Collaborative Study of the GLC Determination of Glycerine and Propylene Glycol in Tobacco

1969 ◽  
Vol 52 (4) ◽  
pp. 753-756
Author(s):  
J A Giles ◽  
R H Cundiff
Keyword(s):  
Gas Chromatography ◽  
Systematic Error ◽  
Propylene Glycol ◽  
Standard Method ◽  
Collaborative Study ◽  
Standard Deviations

Abstract A method for the methanolic extraction of glycerine and propylene glycol from tobacco and their determination by gas chromatography was collaboratively studied by 11 laboratories. Results show unacceptably high systematic error standard deviations. Additional study and refinement of the procedure will be required before it is suitable as a standard method.

Collaborative Study of the Official AOAC Flame Photometric Method for the Determination of Sodium in Fertilizers

1972 ◽  
Vol 55 (5) ◽  
pp. 986-988
Author(s):  
Luis F Corominas
Keyword(s):  
Ion Exchange ◽  
Systematic Error ◽  
Collaborative Study ◽  
Flame Photometry ◽  
Photometric Method ◽  
Standard Deviations

Abstract The present official final action method, 2.132–2.135 (11 th Ed.), has been compared with the 10th Edition method, 2.117–2.120; the need for ion exchange cleanup before flame photometry was also studied for samples containing 0.1-0.7% sodium. In general, the 11th Edition method produced more precise results; elimination of ion exchange treatment improved values obtained for the standard deviations of the systematic error. These findings are based on 600 individual results reported by 9 laboratories for 4 samples.

Collaborative Study of the Gas Chromatographic Determination of Six Thiocarbamate Herbicides in Formulations

1974 ◽  
Vol 57 (1) ◽  
pp. 53-59
Author(s):  
James E Barney
Keyword(s):  
Gas Chromatography ◽  
Systematic Error ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Flame Ionization Detector ◽  
Ionization Detector ◽  
Flame Ionization

Abstract Eptam, Ordram, Ro-Neet, Sutan, Tillam, and Vernam thiocarbamate herbicides are determined in emulsifiable and granular formulations by gas chromatography on an OV-1, SE-30, or OV-17 column with a flame ionization detector. Another thiocarbamate is used as an internal standard. The method was tested collaboratively by 19 laboratories, 18 of which tested the method on all 6 thiocarbamates. The coefficient of variation for 12 formulations was 3.10%. A significant amount of systematic error was detected, particularly in the analysis of emulsifiable formulations. The method has been adopted as official first action, and it is recommended that additional studies be conducted.

Karl Fischer Determination of Moisture in Soft-Moist Pet Foods: Collaborative Study

1990 ◽  
Vol 73 (3) ◽  
pp. 399-400 ◽  
Author(s):  
Roy E Schulze
Keyword(s):  
Propylene Glycol ◽  
Collaborative Study ◽  
Vacuum Drying ◽  
Volatile Components ◽  
Karl Fischer ◽  
Karl Fischer Method ◽  
Relative Standard ◽  
Standard Deviations ◽  
Fischer Method

Abstract Twelve collaborators participated in a study of a Karl Fischer method for determination of moisture in soft-moist, commercially available pet foods. The method avoids the erroneous high results noted In other methods (vacuum drying, toluene distillation, and drying at 135°C) when volatile components other than moisture, such as propylene glycol, are present. The standard deviations for repeatability (sr) and reproducibility (sR) were 0.3 and 0.4, respectively. The corresponding relative standard deviations (RSDr and RSDR) were 1.1 and 1.7%, respectively. The method has been approved interim official first action by AOAC.

Collaborative Study of the Spectrophotometric Determination of Procainamide Hydrochloride

1976 ◽  
Vol 59 (4) ◽  
pp. 807-810
Author(s):  
Jeffrey C Hamm
Keyword(s):  
Sodium Hydroxide ◽  
Acid Medium ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Collaborative Study ◽  
Dosage Forms ◽  
Standard Deviations

Abstract The USP analysis for procainamide HCl is titrimetric and relatively nonspecific, capsule and tablet dyes may interfere, and the method is not applicable to coated tablets. In the spectrophotofluorometric method the sample deteriorates when exposed to a xenon source. In the ultraviolet spectrophotometric method reported here, the sample is dispersed in acid medium, possible interferences are extracted in chloroform, base is added, procainamide is extracted in chloroform, the residue is dissolved in sodium hydroxide, and the compound is measured by absorption at 272 nm and comparison with a standard. Recoveries of standards added to capsule, tablet, and injection composites ranged from 99.3 to 102%. Twelve collaborators reported duplicate assay results for all 3 dosage forms with per cent standard deviations for 5 samples ranging from 1.01 to 1.27%. The method has been adopted as official first action.

Quantitative Ultraviolet Determination of Amiben in Dry Granular and Liquid Formulations: Collaborative Study

1970 ◽  
Vol 53 (6) ◽  
pp. 1155-1159
Author(s):  
Joax W Brunstad
Keyword(s):  
Sodium Salt ◽  
Collaborative Study ◽  
Standard Deviations

Abstract Amiben is determined as the sodium salt in 1% NaOH at 297 nm. Prepared materials and technical formulations containing 0-60 μg amiben/ml were analyzed in a collaborative study. Standard deviations for technical samples ranged from 0.05 to 0.45 and for prepared samples from 0.02 to 0.35. The method is recommended for adoption as official first action.

Colorimetric Determination of the Progestational Steroids in Contraceptive Tablets

1970 ◽  
Vol 53 (4) ◽  
pp. 831-833
Author(s):  
John Y P Wu
Keyword(s):  
Oral Contraceptive ◽  
Medroxyprogesterone Acetate ◽  
Collaborative Study ◽  
Chloroform Extract ◽  
Colorimetric Determination ◽  
Standard Deviations ◽  
Isonicotinyl Hydrazide ◽  
Norethindrone Acetate

Abstract Norethindrone, norethindrone acetate, dimethisterone, medroxyprogesterone acetate, and norethynodrel are determined in oral contraceptive tablets. For the first 4 compounds, a chloroform extract of the tablets is treated directly with isonicotinyl hydrazide reagent to produce a stable color which is measured at 380 nm. The chloroform extract of norethynodrel tablets is isomerized before the reagent is added. An intralaboratory study gave good results, with standard deviations of 0.74 to 1.21%. A collaborative study is recommended.

Collaborative Study of the Gas-Liquid Chromatographic Method for Determination of Stereochemical Composition of Amphetamine

1972 ◽  
Vol 55 (1) ◽  
pp. 146-148
Author(s):  
Clyde E Wells
Keyword(s):  
Column Chromatography ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Good Precision ◽  
Liquid Chromatographic Method ◽  
Precision And Accuracy ◽  
Standard Deviations ◽  
Liquid Chromatographic ◽  
Amphetamine Sulfate

Abstract Eight laboratories collaboratively studied a method for the quantitative GLC determination of d- and l-amphetamine in tablets. The drugs are separated from tablet excipients by column chromatography and reacted with Ntrifluoroacetyl-( 0-prolyl chloride, and the resulting derivatives are analyzed by GLC. The samples consisted of commercial d-amphetamine sulfate tablets (with and without butabarbital), dl-amphetamine sulfate tablets, and a mixed d- and l-amphetamine sulfate standard. Recoveries were acceptable, and the standard deviations never exceeded 0.64%. The results demonstrate that the method gives good precision and accuracy, and the method is recommended for adoption as official first action.

scholarly journals Repeatability and Reproducibility of Germicide Tests: A Literature Review

1999 ◽  
Vol 82 (2) ◽  
pp. 384-389 ◽  
Author(s):  
Nicola Tilt ◽  
Martin A Hamilton
Keyword(s):  
Literature Review ◽  
Standard Method ◽  
Collaborative Study ◽  
Hard Surface ◽  
Log Reduction ◽  
Repeatability And Reproducibility ◽  
Standard Deviations ◽  
Antimicrobial Assay

Abstract The results of a quantitative antimicrobial assay can be summarized by the log reduction value. For an assay to be proposed as a standard method, it is usually necessary to conduct a collaborative study to demonstrate that the repeatability and reproducibility standard deviations (SDs) of the log reduction values are sufficiently small. It is not clear, however, precisely how small those SDs should be. This paper describes the results of a literature review conducted to determine the range of repeatability and reproducibility SDs for standard quantitative antimicrobial assays. The underlying premise is that, for an assay to have been accepted as a standard method, its repeatability and reproducibility SDs must have been sufficiently small. This premise implies that the repeatability and reproducibility SDs of standard assays establish de facto guidelines for acceptability. The survey comprised papers where the SDs could be extracted directly or where they could be calculated from accessible data. Papers describing suspension tests as well as hard surface tests were included. For the standard antimicrobial assays reviewed, repeatability SDs ranged from 0.25 to 1.21 and the reproducibility SDs ranged from 0.31 to 1.54.

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