Determination of Low Levels of Mite and Insect Contaminants in Food and Feedstuffs by a Modified Flotation Method

Abstract Extraneous material was separated from feed and food products by a modified technique in which kerosene is used in a specially designed flotation flask. This technique, although effective for analyzing feed and foods, presented limitations in the analysis of finely powdered materials. Some procedural modifications and an increased in the capacity of the flotation flask from 500 to 750 mL allowed a larger sample weight (20 g) to be analyzed for mites, insect fragments, and rodent hairs, with considerably reduced residue interference. In trials with a variety of products seeded with known numbers of mites, average recovery was 83%. Recoveries of 89% were obtained from flour samples seeded with insect fragments and rodent hairs. A new process of suspending extracted mites in a mixture of industrial methylated spirit (46%) and glycerol (54%) by volume was used to allow rapid and more precise estimates of mite populations in heavily infested samples.

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Applicability of an Isotope Exchange Method for the Determination of Milligram and Microgram Quantities of Organic Mercurials. I. Pharmaceutical and Agricultural Mercurials

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/48.6.1134 ◽

1965 ◽

Vol 48 (6) ◽

pp. 1134-1138

Author(s):

Sidney Davis ◽

Alphonso Arnold

Keyword(s):

Isotope Exchange ◽

Mercury Determination ◽

Exchange Method ◽

Average Recovery ◽

Low Levels ◽

Standard Techniques ◽

Isotope Exchange Method ◽

Organic Mercurials ◽

Exchange Technique

Abstract The isotope exchange technique was applied to the analysis of milligram and microgram quantities of organic mercurials, with emphasis on pharmaceuticals and fungicides of an agricultural nature. Average recovery was 98.48 ± 1.12% for Hg-203 in equilibrium with chemical mercury. In comparison studies, the isotope exchange procedure showed essential agreement with standard techniques for mercury determination. At low levels, traces of mercury via glassware contamination were observed to interfere. The digestion system was found to be applicable to most organic mercurials studied except ethyl mercuric phosphate and three commercial fungicides.

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Determination of Low Levels of Cadmium in Foods Using a Chelating Ion Exchange Resin

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/57.1.14 ◽

1974 ◽

Vol 57 (1) ◽

pp. 14-17

Author(s):

Richard A Baetz ◽

Charles T Kenner

Keyword(s):

Ion Exchange ◽

Extraction Method ◽

Exchange Resin ◽

Atomic Absorption Spectrophotometry ◽

Ion Exchange Resin ◽

Average Recovery ◽

Digestion Procedure ◽

Absorption Spectrophotometry ◽

Low Levels

Abstract A method is described for the determination of cadmium in foods which utilizes the AOAC HN03, H2S04, H202 digestion procedure catalyzed by V2O5. The cadmium is separated from the neutralized digest by a chelating ion exchange resin, eluted with H2S04, and determined by atomic absorption spectrophotometry. The average recovery of 0.30 ppm cadmium added to 7 commodities was 94% with a standard deviation of 2.8%, which compares favorably with the AOAC dithizone extraction method. The transfer, washing, and elution of 6 samples by the proposed method requires approximately 2 hr. The method allows the determination of as little as 10 ppb cadmium.

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Greek Graviera Cheese Assessment through Elemental Metabolomics—Implications for Authentication, Safety and Nutrition

Molecules ◽

10.3390/molecules24040670 ◽

2019 ◽

Vol 24 (4) ◽

pp. 670 ◽

Cited By ~ 5

Author(s):

Georgios Danezis ◽

Charis Theodorou ◽

Theofilos Massouras ◽

Evangelos Zoidis ◽

Ioannis Hadjigeorgiou ◽

...

Keyword(s):

Geographic Origin ◽

Precious Metals ◽

Cow Milk ◽

Linear Discriminant ◽

Low Levels ◽

Almost All ◽

Sample Set ◽

Larger Sample ◽

Type Classification

This study presents the comprehensive elemental profile of Greek Graviera (Gruyère) cheeses. In total, 105 samples from nine different geographic regions produced from sheep, goat and cow milk and their mixtures were assessed. Elemental signatures of 61 elements were investigated for determination of geographic origin and milk type. Regional and milk type classification through Linear Discriminant Analysis was successful for almost all cases, while a less optimistic cross validation exercise presented lower classification rates. That points to further research using a much larger sample set, increasing confidence for cheese authentication utilizing also bioinformatics tools under development. This is the first study reporting signatures of 61 elements in dairy products including all sixteen rare earth elements and all seven precious metals. Safety and quality were assessed regarding toxic and nutritive elements. According to both EU and USA regulations and directives, Graviera is a nutritional source for trace and macro elements with low levels of toxic elements.

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Collaborative Study of a Method for Determination of Monosodium Glutamate in Food Products

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/52.6.1131 ◽

1969 ◽

Vol 52 (6) ◽

pp. 1131-1132

Author(s):

E Fernandez-Flores ◽

Arthur R Johnson ◽

Victor H Blomquist

Keyword(s):

Standard Deviation ◽

Glutamic Acid ◽

Monosodium Glutamate ◽

Collaborative Study ◽

Food Products ◽

Average Recovery

Abstract A method was collaboratively studied for the determination of monosodium glutamate as glutamic acid in food products. Six samples were submitted to each of nine collaborators. The quantity of monosodium glutamate in the samples ranged from 0.3 to 10%. The average recovery was 101.9% with a standard deviation of 3.6%. The method is recommended for adoption as official first action.

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Liquid Chromatographic Determination of N-Methylcarbamate Insecticides and Metabolites in Crops. II. Analytical Characteristics and Residue Findings

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/68.4.734 ◽

1985 ◽

Vol 68 (4) ◽

pp. 734-741

Author(s):

Richard T Krause

Keyword(s):

Food Products ◽

Chromatographic Determination ◽

Compound A ◽

Average Recovery ◽

Carbamate Insecticides ◽

Liquid Chromatographic Method ◽

Liquid Chromatographic Determination ◽

Food Commodities ◽

Liquid Chromatographic

Abstract Four laboratories obtained 177 carbamate recovery values using a liquid chromatographic method. The average recovery of 11 carbamates (aldicarb, aldicarb sulfone, bufencarb, carbaryl, carbofuran, 3- hydroxy carbofuran, 3-keto carbofuran, methiocarb, methiocarb sulfoxide, methomy 1, and oxamyl) from 14 crops was 99% with a coefficient of variation of 8% (0.03-1.8 ppm fortification levels). No statistical difference in recovery was found between oxime and phenyl carbamates, or between parent and metabolite carbamates. Average recovery of aldicarb sulfoxide was 59% due to loss in the liquid-liquid partitioning because of the polarity of this compound. A fifth laboratory contributed 34 carbamate recoveries (average 99%) on table-ready food products for 4 carbamates. Bendiocarb, dioxacarb, isoprocarb, and propoxur are also quantitatively recovered through the method. Previously reported carbamate and noncarbamate recovery data are also discussed. In the Food and Drug Administration's (FDA) analysis of 319 samples (mainly crops), 86 (27%) were found to contain residues of carbamate insecticides and/or toxic carbamate metabolites. Carbaryl and methomyl were the most common carbamate residues found on the food products excluding the aldicarb sulfone and sulfoxide residues found on potatoes. In one FDA Total Diet Program "market basket", 11 of 69 table-ready food commodities contained from 0.005 to 0.094 ppm carbamate residues. Carbaryl was the most prevalent residue. Several laboratories reported adverse effects on the determinative system when inadequately purified reagents were used.

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Determination of Trace Amounts of Nitrites in Fabricated Nonmeat Products

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/64.1.226 ◽

1981 ◽

Vol 64 (1) ◽

pp. 226-227

Author(s):

Anthony Desiena ◽

Emma Jacobs ◽

Ronald Romagnoli

Keyword(s):

Vegetable Oils ◽

Raw Materials ◽

Food Products ◽

Soy Proteins ◽

Processed Meats ◽

Aoac Method ◽

Hydrogenated Vegetable Oils ◽

Low Levels ◽

Composite Samples

Abstract Low levels of nitrite (1-5 ppm) contributed by raw materials in new fabricated food products were successfully determined by a modification of an AOAC method for processed meats. Recoveries were greater than 90% for composite samples to which 5-10 ppm nitrite had been added. This method allows analyses of fabricated food products containing hydrogenated vegetable oils, soy proteins, and dried egg whites for low levels of nitrite.

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Determination of quaternary ammonium compounds in food products by the method of ultra-performance liquid chromatography/high resolution mass-spectrometry

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2020-86-8-23-31 ◽

2020 ◽

Vol 86 (8) ◽

pp. 23-31

Author(s):

V. G. Amelin ◽

D. S. Bolshakov

Keyword(s):

Mass Spectrometry ◽

High Resolution ◽

Quaternary Ammonium ◽

High Resolution Mass Spectrometry ◽

Food Products ◽

Quaternary Ammonium Compounds ◽

High Resolution Mass ◽

Ammonium Compounds ◽

Resolution Mass

The goal of the study is developing a methodology for determination of the residual amounts of quaternary ammonium compounds (QAC) in food products by UHPLC/high-resolution mass spectrometry after water-acetonitrile extraction of the determined components from the analyzed samples. The identification and determination of QAC was carried out on an «UltiMate 3000» ultra-high-performance liquid chromatograph (Thermo Scientific, USA) equipped with a «maXis 4G» high-resolution quadrupole-time-of-flight mass spectrometric detector and an ion spray «ionBooster» source (Bruker Daltonics, Germany). Samples of milk, cheese (upper cortical layer), dumplings, pork, chicken skin and ground beef were used as working samples. Optimal conditions are specified for chromatographic separation of the mixture of five QAC, two of them being a mixture of homologues with a linear structure (including isomeric forms). The identification of QAC is carried out by the retention time, exact mass of the ions, and coincidence of the mSigma isotopic distribution. The limits for QAC detection are 0.1 – 0.5 ng/ml, the determination limits are 1 ng/ml for aqueous standard solutions. The determinable content of QAC in food products ranges within 1 – 100 ng/g. The results of analysis revealed the residual amount of QAC present in all samples, which confirms data of numerous sources of information about active use of QAC-based disinfectants in the meat and dairy industry. The correctness of the obtained results is verified by introduction of the additives in food products at a level of 10 ng/g for each QAC. The relative standard deviation of the analysis results does not exceed 0.18. The duration of the analysis is 30 – 40 min.

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