCl in drug formulations has been submitted to a collaborative study. Five samples, including 2 with known interferences, were sent to 9 collaborators. The results were subjected to statistical evaluation. These show good recovery and a maximum interlaboratory coefficient of variation of 4.5%. The automated method as evaluated in this study has been adopted as official first action.

Collaborative Study of the Ultraviolet Spectrophotometric and Gas-Liquid Chromatographic Methods for the Determination of Trifluralin and Benefin in Formulations

1973 ◽  
Vol 56 (3) ◽  
pp. 567-571
Author(s):  
Larry G Hambleton
Keyword(s):  
Statistical Evaluation ◽  
Collaborative Study ◽  
Matched Pairs ◽  
Uv Spectrometry ◽  
Solid Carrier ◽  
Chromatographic Methods ◽  
Flame Ionization ◽  
Liquid Chromatographic

Abstract Fourteen collaborators participated in a study of an ultraviolet (UV) Spectrophotometric and a gas-liquid (GLC) method for the determination of trifluralin and benefin. In the UV method, trifluralin or benefin is extracted from the solid carrier or dissolved in n-hexane, if the formulation is liquid, purified by chromatography on Florisil, and determined by UV spectrometry at 376 nm. In the GLC method, the compound is extracted from the solid carrier or dissolved in acetone, if liquid, and determined by flame ionization GLC, using a column containing 5% DC-200 on 80–100 mesh Chromosorb W (HP). A statistical evaluation of the data by the technique of closely matched pairs is presented. The data show good correlation between the 2 methods and the methods seem to be reasonably accurate and precise. The ultraviolet and gas chromatographic methods have been adopted as official first action.

Collaborative Study of the Colorimetric Determination of Zirconium in Antiperspirant Aerosols

1977 ◽  
Vol 60 (3) ◽  
pp. 663-668
Author(s):  
Paul Beavin
Keyword(s):  
Statistical Evaluation ◽  
Collaborative Study ◽  
Colorimetric Determination ◽  
Fusion Procedure ◽  
Coefficients Of Variation ◽  
Zirconium Compounds ◽  
Insoluble Form ◽  
Standard Deviations ◽  
Insoluble Compounds

Abstract A previously published method for determining zirconium in antiperspirant aerosols was collaboratively studied by 7 laboratories. The method consists of 2 procedures: a rapid dilution procedure for soluble zirconium compounds or a lengthier fusion procedure for total zirconium (soluble and insoluble compounds), followed by colorimetric determination. The collaborators were asked to perform the following: Spiking materials representing 4 levels of soluble zirconium were added to weighed portions of a zirconium-free cream base concentrate and the portions were assayed by the dilution procedure. Spiking materials representing 4 levels of zirconium in either the soluble or the insoluble form (or as a mixture) were also added to portions of the same concentrate and these portions were assayed by the fusion procedure. They were also asked to concentrate and assay, by both procedures, 2 cans each of 2 commercial aerosol antiperspirants containing zirconyl hydroxychloride. The average per cent recoveries and standard deviations for spiked samples were 99.8–100.2 and 1.69–2.71, respectively, for soluble compounds determined by the dilution procedure, and 93.8–97.4 and 3.09–4.78, respectively, for soluble and/or insoluble compounds determined by the fusion procedure. The average per cent zirconium found by the dilution procedure in the 2 commercial aerosol products was 0.751 and 0.792, respectively, with coefficients of variation of 2.94 and 2.53%, respectively. Insufficient collaborative results were received for the fusion procedure for statistical evaluation. The dilution procedure has been adopted as official first action.

Gas-Liquid Chromatographic Determination of N-Octylbicycloheptene Dicarboximide: Collaborative Study

1980 ◽  
Vol 63 (1) ◽  
pp. 0128-0130
Author(s):  
Vernon J Meinen ◽  
◽  
J L Allen ◽  
J B Audino ◽  
W G Boyd ◽  
...  
Keyword(s):  
Systematic Error ◽  
Statistical Evaluation ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Matched Pair ◽  
Flame Ionization ◽  
F Factor ◽  
Technical Material ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic method for the quantitative determination of N-octylbicycloheptene dicarboximide (MGK® 264 Synergist) was collaboratively studied with technical material and 2 formulations. The samples are diluted with acetone and determined after gas chromatography on an OV-1 column by a flame ionization detector. A statistical evaluation of the matched pair technical samples indicates good agreement among collaborators. An evaluation of the F-factor did not indicate significant systematic error contributions. A statistical evaluation of results for the 2 formulations showed coefficients of variation of 1.25 and 0.97. An examination of the t-values showed no contribution to systematic error. The method has been adopted as official first action.

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