Semiautomated Method for Riboflavin in Food Products: Collaborative Study

1979 ◽  
Vol 62 (5) ◽  
pp. 1041-1044
Author(s):  
David C Egberg
Keyword(s):  
Collaborative Study ◽  
Food Products ◽  
Manual Method ◽  
Semiautomated Method

Abstract A collaborative study was conducted comparing a semiautomated riboflavin method with a manual riboflavin method for 10 food products. Six laboratories provided results from the semiautomated method and 16 laboratories used the manual technique. The semiautomated method was more repeatable within a laboratory and more reproducible between laboratories than was the manual method. The semiautomated method results compared favorably with the manual method for all 10 products.

Semiautomated Fluorometric Method for Determination of Vitamin C in Foods: Collaborative Study

1983 ◽  
Vol 66 (6) ◽  
pp. 1371-1377
Author(s):  
Jonathan W DeVries ◽  
◽  
P W Defibaugh ◽  
D Dunmire ◽  
F Ebert ◽  
...  
Keyword(s):  
Vitamin C ◽  
Continuous Flow ◽  
Collaborative Study ◽  
Fluorometric Method ◽  
Manual Method ◽  
Relative Standard ◽  
Sensitivity Specificity ◽  
The Cost ◽  
Semiautomated Method

Abstract Continuous flow automation of the microfluorometric procedure compares favorably with the manual method in sensitivity, specificity, and generality, and reduces the cost of routine vitamin C assay. Fifteen samples of 12 different products of ready-to-eat cereals, fruit juices, and infant formula were sent to 6 collaborators; one sample in each category was sent as blind duplicates. The within-laboratory standard deviations for 5 collaborators on the 3 sets of blind duplicates were 1.23, 0.87, and 3.64 mg/100 g, respectively. Overall, the average relative standard deviation between laboratories was 11.1% (range 4.5-16.6%) for the manual method and 4.99% (range 1.5-12.6%) for the semiautomated method. The method has been adopted official first action.

Semiautomated Method for Niacin and Niacinamide in Food Products: Collaborative Study

1979 ◽  
Vol 62 (5) ◽  
pp. 1027-1030
Author(s):  
David C Egberg
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Food Products ◽  
The Other ◽  
Microbiological Method ◽  
Semiautomated Method

Abstract collaborative study was conducted comparing a semiautomated colorimetric niacin method with a manual colorimetric and a microbiological method for 10 food products. Seven laboratories used the microbiological method, 7 laboratories used the manual colorimetric method, and 6 laboratories used the semiautomated method. The semiautomated method was more repeatable within a laboratory and more reproducible between laboratories than was either of the other methods. The semiautomated method results compared favorably with both the microbiological and manual colorimetric method results.

Collaborative Study of a Semiautomated Fluorometric Method for the Determination of Reserpine in Tablets

1976 ◽  
Vol 59 (2) ◽  
pp. 289-292
Author(s):  
Mary A Kreienbaum
Keyword(s):  
Vanadium Pentoxide ◽  
Collaborative Study ◽  
Dosage Level ◽  
Fluorometric Method ◽  
Coefficients Of Variation ◽  
Semiautomated Method

Abstract A semiautomated fluorometric method for the determination of resperpine in tablets was collaboratively studied by 7 laboratories. The method is a modification of the semiautomated method of Urbányi and Stober, which involves formation of a fluorogen with vanadium pentoxide. Collaborators were supplied with 3 composites, each from a different dosage level of commercial tablets. The results obtained agreed well with the AOAC manual fluorometric method; coefficients of variation ranged from 0.45 to 2.70%. The method has been adopted as official first action.

Proposed Method for Isolating Coagulase-Positive Staphylococci from Food Products: Report of a Collaborative Study

1966 ◽  
Vol 49 (2) ◽  
pp. 270-273
Author(s):  
Edward F Baer
Keyword(s):  
Statistical Analysis ◽  
Collaborative Study ◽  
Food Products ◽  
Coagulase Positive Staphylococci

Abstract Eleven collaborators studied the reproducibility of the method, proposed in 1965, for the isolation of coagulase-positive staphylococci. Samples studied were milk, beef and turkey samples, and fresh, headless shrimp. Based upon statistical analysis of collaborative results, the laboratory means did not vary significantly. The method is recommended for adoption as official, first action.

Dry Rehydratable Films for Enumeration of Coliforms and Aerobic Bacteria in Dairy Products: Collaborative Study

1989 ◽  
Vol 72 (2) ◽  
pp. 312-318
Author(s):  
Michael S Curiale ◽  
Paul Fahey ◽  
Terrance L Fox ◽  
J Sue Mcallister
Keyword(s):  
Dairy Products ◽  
Collaborative Study ◽  
Ice Cream ◽  
Food Products ◽  
Aerobic Bacteria ◽  
Chocolate Milk ◽  
Coliform Count ◽  
Dry Milk ◽  
Better Than ◽  
Dry Film

Abstract A collaborative study was conducted to compare proposed dry-film plating methods, using aerobic count plates and coliform count plates, to standard agar plating methods for quantifying aerobic bacteria and coliforms in dairy products. In this study, 5 food products (chocolate milk, pasteurized cheese, nonfat dry milk, evaporated milk, and vanilla ice cream), selected as representative dairy products, were analyzed by 11 collaborating laboratories. The results indicate that the dry-film plating methods are equivalent to or better than the agar plating methods. The aerobic count and coliform count dry-film plating methods have been adopted official first action.

Collaborative Study of a Semiautomated Method for the Analysis of Prednisolone and Prednisone Tablets

1977 ◽  
Vol 60 (1) ◽  
pp. 27-31
Author(s):  
James F Brower
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Alcoholic Solution ◽  
Tetramethylammonium Hydroxide ◽  
Assay Method ◽  
Blue Tetrazolium ◽  
Coefficients Of Variation ◽  
The Individual ◽  
Semiautomated Method

Abstract A semiautomated colorimetric method for the determination of prednisolone and prednisone was collaboratively studied by 6 collaborators. In the method, an alcoholic solution of the drug is extracted with chloroform and the extract is reacted with tetramethylammonium hydroxide and blue tetrazolium; the absorbance of the resulting color is read at 525 nm. Collaborators were supplied with 4 composites of tablets of different dosage levels, 2 containing prednisolone and 2 containing prednisone. Results agreed with those obtained by the author using the CSP total steroid assay method. The coefficients of variation of the individual collaborator’s results for prednisolone and prednisone ranged from 0.54 to 2.38 and from 0.34 to 2.19%, respectively. This method has been adopted as official first action.

Comparison of Semiautomated and Manual Methods for the Determination of Thiamine in Baby Cereals and Infant and Dietary Formulas

1977 ◽  
Vol 60 (3) ◽  
pp. 737-738
Author(s):  
Wallace M Ribbron ◽  
Kenneth E Stevenson ◽  
James R Kirk
Keyword(s):  
Manual Method ◽  
Standard Curve ◽  
Thiamine Content ◽  
Manual Methods ◽  
The Mean ◽  
Semiautomated Method

Abstract Using a semiautomated method, the mean thiamine content of specific products ranged from 88 to 101% and 83 to 93% for baby cereals and infant and dietary formulas, respectively, of those obtained with the AOAC manual method. The best results were obtained when data for the semiautomated method were calculated from a standard curve obtained by using thiamine solutions which had been digested and hydrolyzed along with the samples.

Semiautomated Method for the Analysis of Chlorpheniramine Maleate Tablets: Collaborative Study

1979 ◽  
Vol 62 (6) ◽  
pp. 1197-1201
Author(s):  
Ross D Kirchhoefer ◽  
◽  
R L Brown ◽  
J P Gleason ◽  
S Hauser ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Excellent Agreement ◽  
Active Ingredient ◽  
Close Agreement ◽  
Collaborative Study ◽  
Chlorpheniramine Maleate ◽  
Acidic Aqueous Solution ◽  
Coefficients Of Variation ◽  
Semiautomated Method

Abstract A semiautomated method for the analysis of chlorpheniramine maleate tablets, which is based on the USP XIX general assay for salts of organic nitrogenous bases, was collaboratively studied by 6 laboratories. Collaborators were supplied with 4 composites from 4 manufacturers. In the method, the active ingredient is dissolved in dilute HC1, sampled, made basic with dilute NaOH, and extracted with isooctane. The isooctane phase is resampled and the drug is re-extracted into dilute HCL. The absorbance of the acidic aqueous solution is measured at 265 nm. The Associate Referee assayed the collaborative samples to compare the semiautomated and USP XIX methods, and found close agreement in the results from the 2 methods. In the collaborative study of the semiautomated method, there was excellent agreement of the results obtained by the collaborators. The coefficients of variation ranged from 0.46 to 2.24%. The method has been adopted as official first action.

On-Line Generation of Cyanogen Chloride in Semiautomated Determination of Niacin and Niacinamide in Food Products

1986 ◽  
Vol 69 (3) ◽  
pp. 560-562
Author(s):  
Hoon Ge ◽  
Gary N Oman ◽  
Frank J Ebert
Keyword(s):  
Potassium Cyanide ◽  
Food Products ◽  
Cyanogen Chloride ◽  
Significant Difference ◽  
On Line ◽  
Chloramine T ◽  
Semiautomated Method ◽  
Paired T Test

Abstract The current AOAC procedure for semiautomated determination of niacin specifies the use of externally generated cyanogen bromide. Because of the safety concerns in handling this material, we investigated the use of an alternative system of generating cyanogen chloride in situ, using chloramine-T and potassium cyanide. Recovery studies conducted on 9 different food products yielded average recoveries of 101 %. A repeatability study resulted in a measured coefficient of variation of 2.9%. The AOAC niacin method was compared with this semiautomated method; 115 paired analyses on 8 different food types over 6 separate analytical replications indicated no significant difference by a paired t-test at the 95% confidence level.

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