Manual Determination of Minced Fish Flesh in Mixed Fillet-Minced Cod Blocks: Collaborative Study

1988 ◽  
Vol 71 (1) ◽  
pp. 38-40
Author(s):  
J Perry Lane ◽  
Robert J Learson ◽  
◽  
S Berube ◽  
N Farstad ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Rapid Method ◽  
Collaborative Study ◽  
Fish Flesh ◽  
Coefficients Of Variation ◽  
Minced Fish ◽  
Standard Deviations

Abstract A simple, rapid method for determining the amount of minced fish in mixed fillet-minced cod blocks was tested by 9 collaborators. Each collaborator first examined 2 practice blocks containing 20% mince, and then examined 6 blind duplicate samples of 5 lb cod blocks from each of 3 test lots containing, respectively, 26.25, 18.75, and 12.5% mince. The data from one of the 9 collaborators was not usable because of a malfunctioning scale. Standard deviations (SD) for the 3 lots (all 8 collaborators combined) were 1.77, 1.51, and 1.65, and coefficients of variation (CV) were 6.8, 8.9, and 16.2%, respectively. For comparison, the results of an informal collaborative study by 10 participants on 16.5 lb mixed cod blocks containing 20.1% mince were SD 2.72 and CV 0.136%. Collaborators reported no problems with the method, and statistical analysis shows the method to be sufficiently precise for this type of determination. The method has been adopted official first action for cod.

Determination of Zearalenone in Corn: Collaborative Study

1976 ◽  
Vol 59 (3) ◽  
pp. 666-670
Author(s):  
Odette L Shotwell ◽  
Marion L Goulden ◽  
Glenn A Bennett
Keyword(s):  
Statistical Analysis ◽  
Thin Layer ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Corn Sample ◽  
Yellow Corn ◽  
Coefficients Of Variation ◽  
The Mean

Abstract Corn samples spiked at levels of 100, 300, 1000, and 2000 μg zearalenone/kg were sent to 22 collaborators for analysis by the Eppley method. All samples were yellow corn except one white corn sample spiked at 2000 μg/kg. Results from 16 collaborators were statistically analyzed. Only 4 of 16 collaborators detected zearalenone in the sample containing 100 μg/kg, but 11 detected the toxin in the sample containing 300 μg/kg. Average recoveries from all samples were 129% at 300 μg/kg, 101% at 1000 μg/kg, and 88% at 2000 μg/kg. The between-laboratory coefficients of variation were 53.0% at 300 μg/kg, 38.2% at 1000 μg/kg, and 27.0% at 2000 μg/kg. Five naturally contaminated corn samples, one in triplicate, were also provided. The mean level of zearalenone in the naturally contaminated samples ranged from 431 to 7622 μg/kg. The mean coefficient of variation for all samples was 40.5%. Two collaborators measured quantities of zearalenone on thin layer chromatographic plates densitometrically. Their results were not included in the statistical analysis, but the results indicated that densitometric measurement, given proper dilutions of solutions, could be used. The method has been adopted as official first action.

Gas Chromatographic-Chemiluminescence Method for Determination of Volatile NNitrosamines in Minced Fish-Meat and Surimi-Meat Frankfurters: Collaborative Study

1990 ◽  
Vol 73 (6) ◽  
pp. 947-952
Author(s):  
John W Pensabene ◽  
Walter Fiddler ◽  
John G Phillips
Keyword(s):  
Extraction Method ◽  
Solid Phase ◽  
Collaborative Study ◽  
Energy Analyzer ◽  
Chemiluminescence Method ◽  
Fish Meat ◽  
Relative Standard ◽  
Minced Fish ◽  
Standard Deviations

Abstract A collaborative study was carried out on a solid-phase extraction method for separating volatile N-nltrosamlnes, particularly N-nltrosodlmethylamlne (NDMA), from combination minced fish or surlml-meat frankfurters with detection by gas chromatography-chemllumlnescence (thermal energy analyzer). The results from the 10 collaborators were evaluated using the most recent AOAC guidelines for determining outliers and for the analysis of variance. For NDMA, repeatability standard deviations, sr, ranged from 0.56 to 2.25; repeatability relative standard deviations, RSDr, ranged from 8.9 to 11.5%. Reproducibility standard deviations, sR, for NDMA ranged from 1.40 to 6.49, and reproducibility relative standard deviations, RSDR, ranged from 24.2 to 28.9%. Our data compared favorably to the reproducibility (RSDR) curve of Horwltz. The method has been adopted official first action by AOAC.

Chloroform-Methanol Extraction Method for Determination of Fat in Foods: Collaborative Study

1983 ◽  
Vol 66 (4) ◽  
pp. 927-932 ◽  
Author(s):  
Chester E Daugherty ◽  
Harry G Lento ◽  
◽  
M L Adams ◽  
E W Beckert ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Extraction Method ◽  
Collaborative Study ◽  
Fat Content ◽  
Processed Foods ◽  
Methanol Extraction ◽  
Complete Extraction ◽  
Standard Deviations ◽  
Chloroform Methanol

Abstract Achloroform-methanol extraction method (complete extraction of fat in 3 min) for determining fat in processed and prepared foods has been studied collaboratively. Fourteen collaborators reported single replicate fat results on 7 samples representative of various food types and 2 spiked samples by the proposed method. Each sample was accompanied by a blind duplicate. For statistical purposes, the blind duplicates were treated as paired observations, and there were 2 laboratory outliers. There was a 97.9% agreement among the results from the remaining 12 collaborators and the Associate Referee for the unfortified samples. Recoveries of 93.8 and 98.3% were obtained on fortified samples, based on results obtained from 11 collaborators. The statistical analysis of the results indicate (ranges for standard deviations were Sr = 0.083-0.528, Sb = 0.101-0.379, Sd = 8.130-0.631, for fat values ranging from 1.58 to 26.91%) that this method is adequate for quantitating the fat content in a wide variety of processed foods for nutritional labeling. The method has been adopted official first action.

Collaborative Study of the Determination of Dichlorophene in Veterinary Preparations by Ultraviolet Spectrophotometry

1972 ◽  
Vol 55 (1) ◽  
pp. 163-165
Author(s):  
Dalia M Gilvydis
Keyword(s):  
Standard Deviation ◽  
Collaborative Study ◽  
Liquid Extraction ◽  
Synthetic Mixture ◽  
Ultraviolet Spectrophotometry ◽  
Average Recovery ◽  
Liquid Liquid Extraction ◽  
Coefficients Of Variation ◽  
Standard Deviations

Abstract Dichlorophene is determined in veterinary preparations by a liquid-liquid extraction and UV quantitation. Eight collaborators each analyzed 4 commercial preparations and one synthetic mixture. The average recovery for dichlorophene in the synthetic mixture is 100.3% with a standard deviation of 2.13. The standard deviations obtained for the 5 samples range from 0.13 to 3.69 with coefficients of variation from 0.69 to 3.43. It is recommended that the method be adopted as official first action.

Collaborative Study of the Determination of Lead in Alkyd and Latex Paints

1974 ◽  
Vol 57 (3) ◽  
pp. 614-617
Author(s):  
Warren K Porter
Keyword(s):  
Statistical Analysis ◽  
Paint Film ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Acid Digestion ◽  
Absorption Spectrophotometry ◽  
Coefficients Of Variation ◽  
Nitric Acid Digestion ◽  
Minimal Bias

Abstract A collaborative study was conducted on the determination of lead in alkyd and latex paints by atomic absorption spectrophotometry after nitric acid digestion. Fourteen samples of blank paints and paints with known additions of lead were analyzed by 10 collaborators. Coefficients of variation from 4 to 16% were obtained for 0.33 to 0.02% lead in the paint solids. The statistical analysis indicates minimal bias and adequate precision for the analysis of lead in paints at the current regulatory limit (0.5% in the paint solids or dry paint film). The method has been adopted as official first action.

Differential Pulse Polarographic Determination of Iodine in Thyroid Tablets: Collaborative Study

1982 ◽  
Vol 65 (5) ◽  
pp. 1059-1062
Author(s):  
Walter Holak ◽  
◽  
R Baetz ◽  
P Beavin ◽  
P Gable ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Differential Pulse ◽  
Polarographic Determination ◽  
Coefficients Of Variation ◽  
Repeatability And Reproducibility ◽  
Standard Deviations ◽  
The U.S

Abstract A differential pulse polarographic (DPP) method for the determination of iodine in thyroid and thyroid preparations was collaboratively studied by 8 laboratories. The overall concentration of iodine in commercial thyroid tablets containing ¼, 1,2, and 5 gr. of declared thyroid was 0.196%. The overall repeatability and reproducibility standard deviations were 0.0043 and 0.0067, respectively, and the corresponding coefficients of variation were 2.18 and 3.41%, respectively. The results obtained by the DPP method agreed with those obtained by the U.S. Pharmacopeia XX method at the various concentrations of declared thyroid studied. The DPP method has been adopted official first action.

Proof Determination of Liqueurs and Alcoholic Dairy Products: Collaborative Study

1983 ◽  
Vol 66 (5) ◽  
pp. 1148-1151
Author(s):  
Duane H Strunk ◽  
Bertha M Timmel ◽  
Frances L Rapp ◽  
John C Aicken ◽  
◽  
...  
Keyword(s):  
Dairy Products ◽  
Ethanol Concentration ◽  
Collaborative Study ◽  
Dissolved Solids ◽  
Coefficients Of Variation ◽  
Sugar Mixtures ◽  
Standard Deviations

Abstract A method is described for determining the ethanol concentration of liqueur-type products containing dissolved solids. The sample is distilled in an allglass still equipped with spherical joints; the proof of the distillate, diluted to known volume, is measured by a Mettler/Paar density meter. Ten collaborators determined proof of 6 different synthetic liqueurs containing ethanol-water-sugar mixtures and 2 alcoholic dairy products. Proof of the samples varied from 33 to 92°. Standard deviations and coefficients of variation for this method varied from 0.069 to 0.278 and from 0.20° to 0.36°, respectively. The method has been adopted 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.

Collaborative Study of a Spectrophotometric Method for the Determination of Dienestrol in Pharmaceuticals

1973 ◽  
Vol 56 (3) ◽  
pp. 674-676
Author(s):  
Joseph H Graham
Keyword(s):  
Rapid Method ◽  
Spectrophotometric Method ◽  
Degradation Products ◽  
Collaborative Study ◽  
Partition Chromatography ◽  
Ultraviolet Spectrophotometry ◽  
Critical Step ◽  
Standard Deviations

Abstract A highly specific, sensitive, and rapid method for the determination of dienestrol was studied by 13 collaborators. Dienestrol is separated from excipient matter, degradation products, and other drugs present by column partition chromatography, converted to a substituted indene by acid-induced isomerization, and determined by ultraviolet spectrophotometry. Standard deviations obtained for the 4 samples used in the study, containing approximately 0.1 and 0.5 mg dienestrol, ranged from 1.81 to 3.04. The most critical step in the method is the use of suitable ether. This method has been adopted as official first action.

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.

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