Comparison of the Volhard and Potentiometric Methods for the Determination of Chloride in Meat Products: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 480-484
Author(s):  
Paul R Beljaars ◽  
William Horwitz
Keyword(s):  
Sodium Chloride ◽  
Collaborative Study ◽  
Meat Products ◽  
Potentiometric Method ◽  
Collaborative Studies ◽  
Relative Standard ◽  
Luncheon Meat ◽  
Iso 5725 ◽  
Good Agreement

Abstract A collaborative study of the determination of chloride in meat products was conducted by the International Organization for Standardization (ISO) to compare the ISO 1841 method (Volhard titration) with the FAO/WHO Codex Alimentarius Committee method (potentiometric titration). Five canned luncheon meat products containing 0.25-2.0% sodium chloride at 4 different spiking levels were analyzed by 11 laboratories. The data were analyzed by ISO statistics (ISO 5725) and by AOAC statistics (Youden-Steiner), the major differences being in the rejection of outliers and in the statement of precision parameters. Good agreement was found between the mean chloride contents of the products as determined by both methods and with the added amounts, although statistically significantly higher sodium chloride recoveries were obtained with the potentiometric method. The within-laboratory variability (repeatability) is greater for the Volhard method, especially for chloride levels below 1.0%. Therefore it is proposed to set the lowest level of determination for the Volhard method at about 1.0% sodium chloride. The among-laboratories variability (reproducibility) of the potentiometric method was comparable with the results from the collaborative studies for chloride in cheese, giving acceptable values for relative standard deviations of 1.5-3.0% for meat products with 0.3-2.0% added sodium chloride. It is recommended that further work be conducted to reduce or eliminate the systematic error present with the potentiometric method as applied to meat and meat

Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

1990 ◽  
Vol 73 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Kurt Kolar
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Meat Products ◽  
Acid Oxidation ◽  
Colorimetric Determination ◽  
Mean Values ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

Sulfuric Acid/Hydrogen Peroxide Digestion and Colorimetric Determination of Phosphorus in Meat and Meat Products: Collaborative Study

1991 ◽  
Vol 74 (1) ◽  
pp. 22-26 ◽  
Author(s):  
David K Christians ◽  
Thomas G Aspelund ◽  
Scott V Brayton ◽  
Larry L Roberts
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Collaborative Study ◽  
Meat Products ◽  
Colorimetric Determination ◽  
Pork Sausage ◽  
Relative Standard ◽  
Significant Difference ◽  
Standard Deviations

Abstract Seven laboratories participated In a collaborative study of a method for determination of phosphorus in meat and meat products. Samples are digested In sulfuric acid and hydrogen peroxide; digestion Is complete In approximately 10 mln. Phosphorus Is determined by colorimetric analysis of a dilute aliquot of the sample digest. The collaborators analyzed 3 sets of blind duplicate samples from each of 6 classes of meat (U.S. Department of Agriculture classifications): smoked ham, water-added ham, canned ham, pork sausage, cooked sausage, and hamburger. The calibration curve was linear over the range of standard solutions prepared (phosphorus levels from 0.05 to 1.00%); levels in the collaborative study samples ranged from 0.10 to 0.30%. Standard deviations for repeatability (sr) and reproducibility (sR) ranged from 0.004 to 0.012 and 0.007 to 0.014, respectively. Corresponding relative standard deviations (RSDr and RSDR, respectively) ranged from 1.70 to 7.28% and 3.50 to 9.87%. Six laboratories analyzed samples by both the proposed method and AOAC method 24.016 (14th Ed.). One laboratory reported results by the proposed method only. Statistical evaluations Indicated no significant difference between the 2 methods. The method has been adopted official first action by AOAC.

Determination of Nitrate in Vegetables by Continuous Flow: Interlaboratory Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1522-1529 ◽  
Author(s):  
Paul R Beljaars ◽  
Remmelt Van Duk ◽  
Geertrutoa M Van Der Horst
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Continuous Flow ◽  
Collaborative Study ◽  
Leafy Vegetables ◽  
Collaborative Studies ◽  
Relative Standard ◽  
Metallic Cadmium ◽  
Inspection Service

Abstract A collaborative study for the determination of nitrate in leafy vegetables, such as endive, lettuce, spinach, and beetroot, by continuous flow (CF) was conducted by the Project Group on Collaborative Studies of the Inspectorate for Health Protection, Food Inspection Service, in The Netherlands. After extraction with water and filtration, samples were cleaned up by dialysis in the CF system. Extracted nitrates were reduced to nitrite in the system by metallic cadmium, and then the nitrite was reacted with sulfanilamide and N-naphthylethylenediamine to form a reddish-purple azo dye. This dye was measured colorimetrically at 530 nm. Fourteen vegetable samples (including 7 blind duplicates) containing nitrate at ca 900 to 5200 mg/kg were analyzed singly by the proposed procedure by 13 laboratories. The data were analyzed by the International Union for Pure and Applied Chemistry (IUPAC)–International Organization for Standardization (ISO)–AOAC protocol for statistics. One collaborator was identified as an outlier for all results. For all samples analyzed, the repeatability relative standard deviation values varied from 1.7 to 5.5%, whereas the reproducibility relative standard deviation values ranged from 3.3 to 5.9%.

Enzymatic Determination of Free Glutamic Acid in Dried Soups and in Minced Sausages: NMKL1 Collaborative Study

1991 ◽  
Vol 74 (6) ◽  
pp. 921-925 ◽  
Author(s):  
M Tapani Hattula ◽  
Harriet C Wallin ◽  
◽  
R Andersen ◽  
K Blomberg ◽  
...  
Keyword(s):  
Glutamic Acid ◽  
Collaborative Study ◽  
Meat Products ◽  
Visible Range ◽  
Enzymatic Method ◽  
Study Materials ◽  
Enzymatic Determination ◽  
Relative Standard ◽  
The Mean

Abstract An enzymatic method for the determination of free glutamic acid in meat products and dried soups was collaboratively studied in 11 laboratories. In the presence of the enzyme glutamate dehydrogenase, L-giutamic acid is oxidatively deaminated by nicotinamide adenine dinucleotide (NAD) to 2-oxoglutarate. In a reaction catalyzed by diaphorase, the NADH thus formed converts 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride to a formazan, which is measured in the visible range at 492 nm. Fourteen samples (7 samples of minced sausage and 7 samples of dried cauliflower soup) with glutamate contents varying between 0.4 and 16 g/kg were included In the study. Materials were distributed to participants as blind duplicates and as split level pairs. The mean relative standard deviation (RSDR) for reproducibility for the dried soup material containing glutamate between 7 and 16 g/kg was 4.6%. RSDR values for samples of minced sausage containing glutamate at lower levels (0.4-1.3 g/kg) were between 12 and 16%.

Enzyme Immunoassay for Determination of Gluten in Foods: Collaborative Study

1991 ◽  
Vol 74 (2) ◽  
pp. 257-264 ◽  
Author(s):  
John H Skerritt ◽  
Amanda S Hill
Keyword(s):  
Enzyme Immunoassay ◽  
Collaborative Study ◽  
Wheat Gluten ◽  
Meat Products ◽  
Processed Meat ◽  
Cereal Products ◽  
Relative Standard ◽  
Cooked Meats ◽  
Wheat Flours

Abstract A collaborative study was performed In 15 laboratories to validate a monoclonal antibody-based enzyme Immunoassay (EIA) for determination of gluten in foods. The study Included 13 samples: maize starch, "gluten-free" baking mixes, wheat flours, cookies, cooked meats, and a soup. Gluten was present In these samples at either zero or 0.02 to 10% by weight, I.e., over almost 3 orders of magnitude. The mean assay values for the foods varied from 88 to 105% of the actual amounts. The assay was quantitative for cereal products and the soup with repeatability (RSDr, relative standard deviation) and reproducibility (RSDR) of 16-22% and 24-33%, respectively. The assay was semiquantitative for the processed meat products (RSDr 14 and 26% and RSDr 46 and 56%), probably because gluten was unevenly distributed In the small (1 g) samples that were analyzed. The ELISA method produced no false positive results, and false negatives obtained with tannin-containing foods could be avoided by use of a modified sample extractant. None of the collaborators reported problems In following the protocol. The method has been adopted official first action by AOAC for determination of wheat gluten in foods.

Combustion Method for Determination of Crude Protein in Meat and Meat Products: Collaborative Study

1993 ◽  
Vol 76 (4) ◽  
pp. 787-793 ◽  
Author(s):  
Brink Marcia King ◽  
Sebranek Joseph G. ◽  
◽  
C Anthony ◽  
P Coleman ◽  
...  
Keyword(s):  
Crude Protein ◽  
Collaborative Study ◽  
Meat Product ◽  
Meat Products ◽  
Combustion Method ◽  
Relative Standard ◽  
Kjeldahl Method ◽  
Standard Deviations ◽  
Meat Samples

Abstract Twelve laboratories participated in a collaborative study to compare a combustion method with the AOAC mercury catalyst Kjeldahl method (928.08) for the determination of crude protein in meat and meat products. Three different combustion instruments were used; consequently, the combustion method for this study is written in generic terms describing the principle, the apparatus specifications, and the performance requirements needed. Fifteen sample pairs were used for the study; each pair consisted of the same commercial meat product from each of 2 different manufacturers. Protein content of all samples ranged from about 10 to 20%. In addition, nicotinic acid and lysine monohydrochloride were used as standards to assess combustion equipment performance. All laboratories and all instruments performed the combustion method satisfactorily on the basis of results for the standards. For the meat samples, repeatability standard deviations (sr) ranged from 0.11 to 0.40 for the Kjeldahl method and from 0.12 to 0.41 for the combustion method; the repeatability relative standard deviations (RSDr) ranged from 0.82 to 2.41% and from 0.60 to 2.23% for the Kjeldahl and combustion methods, respectively. Reproducibility standard deviations (SR) ranged from 0.20 to 0.49 for the Kjeldahl method and from 0.18 to 0.46 for the combustion method, whereas the reproducibility relative standard deviations (RSDR) ranged from 1.59 to 2.84% for the Kjeldahl method and from 1.32 to 3.35% for the combustion method. Overall grand means were 15.59% protein for the Kjeldahl method and 15.75% protein for the combustion method. The combustion method was adopted first action by AOAC International.

scholarly journals Determination of Fat,Moisture, and Protein in Meat and Meat Products by Using the FOSS FoodScan Near-Infrared Spectrophotometer with FOSS Artificial Neural Network Calibration Model and Associated Database: Collaborative Study

2007 ◽  
Vol 90 (4) ◽  
pp. 1073-1083 ◽  
Author(s):  
Shirley Anderson ◽  
S Aldana ◽  
M Beggs ◽  
J Birkey ◽  
A Conquest ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Standard Deviation ◽  
Near Infrared ◽  
Collaborative Study ◽  
Meat Products ◽  
Calibration Model ◽  
Relative Standard ◽  
Infrared Spectrophotometer

Abstract A collaborative study was conducted to evaluate the repeatability and reproducibility of the FOSS FoodScan near-infrared spectrophotometer with artificial neural network calibration model and database for the determination of fat, moisture, and protein in meat and meat products. Representative samples were homogenized by grinding according to AOAC Official Method 983.18. Approximately 180 g ground sample was placed in a 140 mm round sample dish, and the dish was placed in the FoodScan. The operator ID was entered, the meat product profile within the software was selected, and the scanning process was initiated by pressing the start button. Results were displayed for percent (g/100 g) fat, moisture, and protein. Ten blind duplicate samples were sent to 15 collaborators in the United States. The within-laboratory (repeatability) relative standard deviation (RSDr) ranged from 0.22 to 2.67% for fat, 0.23 to 0.92% for moisture, and 0.35 to 2.13% for protein. The between-laboratories (reproducibility) relative standard deviation (RSDR) ranged from 0.52 to 6.89% for fat, 0.39 to 1.55% for moisture, and 0.54 to 5.23% for protein. The method is recommended for Official First Action.

scholarly journals Multiple Mycotoxins Determination in Food by LC-MS/MS: An International Collaborative Study

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 658 ◽  
Author(s):  
Thomas Bessaire ◽  
Claudia Mujahid ◽  
Pascal Mottier ◽  
Aurélien Desmarchelier
Keyword(s):  
Collaborative Study ◽  
Milk Powder ◽  
Food Samples ◽  
Relative Standard ◽  
Liquid Chromatography Tandem Mass ◽  
Mycotoxin Analysis ◽  
Repeatability And Reproducibility ◽  
Iso 5725 ◽  
Infants And Young Children

An intercollaborative study was organized to evaluate the performance characteristics of a liquid chromatography tandem mass spectrometry procedure for the simultaneous determination of 12 mycotoxins in food, which were ochratoxin A, aflatoxins B1, B2, G1, G2, and M1, deoxynivalenol, zearalenone, fumonisins B1 and B2, and T-2 and HT-2 toxins. The method combined the simplicity of the QuEChERS (Quick, Easy, Cheap, Efficient, Rugged and Safe) approach with the efficiency of immunoaffinity column cleanup (the step used to enhance sensitivity and sample cleanup for some matrices only). Twenty-three entities were enrolled and were European reference laboratories for mycotoxin analysis, U.S. and European service laboratories, and Nestlé laboratories. Each participant analyzed 28 incurred and/or spiked blind samples composed of spices, nuts, milk powder, dried fruits, cereals, and baby food using the protocol given. Method performances were assessed according to ISO 5725-2. Relative standard deviations of repeatability and reproducibility and trueness values for each of the 115 mycotoxin/sample combinations ranged from 5% to 23%, 7% to 26%, and 85% to 129%, respectively, in line with requirements defined in EC 401/2006. The overall set of data gathered demonstrated that the method offered a unique platform to ensure compliance with EC 1881/2006 and EC 165/2013 regulations setting maximum limits for mycotoxins in food samples, even at low regulated levels for foods intended for infants and young children. The method was applicable regardless of the food, the regulated mycotoxin, and the concentration level, and thus is an excellent candidate for future standardization.

Enzymatic Method for Determination of (1→3)(1→4)-Beta-D-glucans in Grains and Cereals: Collaborative Study

1993 ◽  
Vol 76 (5) ◽  
pp. 1069-1082 ◽  
Author(s):  
Lucian C Zygmunt ◽  
Steven D Paisley ◽  
◽  
G Bromley ◽  
G Durany ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Enzymatic Assay ◽  
Good Precision ◽  
Enzymatic Method ◽  
Beta Glucan ◽  
Collaborative Studies ◽  
Relative Standard ◽  
Cereal Samples ◽  
Beta Glucosidase

Abstract The McCleary enzymatic assay for mixed linkage (1→3)(1→4)-beta-D-glucans has been modified to apply to oat and barley fractions and ready-to-eat (RTE) cereals. The proposed method involves lower sample concentrations; stirring the samples; a longer, warmer lichenase digestion; and longer beta-glucosidase digestion. These changes result in higher recovery of beta-glucan. This modification expands on the American Association of Cereal Chemists (AACC) Method 32-22 by the addition of a desugaring procedure, which is necessary for RTE cereals. Results from collaborative studies sponsored by AACC and AOAC demonstrate good precision for an enzymatic assay. The average relative standard deviation for reproducibility (RSDR, a measure of inter laboratory variation) for 20 oat, barley, and cereal samples was 9.7%. The average RSD for repeatability (RSDr, intralaboratory variation) was 5.0%. The enzymatic method has been adopted first action by AOAC International for determination of beta-glucans in oat and barley fractions, and ready-to-eat cereals.

Collaborative Study of a Potentiometric Method for the Determination of Fluoride in Vegetation

1975 ◽  
Vol 58 (6) ◽  
pp. 1129-1134 ◽  
Author(s):  
Jay S Jacobson ◽  
Laurence I Heller
Keyword(s):  
Reference Values ◽  
Collaborative Study ◽  
Fluoride Concentration ◽  
Practical Method ◽  
Potentiometric Method ◽  
Selective Electrode ◽  
Collaborative Test ◽  
Relative Standard ◽  
Vegetation Samples

Abstract A collaborative test was performed to evaluate a new potentiometric method for the analysis of fluoride in vegetation. The study was designed to provide estimates of accuracy and within- and between-laboratory precision of a method that employs extraction of fluoride, followed by analysis with an ion selective electrode. A group of laboratories experienced in fluoride analysis was provided with representative aliquots of specially prepared samples of vegetation and a detailed set of instructions. Reference values were established for the fluoride concentrations of vegetation samples prior to their distribution. Nine of the 23 laboratories participating in the study adhered strictly to instructions so the results from these 9 participants were used to evaluate the method. The coefficient of correlation between results from selected laboratories and reference values was 0.999. Deviations from reference values averaged 5.4% and relative standard deviations ranged from about 20% at 24 ppm to about 10% for concentrations >100 ppm fluoride. On the basis of these results, the new method has been adopted as official first action. The method is simpler and faster; it requires less equipment than the current official final action method (25.029–29.035) and can be used to estimate fluoride concentration in the foliage of plants exposed to fluorides in the atmosphere or in soils provided samples contain >10 ppm fluoride. Separate studies indicate, however, that certain samples of vegetation may be refractory to analysis by this potentiometric method. The final action method should be retained until a practical method is developed that is satisfactory for all types of vegetation.

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