Collaborative Study of the Determination of Phosphorus in Gelatin, Dessert Preparations, and Mixes

1972 ◽  
Vol 55 (3) ◽  
pp. 581-582
Author(s):  
Roger G Burkepile
Keyword(s):  
Collaborative Study ◽  
Official Method ◽  
Standard Samples ◽  
Preliminary Work ◽  
Aoac Method ◽  
Standard Deviations

Abstract A collaborative study of the proposed method for phosphorus in gelatin, dessert preparations, and mixes has been conducted. The present AOAC method for phosphorus in fertilizers, 2.023–2.025(a), was modified for this study. Preliminary work by the Associate Referee involving 4 phosphorus standard samples compared the proposed method with the official final action AOAC method for gelatin, 23.004. Additionally, phosphorus standard spikes in gelatin at the 1 and 10 mg P2O5, levels were determined by the proposed method. The proposed method is faster and more sensitive than the official method and is as accurate. Five collaborators and the Associate Referee analyzed 4 prepared samples containing various levels of phosphorus by the proposed method. The standard deviations varied from 0.005 for a 225 Bloom gelatin containing an average of 0.273% P2O5 to 0.016 for a strawberry-flavored commercial gelatin with added lecithin containing an average of 0.110% P2O5. The proposed method has been adopted as official first action to replace 23.004, which was repealed, official first action.

Collaborative Study of the Quantitative Gas-Liquid Chromatographic Determination of Fusel Oil and Other Components in Whisky

1972 ◽  
Vol 55 (3) ◽  
pp. 549-556
Author(s):  
J H Kahn ◽  
E T Blessinger
Keyword(s):  
Ethyl Acetate ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Official Method ◽  
Fusel Oil ◽  
Fusel Alcohols ◽  
Aoac Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Fifteen chemists participated in a collaborative study for the quantitative pas-liquid chromatographic determination of the individual fusel alcohols and ethyl acetate in whisky. Two levels of congeners represented by 4 coded samples of whisky were analyzed by using t h e proposed method, employing a glycerol-1,2,6-hexanetriol column, and the official AOAC method, 9.063-9.065. Since isobutyl and the atnyl alcohols comprise by far the greatest part of fusel oil, their determination is of major importance to the total fusel oil content . Statistical analyses show that the proposed method is superior to the AOAC method for the determination of these alcohols, whereas the official method is superior for the determination of ethyl acetate and n-propyl alcohol. In general, collaborators employing modern instrumentation preferred the proposed method over the AOAC method. The former method also separates and permits the quantitative measurement of active amyl and isoamyl alcohols. The proposed method has been adopted as official first action as an alternative to 9.063–9.065 for the determination of higher alcohols and ethyl acetate in whisky.

Collaborative Study of the Quantitative Determination of Fusel Oil and Ethyl Acetate by Gas-Liquid Chromatography

1968 ◽  
Vol 51 (4) ◽  
pp. 915-921
Author(s):  
Richard L Brunelle
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Ethyl Acetate ◽  
Simultaneous Determination ◽  
Collaborative Study ◽  
Gas Liquid Chromatography ◽  
Fusel Oil ◽  
Preliminary Work ◽  
Standard Deviations

Abstract Thirteen chemists representing twelve laboratories participated in a collaborative study for the quantitative determination of ethyl acetate and fusel oil by GLC. The results on four samples containing various amounts of ethyl acetate and fusel oil were compared with the official AOAC procedures. For all samples, the standard deviations were lower with GLC. Collaborators preferred the GLC procedure because the simultaneous determination of ethyl acetate and n-propyl, iso-butyl, and isoamyl alcohols is possible. Results from preliminary work performed on the quantitative determination of acetaldehyde by GLC were encouraging. It is recommended that the proposed GLC procedure for the quantitative determination of ethyl acetate and fusel oil be adopted as official, first action, and that work be continvied on the determination of acetaldehyde by GLC.

Collaborative Study of Ion Selective Electrode Method for the Direct Determination of Fluoride in Feeds

1975 ◽  
Vol 58 (3) ◽  
pp. 477-481 ◽  
Author(s):  
Laszlo Torma
Keyword(s):  
Standard Deviation ◽  
Collaborative Study ◽  
Direct Determination ◽  
Ion Selective Electrode ◽  
Official Method ◽  
Selective Electrode ◽  
Standard Curve ◽  
Electrode Method ◽  
Aoac Method

Abstract A rapid and precise method for the determination of fluoride in feeds employs HC1 extraction of the sample. Acetate buffer and sodium citrate are added to control pH and ionic strength. The amount of fluoride is calculated from a standard curve after measuring the potentials of standard and sample solutions. Eight collaborators participated in the study of the method. Statistical values on 3 pairs of samples were calculated. The standard deviation, precision, coefficient of variation, and bias, respectively, were: Pair 1, 0.005071, 0.001763, 3.09, 0.0034; Pair 2, 0.037122, 0.006475, 1.82, 0.0258; Pair 3, 0.034587, 0.013021, 2.63, 0.0227. The results from the proposed method agreed favorably with the values obtained by using the official final action AOAC method, 7.089. The average and standard deviation, respectively, for individual samples by the proposed method were: Sample 3, 0.049, 0.0029; Sample 4, 0.059, 0.0021; Sample 5, 0.334, 0.0114; Sample 6, 0.341, 0.0101; Sample 7, 0.511, 0.0219; Sample 8, 0.492, 0.0237. By the official method the values were: Sample 3, 0.049, 0.0041; Sample 4, 0.058, 0.0029; Sample 5, 0.334, 0.0055; Sample 6, 0.331, 0.0082; Sample 7, 0.517, 0.0183; Sample 8, 0.499, 0.0175. The ion selective electrode method has been adopted as official first action.

scholarly journals Determination of Total Dietary Fiber (CODEX Definition) by Enzymatic-Gravimetric Method and Liquid Chromatography: Collaborative Study

2010 ◽  
Vol 93 (1) ◽  
pp. 221-233 ◽  
Author(s):  
Barry V McCleary ◽  
Jonathan W De Vries ◽  
Jeanne I Rader ◽  
Gerald Cohen ◽  
Leon Prosky ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Dietary Fiber ◽  
Resistant Starch ◽  
Collaborative Study ◽  
Gravimetric Method ◽  
Low Molecular Weight ◽  
Total Dietary Fiber ◽  
Aoac Method ◽  
Standard Deviations

Abstract A method for the determination of total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official MethodsSM 985.29, 991.43, 2001.03, and 2002.02, the method quantitates high- and low-molecular-weight dietary fiber (HMWDF and LMWDF, respectively). In 2007, McCleary described a method of extended enzymatic digestion at 37C to simulate human intestinal digestion followed by gravimetric isolation and quantitation of HMWDF and the use of LC to quantitate low-molecular-weight soluble dietary fiber (LMWSDF). The method thus quantitates the complete range of dietary fiber components from resistant starch (by utilizing the digestion conditions of AOAC Method 2002.02) to digestion resistant oligosaccharides (by incorporating the deionization and LC procedures of AOAC Method 2001.03). The method was evaluated through an AOAC collaborative study. Eighteen laboratories participated with 16 laboratories returning valid assay data for 16 test portions (eight blind duplicates) consisting of samples with a range of traditional dietary fiber, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 11.57 to 47.83. Digestion of samples under the conditions of AOAC Method 2002.02 followed by the isolation and gravimetric procedures of AOAC Methods 985.29 and 991.43 results in quantitation of HMWDF. The filtrate from the quantitation of HMWDF is concentrated, deionized, concentrated again, and analyzed by LC to determine the LMWSDF, i.e., all nondigestible oligosaccharides of degree of polymerization 3. TDF is calculated as the sum of HMWDF and LMWSDF. Repeatability standard deviations (sr) ranged from 0.41 to 1.43, and reproducibility standard deviations (sR) ranged from 1.18 to 5.44. These results are comparable to other official dietary fiber methods, and the method is recommended for adoption as Official First Action.

Collaborative Study of Determination of Silicon in Agricultural Liming Materials

1963 ◽  
Vol 46 (4) ◽  
pp. 603-610
Author(s):  
P Chichilo
Keyword(s):  
Silicon Content ◽  
Standard Sample ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Standard Samples ◽  
Prefer Method ◽  
Aoac Method

Abstract Six samples of liming materials, including carbonates and silicates, were analyzed for silicon content by: (I) The AOAC method; (II) the AOAC method plus volatilization of SiO2 with HF; (III) the AOAC method, omitting the Na2CO3 fusion of the sample, including the HClO4 dehydration of SiO2, plus HF volatilization of SiO2; and (IV) a colorimetric method. Nine collaborators reported results by Methods I, II, and III and eleven by Method IV. Precision of the methods was good; no method was superior for all samples. Method I gave high results for most samples; the average result with Method I for a standard sample of dolomite was high, but that for a standard limestone was near the certificate value. Average results by Methods II, III, and IV for the standard samples were near certificate values. The collaborators appeared to prefer Method IV.

scholarly journals Gravimetric Determination of Acid Detergent Fiber and Lignin in Feed: Interlaboratory Study

2009 ◽  
Vol 92 (1) ◽  
pp. 74-90 ◽  
Author(s):  
Jürgen Möller ◽  
J Arananant ◽  
K Boonnayanont ◽  
J Danier ◽  
M Egert ◽  
...  
Keyword(s):  
Animal Feed ◽  
Collaborative Study ◽  
Official Method ◽  
Acid Detergent Fiber ◽  
Cattle Feed ◽  
Gravimetric Determination ◽  
Soy Meal ◽  
Aoac Official ◽  
Standard Deviations

Abstract On the basis of AOAC Official Method 973.18, a collaborative study was performed to determine fractions of acid detergent fiber (ADF) and lignin (ADL) in animal feed. The study used 6 animal feed and forage samples as blind duplicates and involved 22 participants from 7 countries. The samples analyzed covered a range from 3.5 to 70 ADF and from <1 to 20 ADL. Repeatability standard deviations ranged from 0.27 to 0.95 for ADF and from 0.08 to 0.59 for ADL. The reproducibility standard deviations ranged from 0.56 to 2.44 for ADF and from 0.52 to 2.09 for ADL. Analyzed samples comprised clover and grass silages, soy meal, cattle feed, wheat, and sawdust. The studied method has been published as the EN ISO 13906:2008 standard.

scholarly journals Gas Chromatographic Method for Putrescine and Cadaverine in Canned Tuna and Mahimahi and Fluorometric Method for Histamine (Minor Modification of AOAC Official Method 977.13): Collaborative Study

1997 ◽  
Vol 80 (3) ◽  
pp. 591-602 ◽  
Author(s):  
Patricia L Rogers ◽  
Walter Staruszkiewicz ◽  
A Adams ◽  
B Atienza ◽  
R J Berg ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Official Method ◽  
Fluorometric Method ◽  
Canned Tuna ◽  
Relative Standard ◽  
Aoac Official ◽  
Standard Deviations ◽  
Ppm Level ◽  
Aoac Official Method

Abstract A collaborative study was conducted to test a modification to the AOAC fluorometric method for histamine (AOAC® Official Method 977.13) that substitutes 75% methanol as the extracting solvent. All other steps remain unchanged. The extracts prepared with 75% methanol were also used to collaboratively test a gas chromatographic (GC) method for determination of putrescine and cadaverine in seafood. In the GC method, the extracted diamines are converted to fluorinated derivatives, the reaction mixtures are passed through solid-phase extraction columns, and the derivatives are quantitated by electron capture GC after separation on an OV-225 column. Fourteen laboratories using the GC method for putrescine and cadaverine and 16 laboratories using the fluorometric method for histamine analyzed 14 canned tuna and raw mahimahi (including blind duplicates and a spike) containing 0.2-2.6 ppm putrescine, 0.6-9.1 ppm cadaverine, and 0.6-154 ppm histamine. At the 5 ppm level, recoveries ranged from 71 to 102% for putrescine and 77 to 112% for cadaverine; the respective repeatability relative standard deviations (RSDr) were 5.2 and 15%, and the respective reproducibility relative standard deviations (RSDR) were 8.8 and 18%. At the 50 ppm level, histamine recoveries ranged from 84 to 125%, RSDr was 3.6%, and RSDR was 9.4%. The GC method for determination of putrescine in canned tuna and cadaverine in canned tuna and mahimahi has been adopted first action by AOAC INTERNATIONAL, and the AOAC Official Method 977.13, Histamine in Seafood, Fluorometric Method, has been modified

Comparison of Three Methods for Determination of Crude Protein in Meat: Collaborative Study

1982 ◽  
Vol 65 (6) ◽  
pp. 1339-1345 ◽  
Author(s):  
Francis B Suhre ◽  
Paul A Corrao ◽  
Angeline Glover ◽  
Anthony J Malanoski ◽  
◽  
...  
Keyword(s):  
Crude Protein ◽  
Steam Distillation ◽  
Collaborative Study ◽  
Distillation Method ◽  
Reference Procedure ◽  
Kjeldahl Method ◽  
Aoac Method ◽  
Repeatability And Reproducibility ◽  
Standard Deviations

Abstract A study was designed to compare the Kjel-Foss automated macro-Kjeldahl method and a block digestion- steam distillation method. The official AOAC Kjeldahl method was used as a reference procedure. Six products with a crude protein range of 10-30% were analyzed by 23 laboratories. Five laboratories analyzed the samples by the official AOAC method, 8 laboratories used the automated Kjel-Foss method, and 11 laboratories used the block digestion with steam distillation method. Standard deviations for each product and each method for both repeatability and reproducibility are given. The block digestion- steam distillation method has been adopted official first action.

Collaborative Study of a Joint AOAC-OICC (Office International du Cacao et du Chocolat) Method for the Determination of Alkalinity of Ash in Cacao Products

1975 ◽  
Vol 58 (1) ◽  
pp. 150-155
Author(s):  
Walter Rostagno
Keyword(s):  
Cocoa Butter ◽  
Collaborative Study ◽  
Uniform Method ◽  
Milk Chocolate ◽  
Aoac Method ◽  
Standard Deviations ◽  
Milk Solids

Abstract In order to develop a uniform method for the determination of alkalinity of soluble and insoluble ash, AOAC methods 13.005 and 13.006 and OICC method 4b/1952 were compared. Five samples were sent to 10 collaborators: A, high ash cocoa; B, low ash cocoa; C, breakfast chocolate containing 30% A and 70% sugar; D, plain chocolate containing 25% B, 45% sugar, and 30% cocoa butter; and E, milk chocolate containing 10% B, 28% milk solids, 40% sugar, and 22% cocoa butter. The following within-laboratory and between-laboratory standard deviations were obtained from analysis of the collaborative data for alkalinity in soluble ash: OICC—Samples A and B, 1.5116 and 3.4337; Samples C–E, 0.7285 and 1.0394; AOAC—Samples A and B, 1.2800 and 3.6996; Samples C–E, 0.2956 and 0.8001. Corresponding values for alkalinity in insoluble ash were: OICC—2.1753 and 3.6856, 0.5100 and 1.0029; AOAC—1.5652 and 5.5006, 0.3129 and 1.6501. On the basis of these results, a joint AOACOICC method, based on the determination of alkalinity in soluble ash by the AOAC method and the determination of alkalinity in insoluble ash by the OICC method, has been adopted as official first action.

Collaborative Study of a Method for the Determination of Weight Per Unit Volume of Packaged Ice Cream

1968 ◽  
Vol 51 (4) ◽  
pp. 807-810
Author(s):  
Larry E Habeger
Keyword(s):  
Weight Loss ◽  
Unit Volume ◽  
Collaborative Study ◽  
Ice Cream ◽  
New Method ◽  
Official Method ◽  
Fixed Volume ◽  
Aoac Method

Abstract A new method and the official AOAC method (15.181) for the determination of weight per unit volume of ice cream were compared in a collaborative study by twelve collaborators in six laboratories. In the official method, hard frozen ice cream is immersed in a specially constructed overflow can filled with deodorized kerosene and the volume of the ice cream is determined by measuring the volume of kerosene displaced. In the new method, hard frozen ice cream is immersed in a container of fixed volume filled with water and the volume of water displaced is determined by weight loss. This study shows that the new method is more precise than the old one. It is therefore recommended that the new method be adopted as official, first action.

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