Collaborative Study of Maleic Hydrazide Residue Analysis

1965 ◽  
Vol 48 (4) ◽  
pp. 744-748
Author(s):  
J R Lane
Keyword(s):  
Maleic Hydrazide ◽  
Residue Analysis ◽  
Collaborative Study ◽  
French Fries ◽  
Food Crops ◽  
Good Reproducibility ◽  
Processed Food ◽  
Wide Range ◽  
Single Determination

Abstract The recoveries obtained from raw and processed food crops fortified with 10 μg or more of maleic hydrazide per analytical sample demonstrate that a wide range of concentrations of maleic hydrazide residues can be accurately determined. The test shows good reproducibility and agreement of data, considering the additional possible error of a blending at point of origin and reblending upon receipt by the collaborator, the lack of refrigeration, and the use of a single determination of the unknowns. The crops used included cranberries, onions, peaches, tobacco dust, and potatoes (whole, dehydrated mashed, frozen french fries, and potato chips). The average recoveries on these crops, fortified with 1.3–85 ppm, ranged from 70 to 92%.

Residue Analysis of Organophosphorus and Organochlorine Pesticides in Fatty Matrices by Gas Chromatography Coupled with Electron-Capture Detection

2006 ◽  
Vol 61 (5-6) ◽  
pp. 341-346 ◽  
Author(s):  
Jae-Woo Park ◽  
A. M. Abd El-Aty ◽  
Myoung-Heon Lee ◽  
Sung-Ok Song ◽  
Jae-Han Shim
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Simple Procedure ◽  
Linear Regression Analysis ◽  
Residue Analysis ◽  
Electron Capture Detection ◽  
Relative Standard ◽  
Wide Range ◽  
Repeatability And Reproducibility

A multiresidue method for the simultaneous determination of 22 organochlorine (OCs) and organophosphorus (Ops) pesticides (including isomers and metabolites), representing a wide range of physicochemical properties, was developed in fatty matrices extracted from meat. Pesticides were extracted from samples with acetonitrile/n-hexane (v :v, 1:1). The analytical screening was performed by gas chromatography coupled with electron-capture detection (ECD). The identification of compounds was based on their retention time and on comparison of the primary and secondary ions. The optimized method was validated by determining accuracy (recovery percentages), precision (repeatability and reproducibility), and sensitivity (detection and quantitation limits) from analyses of samples fortified at 38 to 300 ng/g levels. Correlation coefficients for the 22 extracted pesticide standard curves (linear regression analysis, n = 3) ranged from 0.998 to 1.000. Recovery studies from 2 g samples fortified at 3 levels demonstrated that the GC-ECD method provides 64.4-96.0% recovery for all pesticides except 2,4′-DDE (44.6-50.4%), 4,4′-DDE (51.1-57.5%) and 2,4′-DDT (50.0-51.2%). Both repeatability and reproducibility relative standard deviation values were < 20% for all residues. Detection limits ranged from 0.31 to 1.27 ng/g and quantification limits were between 1.04 and 4.25 ng/g. The proposed analytical method may be used as a simple procedure in routine determinations of OCs and Ops in meat. It can also be applied to the determination of pesticide multi-residues in other animal products such as butter and milk.

Analysis of Acetone Peroxide Premixes for Bleaching and Maturing Flour

1964 ◽  
Vol 47 (2) ◽  
pp. 363-366
Author(s):  
James T Taylor
Keyword(s):  
Hydrogen Peroxide ◽  
Qualitative Method ◽  
Collaborative Study ◽  
Organic Peroxides ◽  
Dilute Sulfuric Acid ◽  
Quantitative Analyses ◽  
Single Determination ◽  
Acetone Peroxide ◽  
Qualitative Analyses

Abstract A quantitative and a qualitative method for the determination of acetone peroxides were subjected to collaborative study. Quantitative analyses are based upon liberation and titration of hydrogen peroxide from acyclic peroxides and hydroperoxides by dilute sulfuric acid and standardized potassium permanganate, respectively. Single determination of 6 samples (varying in per cent levels of peroxide equivalent) each of baking premixes and milling premixes produced very good collaborative results. Qualitative analyses, achieved by comparing infrared spectra of acetone-extracted organic peroxides with acetone-extracted organic peroxides from a reference premix, gave peaks characteristic of the premixes. No interferences were seen from various starch blanks. Both the quantitative and the qualitative methods are recommended for adoption as official, first action.

Determination of Maleic Hydrazide Residues in Tobacco and Vegetables

1973 ◽  
Vol 56 (5) ◽  
pp. 1164-1172
Author(s):  
Milan Ihnat ◽  
Robert J Westerby ◽  
Israel Hoffman
Keyword(s):  
Standard Deviation ◽  
Present Method ◽  
Maleic Hydrazide ◽  
Collaborative Study ◽  
Official Method ◽  
Sample Weight ◽  
Relative Standard ◽  
The Mean ◽  
Pipe Tobacco

Abstract The distillation-spectrophotometric method of Hoffman for determining maleic hydrazide has been modified to include a double distillation and was applied to the determination of 1–30 ppm maleic hydrazide residues in tobacco and vegetables. Recoveries of 1–23 μg added maleic hydrazide were independent of weight of maleic hydrazide, but did depend on sample and sample weight. The following recoveries were obtained from 0.5 g sample: pipe tobacco, 84%; commercially dehydrated potato, 83%; cigar tobacco, 81%; dried potato, 76%; fluecured tobacco, 73%; dried carrot, 71%. In the absence of sample, the recovery was 82%. When appropriate standard curves were used, maleic hydrazide levels determined in tobacco samples were essentially independent of sample weight in the range 0.1–3 g. The mean relative standard deviation for a variety of field-treated and fortified tobacco samples containing 1–28 ppm maleic hydrazide was 3%. The precision and sensitivity of this procedure seem to be substantial improvements over official method 29.111–29.117. It is recommended that the present method be subjected to a collaborative study.

Collaborative Study of Maleic Hydrazide Residue Analysis

1963 ◽  
Vol 46 (2) ◽  
pp. 261-268
Author(s):  
J R Lane
Keyword(s):  
Confidence Limit ◽  
Chemical Method ◽  
Maleic Hydrazide ◽  
Residue Analysis ◽  
Collaborative Study ◽  
Maximum Variation

Abstract With the Naugatuck Chemical Method G-114-A, an expanded laboratory version of the Lane, Gullstrom, and Newell modification of the original Wood method, five collaborators made distilled standard curves (10—200 μg) with maximum variation of + 10% and—4% from an average laboratory curve obtained over several years and with curves of maleic hydrazide distilled from potatoes with maximum variation of + 14% and—9%. Average recoveries of unknowns of duplicate determinations gave a 9 5% confidence limit of 13.5 μg at the 100 μg level, and 6.4 μg at the 25 μg level.

scholarly journals Determination of Vitamin B12 in Fortified Bovine Milk- Based Infant Formula Powder, Fortified Soya-Based Infant Formula Powder, Vitamin Premix, and Dietary Supplements by Surface Plasmon Resonance: Collaborative Study

2011 ◽  
Vol 94 (4) ◽  
pp. 1217-1226 ◽  
Author(s):  
Pathik Vyas ◽  
Anthony A O'kane ◽  
E Ager ◽  
S Crooks ◽  
C Elliott ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Protein Binding ◽  
Vitamin B12 ◽  
Infant Formula ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Binding Protein ◽  
Collaborative Study ◽  
Wide Range

Abstract A collaborative study was conducted on an inhibition-based protein-binding assay using the Biacore Q™ biosensor instrument and the Biacore Qflex™ Kit Vitamin B12 PI. The samples studied included infant formula, cereals, premixes, vitamin tablets, dietary supplements, and baby food. The collaborative study, which involved 11 laboratories, demonstrated that the assay showed an RSDr of 1.59–27.8 and HorRat values for reproducibility of 0.34–1.89 in samples with levels ranging from ppm to ppb. The assay studied is a label-free protein binding-based assay that uses the principle of surface plasmon resonance (SPR) to measure the interaction between vitamin B12 and a specifc binding protein. A Biacore Q biosensor uses this principle to detect binding directly at the surface of a sensor chip with a hydrophilic gold-dextran surface. The instrument passes a mixture of prepared sample extract and binding protein solution across a covalently immobilized vitamin B12 chip surface, and the response is given as free-binding protein as the mixture binds to the immobilized surface. This technique uses the specifcity and robustness of the protein-ligand interaction to allow minimal sample preparation and a wide range of matrixes to be analyzed rapidly. The reagents and accessories needed to perform this assay are provided as the ready-to-use format “Qflex Kit Vitamin B12 PI.” The method is intended for routine use in the quantitative determination of vitamin B12 (as cyanocobalamin) in a wide range of food products, dietary vitamin supplements, and multivitamin premixes.

Determination of the Iodine Value of Oils and Fats: Summary of Collaborative Study

1994 ◽  
Vol 77 (3) ◽  
pp. 674-676 ◽  
Author(s):  
David Firestone
Keyword(s):  
Acetic Acid ◽  
Iodine Value ◽  
Collaborative Study ◽  
Solvent Mixture ◽  
Acid Mixture ◽  
Collaborative Studies ◽  
Wide Range ◽  
Aoac Method ◽  
Iodine Values

Abstract Two collaborative studies were conducted using the Wijs method for determining the iodine value in a wide range of vegetable and animal oils and fats. The results obtained when using carbon tetrachlo-ride were compared to those obtained when using a substitute solvent mixture of cyclohexane and glacial acetic acid. The values reported for the iodine values indicate that the cyclohexane and acetic acid mixture can be used in place of carbon tetrachloride without loss of precision. The method has been adopted first action by AOAC INTERNATIONAL as an IUPAC/AOCS/AOAC method.

Relation between outer and luminal diameter in cannulated arteries

1999 ◽  
Vol 277 (5) ◽  
pp. H1745-H1753 ◽  
Author(s):  
Gilles Faury ◽  
Gail M. Maher ◽  
Dean Y. Li ◽  
Mark T. Keating ◽  
Robert P. Mecham ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Experimental Conditions ◽  
Cross Sectional ◽  
Luminal Diameter ◽  
Fluorescent Marker ◽  
Wide Range ◽  
Before And After ◽  
Single Determination ◽  
Knockout Animals

Resistance in blood vessels is directly related to the inner (luminal) diameter (ID). However, ID can be difficult to measure during physiological experiments because of poor transillumination of thick-walled or tightly constricted vessels. We investigated whether the wall cross-sectional area (WCSA) in cannulated arteries is nearly constant, allowing IDs to be calculated from outer diameters (OD) using a single determination of WCSA. With the use of image analysis, OD and ID were directly measured using either transillumination or a fluorescent marker in the lumen. IDs from a variety of vessel types were calculated from WCSA at several reference pressures. Calculated IDs at all of the reference WCSA were within 5% (mean <1%) of the corresponding measured IDs in all vessel types studied, including vessels from heterozygote elastin knockout animals. This was true over a wide range of transmural pressures, during treatment with agonists, and before and after treatment with KCN. In conclusion, WCSA remains virtually constant in cannulated vessels, allowing accurate determination of ID from OD measurement under a variety of experimental conditions.

Determination of Minerals and Trace Elements in Milk, Milk Products, Infant Formula, and Adult Nutrition: Collaborative Study 2011.14 Method Modification

2019 ◽  
Vol 102 (6) ◽  
pp. 1845-1863
Author(s):  
Hans Cruijsen ◽  
Eric Poitevin ◽  
Sharon L. Brunelle
Keyword(s):  
Trace Elements ◽  
Infant Formula ◽  
Dairy Products ◽  
Collaborative Study ◽  
Milk Powder ◽  
Emission Spectrometry ◽  
Official Method ◽  
Wide Range ◽  
Low Levels

Official MethodSM 2011.14/ISO 15151:2018/IDF 229:2018 uses microwave digestion of samples and inductively coupled plasma–atomic emission spectrometry for determination of nine elements, including Ca, Cu, Fe, K, Mg, Mn, Na, P, and Zn. The method was evaluated in a collaborative study of 25 products, including 13 fortified nutritional products (powders, ready-to-feed liquids, and liquid concentrates), five product placebos, six dairy products (liquids, powders, butter, and processed cheese), and the National Institute for Standards and Technology (NIST) Standard Reference Material (SRM) 1849a, in compliance with AOAC INTERNATIONAL Standard Method Performance Requirement (SMPR®) 2014.004. This study significantly expanded the applicability of Official Method 2011.14 beyond the original scope of chocolate milk powder, dietetic milk powder, infant cereal, peanut butter, and wheat gluten. The study included 14 collaborators from 11 countries, and results were compared to SMPR 2014.004. Accuracy of the method was demonstrated using NIST SRM 1849a, yielding recoveries across all laboratories of 98–101% for the nine elements. Precision for the 13 fortified nutritional product samples was 2.2–3.9% for repeatability (relative SD of repeatability) and 6.0–12.2% for reproducibility (RSDR). Excluding Mn, which was present at a wide range of concentrations, the reproducibility was 6.0–9.5%, meeting the performance requirements of SMPR 2014.004. Placebo samples (not fortified with Cu, Fe, Mn, or Zn) yielded acceptable repeatability of 1.8–2.9% for Ca, K, Mg, Na, and P (minerals) but 5.4–29.4% for the low levels of Cu, Fe, Mn, and Zn (trace elements). Reproducibility for the placebos showed the same pattern, with acceptable reproducibility (5.4–10.3%) for minerals but not for the low levels of the trace elements (13.2–82.8%). In the six dairy product samples, repeatability ranged from 1.6 to 3.6% for the minerals, Zn, and the low range of Mn but from 9.4 to 24.6% for Cu, Fe, and the high range of Mn, where concentrations were low as for the nutritional placebos. Reproducibility in the dairy samples was 5.3–8.8% for the minerals but 11.4–55.0% for the trace elements. The mean concentrations of Cu, Fe, and Zn in the dairy products were similar with those in the placebo products, while Zn was present at levels more similar with the fortified nutritional products. Thus, the method met the SMPR criteria except where the trace minerals were present at very low levels. Based on these results, the AOAC Stakeholder Panel for Infant Formula and Adult Nutritionals recommended Final Action status of the expanded applicability of the method. The method was adopted as Final Action by the AOAC Official Methods Board.

Collaborative Study of a Spectrophotometric Method for Determining Maleic Hydrazide Residues in Tobacco and Vegetables

1975 ◽  
Vol 58 (6) ◽  
pp. 1235-1243
Author(s):  
Milan Ihnat ◽  
Brian Thompson
Keyword(s):  
Standard Deviation ◽  
Spectrophotometric Method ◽  
Strong Evidence ◽  
Maleic Hydrazide ◽  
Collaborative Study ◽  
Green Bean ◽  
F Test ◽  
Coefficients Of Variation ◽  
Better Than

Abstract A distillation-spectrophotometric method for the determination of maleic hydrazide residues in tobacco and vegetables reported previously was studied collaboratively. Ten laboratories submitted analytical results on 10 samples containing residues resulting either from field treatment or laboratory fortification. The samples were estimated to contain from 0.99 to 16.36 μg maleic hydrazide/0.5 g sample analyzed. The coefficients of variation based on precision standard deviation ranged from 57.7% for the lowest residue content to 32.4% for the highest. The corresponding coefficients of variation based on overall standard deviations were estimated to be at least one-fifth larger. Strong evidence of systematic laboratory differences was found (F-test, significant at 0.1%). Apparent recoveries of 10.0 fifl maleic hydrazide added to 0.5 g fluecured tobacco and potato were 97.3 and 89.7%, respectively. Apparent recoveries of 16.0 and 16.5 μg added to 0.5 g green bean were 87.4 and 85.5%, respectively. The precision of the method studied was no better than that of the current official final action method, 29.121–29.127, and its adoption is not recommended.

scholarly journals Determination of Hydrazine in Maleic Hydrazide Technical and Pesticide Formulations by Gas Chromatography: Collaborative Study

2008 ◽  
Vol 91 (1) ◽  
pp. 5-12 ◽  
Author(s):  
Anthony S Riggs ◽  
David M Borth ◽  
David G Tutty ◽  
Wan S Yu ◽  
B Barclay ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Gas Chromatography ◽  
Electron Capture ◽  
Maleic Hydrazide ◽  
Collaborative Study ◽  
Test Sample ◽  
Electron Capture Detection ◽  
Pesticide Formulations ◽  
Liquid Concentrate

Abstract Twelve collaborating laboratories assayed hydrazine in technical maleic hydrazide (MH), 6-hydroxy-2H-pyridazin-3-one, and 2 formulated products, a liquid concentrate and a soluble granule, using gas chromatography (GC) with electron capture detection. The hydrazine content in the samples ranged from 0.03 ppm, in the liquid concentrate, to 0.26 ppm, in MH technical. Hydrazine and MH are dissolved in an aqueous solution. The MH is then precipitated out of solution by acidification. The solution containing hydrazine is treated with excess pentafluorobenzaldehyde (PFB) to form pentafluorobenzaldehyde azine (PFBA). The PFBA is extracted with hexane for analysis by GC using an electron capture detector. Peak area responses of PFBA are measured and quantified by external standardization. Hydrazine concentration is calculated from the PFBA determination. The laboratories weighed each test sample in duplicate with duplicate analysis for each weighing. Data from these laboratories were statistically analyzed. The average relative repeatability was determined to be 5.34 and the average relative reproducibility was 27.99.

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