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.

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 Method for the Rapid Determination of Protein in Meats Using the CEM Sprint™ Protein Analyzer: Collaborative Study

2011 ◽  
Vol 94 (5) ◽  
pp. 1555-1561
Author(s):  
Cindy Moser ◽  
Kathy Herman ◽  
K Barnhardt ◽  
M Ceizyk ◽  
T Chriscoe ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Rapid Determination ◽  
Collaborative Study ◽  
Meat Products ◽  
The United States ◽  
Processed Meat ◽  
Binding Agent ◽  
Relative Standard ◽  
Dye Binding

Abstract A collaborative study was conducted to determine the protein content of raw and processed meat products by a protein-tagging and colorimetric technique. Meat products were prepared following AOAC Official MethodSM 983.18 and analyzed using CEM Corporation's Sprint Rapid Protein Analyzer. Sprint provides protein results by combining an accurately weighed test portion with a known amount of dye-binding agent. The dye-binding agent binds with the lysine, histidine, and arginine, as well as the n-terminus of the proteins commonly found in raw meat and processed meat products. Results are displayed and reported by the Sprint as a percentage (g/100 g) of protein. Ten blind duplicate study samples were sent to 10 collaborating laboratories in the United States. The within-laboratory (repeatability) relative standard deviation (RSDr) ranged from 0.91 to 3.04%, and between-laboratories (reproducibility) relative standard deviation (RSDR) ranged from 1.50 to 3.41% for protein. The method is recommended for Official First Action.

scholarly journals Determination of Water (Moisture) and Dry Matter in Animal Feed, Grain, and Forage (Plant Tissue) by Karl Fischer Titration: Collaborative Study

2002 ◽  
Vol 85 (2) ◽  
pp. 318-327 ◽  
Author(s):  
Nancy J Thiex ◽  
Terri van Erem ◽  
D Amundson ◽  
J Boucher ◽  
A Clark ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Dry Matter ◽  
Animal Feed ◽  
Collaborative Study ◽  
Extraction Procedure ◽  
The United States ◽  
Karl Fischer Titration ◽  
Karl Fischer ◽  
Relative Standard

Abstract A Karl Fischer method for determining water (dry matter) in animal feed and forages was collaboratively studied. Water was extracted from animal feed or forage material into methanol–formamide (1 + 1) directly in the Karl Fischer titration vessel by high-speed homogenization. The water was titrated at 50°C with one-component Karl Fischer reagent based on imidazole. Ten blind samples were sent to 9 collaborators in the United States, Canada, and Germany. The within-laboratory relative standard deviation (repeatability) ranged from 1.14 to 6.99% for water or from 0.09 to 0.56% for dry matter. Among-laboratory (including within-) relative standard deviation (reproducibility) ranged from 5.35 to 10.73%, or from 0.44 to 0.77% for dry matter. The authors recommend that the method be adopted as Official First Action by AOAC INTERNATIONAL. A comparable alternative extraction procedure using boiling methanol is also recommended for Official First Action.

Multifunctional Column Coupled with Liquid Chromatography for Determination of Aflatoxins B1, B2, G1, and G2 in Corn, Almonds, Brazil Nuts, Peanuts, and Pistachio Nuts: Collaborative Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1512-1521 ◽  
Author(s):  
Mary W Trucksess ◽  
Michael E Stack ◽  
Stanley Nesheim ◽  
Richard H Albert ◽  
Thomas R Romer
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
The United States ◽  
Test Portion ◽  
Brazil Nuts ◽  
Pistachio Nuts ◽  
Relative Standard

Abstract An AOAC/IUPAC collaborative study was conducted to evaluate the effectiveness of a multifunctional column for the determination of aflatoxins. The test portion is extracted with acetonitrile–water (9 + 1), the extract is filtered, and the filtrate is passed through the column. The aflatoxins in the eluate are determined by reversed-phase liquid chromatography after derivatization with trifluoroacetic acid. Naturally contaminated corn, almonds, Brazil nuts, peanuts, and pistachio nuts spiked with total aflatoxins at 5,10,20, and 30 ng/g were sent to 12 collaborators in the United States, Denmark, France, Japan, and Switzerland. Eleven collaborators completed the study. Average recoveries of total aflatoxins for each spike level for the various commodities (excluding Brazil nuts at 5 ng/g) were 93,97,95, and 95%, respectively; the repeatability relative standard deviation (RSDr) ranged from 6.0 to 23.2% and the reproducibility relative standard deviation (RSDR) ranged from 12.0 to 69.4%. The multifunctional column coupled with a liquid chromatographic method for determination of aflatoxins in corn, almonds, Brazil nuts, peanuts, and pistachio nuts has been adopted first action by AOAC INTERNATIONAL.

scholarly journals Determination of Methylcellulose and Hydroxypropyl Methylcellulose Food Gums in Food and Food Products: Collaborative Study

2007 ◽  
Vol 90 (3) ◽  
pp. 786-793 ◽  
Author(s):  
Robert G Harfmann ◽  
Balasaheb K Deshmukh ◽  
Jerry Conklin ◽  
Maciej Turowski ◽  
Stephanie Lynch ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Hydroxypropyl Methylcellulose ◽  
Collaborative Study ◽  
Food Samples ◽  
Size Exclusion ◽  
Official Method ◽  
Relative Standard ◽  
Aoac Official

Abstract A collaborative study was performed to determine the reproducibility of a method for the determination of methylcellulose (MC) and hydroxypropyl methylcellulose (HPMC) in food. These widely used food gums possess unusual solubility characteristics and cannot accurately be determined by existing dietary fiber methods. The new method uses the enzyme-digestion procedure of AOAC Official Method 991.43. Digestate solutions must be refrigerated to fully hydrate MC or HPMC. The chilled solutions are filtered and analyzed by size-exclusion liquid chromatography. Collaborating laboratories received 28 samples containing MC or HPMC in the range of 0100%. The sample set included blind duplicates of 5 food matrixes (bread, milk, fish, potato, and powdered juice drink). Cochran and Grubbs tests were used to eliminate outliers. For food samples containing MC, values for within-laboratory precision, repeatability relative standard deviation (RSDr), ranged from 4.2 to 16%, and values for among-laboratories precision, reproducibility relative standard deviation (RSDR), ranged from 11 to 20%. For HPMC samples, RSDr values ranged from 6.4 to 27%, and RSDR values ranged from 17 to 39%. Recoveries of MC and HPMC from the food matrixes ranged from 78 to 101%. These results show acceptable precision and reproducibility for the determination of MC and HPMC, for which no Official AOAC Methods exist. It is recommended that this method be adopted as AOAC Official First Action.

Determination of Bismuth in Pharmaceutical Dosage Forms by Conventional DC Polarography

1972 ◽  
Vol 55 (1) ◽  
pp. 155-160
Author(s):  
William M Plank
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Dosage Forms ◽  
Official Method ◽  
Pharmaceutical Dosage Forms ◽  
Relative Standard ◽  
Dc Polarography

Abstract A method has been investigated for the determination of bismuth in pharmaceutical dosage forms by conventional dc polarography. The method is applicable to tablets, emulsions, suspensions, injectables, and bulk powders. A collaborative study has shown the method to be superior in accuracy and precision to the present official colorimetric method, 36.300- 36.304. The results from 16 determinations performed by 8 collaborators were: 100.0±1.5% recovery on a synthetic powder mix, a relative standard deviation of 1.9% on a commercial tablet sample, and a relative standard deviation of 2.1% on a magma sample. By comparison, the collaborative data reported for the present official method gave relative standard deviations of 3.4 and 3.2% on 2 samples of powder mixtures. It is recommended that the polarographic method be adopted as official first action.

Determination of pH of Soils by Different Methods: Collaborative Study

1995 ◽  
Vol 78 (2) ◽  
pp. 310-324 ◽  
Author(s):  
Yash P Kalra
Keyword(s):  
Standard Deviation ◽  
Organic Carbon ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
The United States ◽  
Organic Soils ◽  
Sodic Soils ◽  
Ph Measurements ◽  
Relative Standard ◽  
Mineral Soils

Abstract Fifty-three laboratories (including author’s) from Canada, India, Israel, and the United States participated in a collaborative study for the measurement of pH of different types of soils. A method with 2 alternative procedures was used for pH measurements of mineral soils (alternative I for soils containing less than 17⋊ organic carbon and alternative II for soils with variable salt content), a second method was used for saline-sodic soils, and a third method was used for organic soils (soils containing at least 17⋊ organic carbon). The pH was measured potentiometricaIly. The methods were selected by the Soil Science Society of America, S889 Committee on Coordination of Official Methods of Soil Analysis. Each laboratory used all 4 procedures to analyze 10 blind duplicate samples per procedure. The repeatability relative standard deviation values (RSDr) were 1.45–7.80% for mineral soils tested by the alternative 1,0.95–6.91% for mineral soils tested by the alternative II, 0.74–7.09% for saline-sodic soils, and 0.73–4.66% for organic soils. The corresponding reproducibility relative standard deviation (RSDR) values were 2.67–10.75%, 2.03–7.54%, 2.45–9.93%, and 2.15–6.32%. Repeatability and reproducibility data indicated that the results are within acceptable levels. The 3 methods for pH measurements of mineral, saline-sodic, and organic soils were adopted first action by AOAC INTERNATIONAL.

Immunoaffinity Column Coupled with Solution Fluorometry or Liquid Chromatography Postcolumn Derivatization for Determination of Aflatoxins in Corn, Peanuts, and Peanut Butter: Collaborative Study

1991 ◽  
Vol 74 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Mary W Trucksess ◽  
Michael E stack ◽  
Stanley Nesheim ◽  
Samuel W Page ◽  
Richard H Albert ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Peanut Butter ◽  
Collaborative Study ◽  
The United States ◽  
Affinity Column ◽  
Immunoaffinity Column ◽  
Relative Standard

Abstract An AOAC/IUPAC (International Union of Pure and Applied Chemistry) collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column for the determination of af latoxin. The test portion Is extracted with methanol- water (7 + 3), filtered, diluted to ⦟30% methanol with water, and applied to the affinity column. The column Is washed with water and the concentrated aflatoxins are eluted with methanol. Total aflatoxins are determined by solution fluorometry with bromine (SFB), and Individual toxins are determined by reverse-phase liquid chromatography with postcolumn derlvatizatlon with Iodine (PCD). Corn naturally contaminated with aflatoxins, and peanuts, peanut butter, and corn containing added aflatoxins ( B1:B2:G1G2 = 7:1:3:1) were sent to 24 collaborators In the United States, France, Canada, and the Republic of South Africa. Twelve collaborators used the SFB method, 9 used the PCD method, and 3 used both SFB and PCD methods. Twenty collaborators completed the study (10 used the SFB method, 7 used the PCD method, and 3 used both SFB and PCD methods). Test portions were spiked at 10, 20, and 30 ng/g. For SFB analyses, recoveries of total aflatoxins were 123,105, and 107%, respectively; the relative standard deviation for repeatability (RSDr) ranged from 11.75 to 16.57%, and the relative standard deviation for reproducibility (RSDR) ranged from 10.97 to 33.09%. For PCD analyses, recoveries were 81, 81, and 83%, respectively; the RSDr ranged from 5.20 to 17.22%, and the RSDR ranged from 4.68 to 50.77%. The RSDr for aflatoxins B1, and G1 for spiked test portions ranged from 5.45 to 23.55%, and the RSDR ranged from 4.21 to 57.28%. The RSDr and RSDR for aflatoxins B2 and G2 were higher because of the small amounts added. Analyses by both SFB and PCD methods showed acceptable within-laboratory and betweenlaboratories precision. The method has been adopted official first action by AOAC as an AOAC-IUPAC method.

scholarly journals Determination of Reserpine and Rescinnamine in Rauwolfia serpentina Powders and Tablets: Collaborative Study

1998 ◽  
Vol 81 (2) ◽  
pp. 373-380 ◽  
Author(s):  
Cieri Ugo R ◽  
◽  
Leland Alexander ◽  
Miguel Colon ◽  
Danielle Frost ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
Emission Wavelength ◽  
Excitation Wavelength ◽  
Official Method ◽  
Fluorescence Detector ◽  
Rauwolfia Serpentina ◽  
Relative Standard

abstract A liquid chromatographic (LC) method for determining reserpine and rescinnamine in Rauwolfia serpentina powders and tablets, which uses fluorescence detection, was subjected to a collaborative study. The procedure for extraction and purification is a simplified version of that used in the current official method for analysis of these products. LC separations are performed on a normal- phase column. The mobile phase is methanol to which a small volume of an aqueous solution of 1-pentanesulfonic acid sodium salt can be added to achieve desired elution characteristics. Reserpine and rescinnamine elute at approximately the same time but can be individually quantitated by appropriate settings of the fluorescence detector. Reserpine is determined at an excitation wavelength of 280 nm and an emission wavelength of 360 nm, because rescinnamine is completely nonfluorescent at these wavelengths. Rescinnamine is determined at an excitation wavelength of 330 nm and an emission wavelength of 435 nm, because reserpine is completely nonfluorescent at these wavelengths. The following materials were used for the study: one sample of United States Pharmacopeia (USP) standard R. serpentina powder, one tablet type labeled as containing 100 mg R. serpentina and 2 tablet types labeled as containing 50 mg R. serpentina. For each of the 4 materials, 2 pairs of blind duplicates were prepared. Three materials were analyzed in duplicate by 8 laboratories. One of the 2 tablets labeled to contain 50 mg ft serpentina was analyzed only by 7 of 8 participating laboratories. Average combined content of reserpine and rescinnamine was 0.144% for the USP raw material and 0.132, 0.135, and0.137% for the 3 commercial tablets. Reproducibility relative standard deviation values were 5.72, 5.93, 8.61, and 3.48% and repeatability relative standard deviation values were 2.57, 4.87, 3.19, and 1.99% for the 4 samples. The Associate Referee conducted a study to determine recoveries of reserpine plus rescinnamine by this method from mixtures simulating sample extracts. Average recovery of 15 determinations was 100.1%, with a relative standard deviation of 1.3%. The LC method for determination of reserpine and rescinnamine in R. serpentina powders and tablets has been adopted first action by AOAC INTERNATIONAL.

scholarly journals Liquid Chromatographic Determination of Monensin in Premix and Animal Feeds: Collaborative Study

1997 ◽  
Vol 80 (4) ◽  
pp. 693-702 ◽  
Author(s):  
Mark R Coleman ◽  
John W Moran ◽  
Daniel H Mowrey ◽  
J P Antalick ◽  
D J Bark ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
The United States ◽  
Animal Feeds ◽  
Relative Standard ◽  
Cattle Feeds ◽  
Microbiological Assays ◽  
Liquid Chromatographic

Abstract An interlaboratory study of a liquid chromatographic (LC) method for determining monensin in premix (60–80 g/lb or 132–5176 mg/g) and animal feeds (5–200 g/ton or 0.0055–0.22 mg/g) was conducted in laboratoriesin the United States, Canada, France, and Germany. The LC system used a reversed- phase column, postcolumn derivatization with vanillin, and UV detection. The method separates monensin from other ionophores such as narasin and salinomycin. Each laboratory analyzed a total of 20 samples of premix, liquid feed supplements, poultry, and cattle feeds. Concentrations of monensin in all samples ranged from 0 to 176 mg/g (80 g/lb). Reproducibility relative standard deviation (RSDR) for premix ranged from 2.8 to 3.4%. For feed samples containing monensin, repeatability standard deviation (Sr) ranged from 0.9 to 7.0. Reproducibility standard deviation (SR) ranged from 1.2 to 11. Repeatability relative standard deviation (RSDr) ranged from 6.1 to 21% and RSDR valuesranged from 8.6 to 25%. Sample preparation for the LC method is less labor intensive than that for the microbiological assays. The LC assay is more efficient than the microbiological assays. This LC method for determination of monensin in premix and animal feeds has been adopted first action by AOAC INTERNATIONAL.

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