Total Sugars as Invert in Animal Feed Products: Collaborative Study

1974 ◽  
Vol 57 (2) ◽  
pp. 382-386
Author(s):  
Howard P Moore ◽  
Dorothy Berg
Keyword(s):  
Standard Deviation ◽  
Coefficient Of Variation ◽  
Animal Feed ◽  
Sucrose Solution ◽  
Collaborative Study ◽  
Total Sugars ◽  
Average Recovery ◽  
Coefficients Of Variation ◽  
Standard Deviations

Abstract An expressed need for a method of analyzing for total sugars as invert in animal feed products led to a modification of the volumetric sugar method. Twenty collaborators, analyzing 3 pairs of samples of molasses products, plus a known concentration of sucrose and a sample of dried whey, produced results with standard deviations ranging from 1.25 to 1.86 and coefficients of variation ranging from 3.6 to 5.1. The average recovery of the known sucrose solution was 98 % with a standard deviation of 1.22 and a coefficient of variation of 2.9. The method has been adopted as official first action to replace sec. 7.058.

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.

Multiresidue Gas Chromatographic Method for Determining Organochlorine Pesticides in Meats: Validation Study for Swine and Beef Fats

1985 ◽  
Vol 68 (5) ◽  
pp. 941-944
Author(s):  
James A Ault ◽  
Timothy E Spurgeon ◽  
Douglas S Gillard ◽  
Edward T Mallinson
Keyword(s):  
Organochlorine Pesticides ◽  
Validation Study ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Heptachlor Epoxide ◽  
Average Recovery ◽  
Coefficients Of Variation ◽  
Poultry Fat ◽  
Gas Chromatographic Method

Abstract A validation of a previously studied method for determining organochlorine residues in poultry fat was conducted to extend the usefulness of the method to beef and swine fats. The validation samples consisted of 16 materials all analyzed in duplicate. Fortification levels ranged from 0.02 to 1.2 ppm for a-BHC, lindane, cis- and Irans-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 101 % with a range of 7 9 - 113%, not including toxaphene. The ranges of coefficients of variation wtreCV. = 0-23.37% and CVX = 3.74-26.19%. The results were comparable to the previous collaborative study of the same method for poultry fat. The extended method has been adopted official first action

scholarly journals Crude Fat, Hexanes Extraction, in Feed, Cereal Grain, and Forage (Randall/Soxtec/Submersion Method): Collaborative Study

2003 ◽  
Vol 86 (5) ◽  
pp. 899-908 ◽  
Author(s):  
Nancy J Thiex ◽  
Shirley Anderson ◽  
Bryan Gildemeister ◽  
W Adcock ◽  
J Boedigheimer ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Animal Feed ◽  
Collaborative Study ◽  
Meat Products ◽  
The United States ◽  
Official Method ◽  
Cereal Grain ◽  
Relative Standard ◽  
Time Required

Abstract A method for determining crude fat in animal feed, cereal grain, and forage (plant tissue) was collaboratively studied. Crude fat was extracted from the animal feed, cereal grain, or forage material with hexanes by the Randall method, also called the Soxtec method or the submersion method. The use of hexanes provides for an alternative to diethyl ether for fat extractions. The proposed submersion method considerably decreases the extraction time required to complete a batch of samples compared to Soxhlet. The increase in throughput is very desirable in the quest for faster turnaround times and the greater efficiency in the use of labor. In addition, this method provides for reclamation of the solvent as a step of the method. The submersion method for fat extraction was previously studied for meat and meat products and was accepted as AOAC Official Method 991.36. Fourteen blind samples were sent to 14 collaborators in the United States, Sweden, Canada, and Germany. The within-laboratory relative standard deviation (repeatability) ranged from 1.23 to 5.80% for crude fat. Among-laboratory (including within) relative standard deviation (reproducibility) ranged from 1.88 to 14.1%. The method is recommended for Official First Action.

scholarly journals Crude Fat, Diethyl Ether Extraction, in Feed, Cereal Grain, and Forage (Randall/Soxtec/Submersion Method): Collaborative Study

2003 ◽  
Vol 86 (5) ◽  
pp. 888-898 ◽  
Author(s):  
Nancy J Thiex ◽  
Shirley Anderson ◽  
Bryan Gildemeister ◽  
W Adcock ◽  
J Boedigheimer ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Diethyl Ether ◽  
Animal Feed ◽  
Collaborative Study ◽  
Meat Products ◽  
The United States ◽  
Official Method ◽  
Cereal Grain ◽  
Relative Standard

Abstract A method for determining crude fat in animal feed, cereal grain, and forage (plant tissue) was collaboratively studied. Crude fat was extracted from the animal feed, cereal grain, or forage material with diethyl ether by the Randall method, also called the Soxtec method or the submersion method. The proposed submersion method considerably decreases the extraction time required to complete a batch of samples. The increase in throughput is very desirable in the quest for faster turnaround times and the greater efficiency in the use of labor. In addition, this method provides for reclamation of the solvent as a step of the method. The submersion method for fat extraction was previously studied for meat and meat products and was accepted as AOAC Official Method 991.36. Fourteen blind samples were sent to 12 collaborators in the United States, Sweden, Canada, and Germany. The within-laboratory relative standard deviation (repeatability) ranged from 1.09 to 9.26% for crude fat. Among-laboratory (including within) relative standard deviation (reproducibility) ranged from 1.0 to 21.0%. The method is recommended for Official First Action.

Gas Chromatographic Methods for Determination of γ-BHC in Technical Emulsifiable Concentrates and Water-Dispersible Powder Formulations and in Lindane Shampoo and Lotion: Collaborative Study

1984 ◽  
Vol 67 (4) ◽  
pp. 834-837
Author(s):  
James W Miles ◽  
Dwight L Mount ◽  
◽  
T J Beckmann ◽  
S K Carrigan ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Internal Standard ◽  
The Other ◽  
Water Dispersible ◽  
Coefficients Of Variation ◽  
Aoac Method ◽  
Liquid Chromatographic ◽  
Gas Chromatographic Separation

Abstract Although the gas chromatographic separation of the isomers of BHC was demonstrated two decades ago, the present AOAC method of analysis of BHC for gamma-isomer (lindane) content is based on a separation carried out on a liquid chromatographic partition column. A method of analysis has been developed that uses an OV-210 column for separation of the gamma-isomer from the other isomers and impurities in technical BHC. Di-n-propyl phthalate was chosen as an internal standard. The same system allows quantitation of lindane in lotion and shampoo after these products are extracted with ethyl acetate-isooctane (1 + 4). The analytical methods were subjected to a collaborative trial with 10 laboratories. The coefficient of variation for technical BHC was 2.83%. For the water-dispersible powder and emulsifiable concentrate, the coefficients of variation were 2.89% and 4.62%, respectively. Coefficients of variation for 1% lindane lotion and shampoo were 4.36% and 11.92%, respectively. The method has been adopted official first action.

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.

Spectrophotometric Determination of Cyclamate in Soft Drinks and Desserts: Complementary Collaborative Study

1988 ◽  
Vol 71 (6) ◽  
pp. 1212-1214
Author(s):  
Anna-Maija K SJÖBERG
Keyword(s):  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Soft Drink ◽  
Collaborative Study ◽  
Soft Drinks ◽  
Food Control ◽  
Average Recovery ◽  
Relative Standard ◽  
Standard Deviations

Abstract Fifteen official food control laboratories participated in a collaborative study of a spectrophotometric method to determine cyclamate in a soft drink and a dessert at concentrations of 90-311 mg/L and 202-526 mg/kg, respectively, with blind duplicates and a blank. Average recovery from the soft drink was 97.5%, and from the dessert, 98.6%. Reproducibility relative standard deviations were 4.7-6.5% and 6.9-8.5%, respectively. The outlier percentage was 5.5%. This study complements an earlier work by leading Nordic food laboratories and was designed according to the latest recommendations. The results of this study were compared with those of the earlier collaborative study and with general collaborative results obtained by AOAC.

Analysis of Ochratoxins A and B and Their Esters in Barley, Using Partition and Thin Layer Chromatography. II. Collaborative Study

1973 ◽  
Vol 56 (4) ◽  
pp. 822-826
Author(s):  
Stanley Nesheim
Keyword(s):  
Thin Layer ◽  
Ochratoxin A ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Ethyl Esters ◽  
The Other ◽  
Average Recovery ◽  
Confirmation Test ◽  
Two Samples ◽  
Layer Chromatography

Abstract To test the method of Nesheim et al., 6 samples wert; analyzed in 13 laboratories. The samples encompassed a blank and 5 samples containing one or more ochratoxins in the range 50–200 μg/kg. Two samples were spiked with the 4 ochratoxin standards and 3 were spiked with barley naturally contaminated with ochratoxin A. The confirmation of identity of ochratoxins A and B by preparation of their ethyl ester derivatives was also tested. The average recovery of standard ochratoxin A was 112% at levels of 45 and 90 μg/kg, with a 27.1% coefficient of variation calculated from analysis of variance, one analyst, one replicate. Similar satisfactory results were obtained for the ethyl esters of A and B at a level of 120 μg/kg. The results were unsatisfactory for ochratoxin B and for the esters of A and B at the 60 μg/kg level. The chemical confirmation test was satisfactory for both ochratoxins A and B. The method, including chemical confirmation, has been adopted as official first action as quantitative for ochratoxin A and qualitative for the other toxins.

Dry Column-Thermal Energy Analyzer Method for Determining N-Nitrosopyrrolidine in Fried Bacon: Collaborative Study

1984 ◽  
Vol 67 (3) ◽  
pp. 521-525
Author(s):  
Walter Fiddler ◽  
John W Pensabene ◽  
Robert A Gates ◽  
John G Phillips ◽  
◽  
...  
Keyword(s):  
Thermal Energy ◽  
Collaborative Study ◽  
Internal Standard ◽  
Mineral Oil ◽  
Energy Analyzer ◽  
High Group ◽  
Average Recovery ◽  
Column Method ◽  
Coefficients Of Variation ◽  
Repeatability And Reproducibility

Abstract A dry column method for isolating N-nitrosopyrrolidine (NPYR) from fried, cure-pumped bacon and detection by gas chromatography-thermal energy analyzer (TEA) was studied collaboratively. Testing the results obtained from 11 collaborators for homogeneous variances among samples resulted in splitting the nonzero samples into 2 groups of sample levels, each with similar variances. Outlying results were identified by AOAC-recommended procedures, and laboratories having outliers within a group were excluded. Results from the 9 collaborators remaining in the low group yielded coefficients of variation (CV) of 6.00% and 7.47% for repeatability and reproducibility, respectively, and the 8 collaborators remaining in the high group yielded CV values of 5.64% and 13.72%, respectively. An 85.2% overall average recovery of the N-nitrosoazetidine internal standard was obtained with an average laboratory CV of 10.5%. The method has been adopted official first action as an alternative to the mineral oil distillation-TEA screening procedure.

Microbiological Assay of Neomycin in Feed: Collaborative Study

1970 ◽  
Vol 53 (1) ◽  
pp. 60-68
Author(s):  
A W Neff ◽  
C C Miller ◽  
A R Barbiers
Keyword(s):  
Standard Deviation ◽  
Random Sample ◽  
Soybean Meal ◽  
Collaborative Study ◽  
Microbiological Assay ◽  
Negative Bias ◽  
Average Recovery

Abstract Eighteen laboratories collaboratively studied a method for the assay of neomycin, involving six levels of fortification and four diverse types of feed. The average recovery was 95.5%, which included a feed high in soybean meal (65%) that resulted in a definite negative bias in recovery. After eliminating the results from this feed the average recovery became 100.3% with an estimated standard deviation of 15.2% for a random sample. It is recommended that the method be adopted as official first action.

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