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 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 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.

Determination of Esters in Alcoholic Beverages

1972 ◽  
Vol 55 (3) ◽  
pp. 559-563
Author(s):  
G R Coe ◽  
S Baldwin ◽  
A A Andreasen
Keyword(s):  
Statistical Evaluation ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Alcoholic Beverages ◽  
Accuracy And Precision

Abstract Results are presented on a collaborative study comparing 2 methods for the determination of esters in distilled alcoholic beverages. A previously described colorimetric method was compared with the present official AOAC saponification method, 9.050–9.052. Statistical evaluation of the data shows that the 2 methods are comparable in accuracy and precision. The colorimetric method has been adopted as official first action as an alternative to 9.050–9.052 for the determination of esters in distilled alcoholic beverages.

Multiresidue Gas Chromatographic Method for Determining Organochlorine Pesticides in Poultry Fat: Collaborative Study

1984 ◽  
Vol 67 (2) ◽  
pp. 284-289 ◽  
Author(s):  
James A Ault ◽  
Tim E Spurgeon ◽  
◽  
M M Anderson ◽  
R Bowers ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Gel Permeation Chromatography ◽  
Accuracy And Precision ◽  
Coefficients Of Variation ◽  
Poultry Fat ◽  
Gel Permeation ◽  
Detector Method ◽  
Gas Chromatographic Method

Abstract A gas chromatographic electron capture detector method is described for the quantitative determination of organochlorine pesticide residues in poultry fat. The samples are rendered and cleaned up using automated gel permeation chromatography. The collaborative samples consisted of 10 fortified samples and one incurred residue sample, all in duplicate. Fortification levels ranged from 0.15 to 1.0 ppm for a-BHC, lindane, cis- and frans-chlordane, octachlor epoxide, o,p' and p,p'-DDT, p,p'-DDE, p,p'-TDE, hexachlorobenzene, heptachlor epoxide, dieldrin, endrin, methoxychlor, mirex, and toxaphene. The average recovery was 91.9% with a range of 81-102%. The ranges of coefficients of variation were: CVo = 3.39-14.79%; CVL = 0-16.6%; and CVx = 5.82-19.0%. The results indicate accuracy and precision comparable to other official methodology. The method has been adopted official first action.

scholarly journals Determination of N-Octyl Bicycloheptene Dicarboximide, Pyrethrins, and Butylcarbityl 6-Propylpiperonyl Ether in Technical Materials, Concentrates, and Finished Products by Capillary Gas Chromatography: Collaborative Study

1998 ◽  
Vol 81 (3) ◽  
pp. 503-512 ◽  
Author(s):  
Khanh T Nguyen ◽  
Richard Moorman ◽  
Virginia Kuykendall ◽  
◽  
L Bura ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Collaborative Study ◽  
Piperonyl Butoxide ◽  
Capillary Gc ◽  
Split Injection ◽  
Flame Ionization ◽  
Accuracy And Precision ◽  
Insecticidal Compounds

abstract Nineteen collaborating laboratories (including the authors') analyzed 6 blind, duplicate pairs of various technical materials, pyrethrum extracts, concentrates, and finished products by split injection capillary gas chromatography (GC) with flame ionization detection. This procedure simultaneously quantitates with speed, ease, accuracy, and precision all 6 insecticidal compounds in pyrethrum: pyrethrin I, jasmolin I, cinerin I, pyrethrin II, jasmolin II, and cinerin II, as well as butylcarbityl 6-propylpiperonyl ether (BPE, the predominant compound in technical piperonyl butoxide, also commonly known as piperonyl butoxide) and both the endo and exo isomers of N-octyl bicycloheptene dicarboximide (MGK 264). Repeatability ranged from 4.28 to 7.22% for total pyrethrins, from 2.41 to 7.04% for BPE, and from 2.20 to 4.91 % for total MGK 264. Reproducibility ranged from 5.22 to 9.71 % for total pyrethrins, from 4.37 to 7.04% for BPE, and from 2.66 to 6.01 % for total MGK 264. The capillary GC method for these insecticidal compounds in technical materials, concentrates, and finished products has been adopted first action by AOAC INTERNATIONAL.

Comparison of Methods for Determining Sodium in Fertilizers

1981 ◽  
Vol 64 (3) ◽  
pp. 704-708
Author(s):  
Luis F Corominas ◽  
Víctor M Boy ◽  
Pedro Rojas
Keyword(s):  
Phosphate Rock ◽  
Collaborative Study ◽  
Ammonium Oxalate ◽  
Selective Electrode ◽  
Accuracy And Precision ◽  
Flame Emission ◽  
Aoac Method ◽  
Aoac Official ◽  
Aas Method

Abstract The AOAC official first action method, 2.147-2.150, for flame emission spectrophotometry (FES) determination of sodium in fertilizers was compared with the atomic absorption spectrophotometric (AAS) method and the sodium selective electrode (SSE) method. Ammonium oxalate, which was previously compared with water, H2SO4, HC1, and HNO3, was used to extract the sample for all 3 methods. Three synthetic NPK samples, 3 commercial samples (urea, normal superphosphate, and neutrophos), 1 phosphate rock, and 2 Magruder check samples were used for the study. Statistically significant differences were obtained in averages for most of the samples, but few differences were found in standard deviations. The AAS method showed the best accuracy and precision. Accuracy of the AOAC method is acceptable. The SSE method showed the highest deviations from the theoretical values. A collaborative study is recommended to compare the AOAC with the AAS method.

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.

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