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.

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.

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.

Determination of Iron in Alcoholic Beverages

1970 ◽  
Vol 53 (1) ◽  
pp. 12-16
Author(s):  
M K Meredith ◽  
Sidney Baldwin ◽  
A A Andreasen
Keyword(s):  
Atomic Absorption ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Atomic Absorption Spectrophotometry ◽  
Alcoholic Beverages ◽  
Wet Oxidation ◽  
Special Equipment ◽  
Oxidation Method ◽  
Trained Personnel

Abstract Results are presented for a collaborative study on the determination of ppm iron in alcoholic beverages, except beer, by the following methods: atomic absorption spectrophotometry, direct colorimetry using 2,4,6-tripyridyl-s-triazine (TPTZ) for alcoholic beverages other than brandy, and wet oxidation using sodium hypochlorite and hydrogen peroxide followed by color development with TPTZ for brandy only. When available, atomic absorption is the method of choice because of its speed and accuracy. The colorimetric method eliminates ashing, is relatively rapid, and does not require special equipment or highly trained personnel; however, it does not give accurate results for brandy. The wet oxidation method is satisfactory for brandy but requires more time, proper ventilation, and trained personnel. Results by these methods are accurate for routine determinations and it is recommended that the first two methods be adopted as official first action for the alcoholic products specified. Study on the wet oxidation method for products containing chelating agents and/or “complexed iron” should be continued.

Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

1990 ◽  
Vol 73 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Kurt Kolar
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Meat Products ◽  
Acid Oxidation ◽  
Colorimetric Determination ◽  
Mean Values ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

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.

Determination of Menthol in Cigarette Tobacco Filler

1967 ◽  
Vol 50 (4) ◽  
pp. 770-773
Author(s):  
Charles L Tucker ◽  
C L Ogg
Keyword(s):  
Chromatographic Method ◽  
Colorimetric Method ◽  
Cigarette Tobacco ◽  
Mean Values ◽  
Accuracy And Precision ◽  
Standard Deviations ◽  
Gas Chromatographic Method

Abstract A gas chromatographic and a colorimetric method for determining menthol in cigarette tobacco filler were studied collaboratively by 15 laboratories. No statistically significant differences were found in the precisions within or between laboratories. There were no significant differences between mean values for the two methods for any of the samples. Trends toward higher mean values for the colorimetric method and lower within-laboratory standard deviations for the gas chromatographic method were noted. Remarks by collaborators suggest that the accuracy and precision of the colorimetric method may be improved, and further studies are recommended.

Collaborative Study Using a ZDBT Colorimetric Method for the Determination of Copper in Alcoholic Products

1967 ◽  
Vol 50 (2) ◽  
pp. 334-338
Author(s):  
Duane H Strunk ◽  
A A Andreasen
Keyword(s):  
Sulfuric Acid ◽  
Carbon Tetrachloride ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Good Precision ◽  
Determination Of Copper

Abstract Results are given on a collaborative study in which a zinc dibenzyldithiocarbamate (ZDBT) colorimetric method is used to measure copper in alcoholic products such as high wine, spirits, gin, whisky, brandy, rum, and wine. In this method, the sample is made ca 0.SN with sulfuric acid, and carbon tetrachloride containing 0.2% ZDBT is added. The colored copper-ZDBT complex is extracted in the carbon tetrachloride and measured at 438 mμ against a similar carbon tetrachloride extract of a blank. Data show good precision, and it is recommended that the ZDBT method be adopted as official, first action.

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.

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.

Colorimetric Method for Ester Content of Alcoholic Beverages

1971 ◽  
Vol 54 (5) ◽  
pp. 1225-1230
Author(s):  
G R Coe ◽  
S Baldwin ◽  
A A Andreasen
Keyword(s):  
Alkaline Solution ◽  
Hydroxamic Acid ◽  
Colorimetric Method ◽  
Small Sample ◽  
Alcoholic Beverages ◽  
Colored Complex ◽  
Ester Content

Abstract A colorimetric method for determination of esters in alcoholic products was studied for the effect of procedural variables. It is based on the quantitative reaction of esters with hydroxylamine in alkaline solution to form a hydroxamic acid which, upon acidification, forms a colored complex in the presence of Fe(III) ions. Mathematical data are presented to demonstrate that the colorimetric method is superior to the AOAC saponification method, 9.051-9.052, for comparing samples which contain widely differing ester compositions. The colorimetric method is rapid and requires a small sample.

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