Determination of iron in milk and other biological materials

Stugart, Ralph

doi:10.1021/ac50076a028

Cited by 54 publications

(13 citation statements)

References 7 publications

(10 reference statements)

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“…Amyl alcohol was used to extract the iron thiocyanate color in preference to the more volatile ether, acetone, and ethylacetate (16). The red color of iron thiocyanate was found to be stable in amyl alcohol solutions for at least fifteen minutes, so that there was ample time in which to make the colorimetric comparisons.…”

Section: The Determination Of Plasma and Serum Ironmentioning

confidence: 99%

Studies in Iron Transportation and Metabolism. I. Chemical Methods and Normal Values for Plasma Iron and “Easily Split-Off” Blood Iron

Moore¹,

Arrowsmith²,

Quilligan³

et al. 1937

J. Clin. Invest.

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Section: The Determination Of Plasma and Serum Ironmentioning

confidence: 99%

Studies in Iron Transportation and Metabolism. I. Chemical Methods and Normal Values for Plasma Iron and “Easily Split-Off” Blood Iron

Moore¹,

Arrowsmith²,

Quilligan³

et al. 1937

J. Clin. Invest.

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“…With dried fruits (6) a dry-ashing was followed by a determination of the iron using the colorimetric thiocyanate method of Stugart (6). In early studies on fruit juices and wines (4) essentially the colorimetric mercaptoacetic acid method of Lyons (3) and Leavell and Ellis (a), with sulfuric and perchloric acid wet-ashing, was used.…”

mentioning

confidence: 99%

Determination of Iron: Colorimetric o-Phenanthroline Method

Saywell¹,

Cunningham²

1937

Ind. Eng. Chem. Anal. Ed.

257

100

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K THE determination of the iron content of various fruit I products and materials utilized in their production, two methods have been used previously by the authors. With dried fruits (6) a dry-ashing was followed by a determination of the iron using the colorimetric thiocyanate method of Stugart (6). In early studies on fruit juices and wines (4) essentially the colorimetric mercaptoacetic acid method of Lyons (3) and Leavell and Ellis (a), with sulfuric and perchloric acid wet-ashing, was used. The latter methods were also used in a study of certain filter aids and asbestos filtering products.The dry-ashing and Stugart procedure require considerable time, so that where several hundred determinations are to be made, a more rapid and simple, yet accurate, method is desirable. For over 2 years an adaptation of the wet-ashing method of Leavell and Ellis has been successfully employed with the usual ashing times of 3 to 7 hours for wines and many fruit juices reduced to periods of 2 to 10 minutes for each sample.Because of the difficulty in color comparison with concentrations lower than 2 or 3 parts per million (p. p. m.) and the occasional fading of the mercaptoacetic acid colored complex, it appeared desirable to have a method of equal or greater sensitivity and accuracy, with a higher degree of precision. ExperimentalIt has been pointed out by Walden, Hammett, and Chapman (7) that the ferrous o-phenanthroline complex ion discovered by Blau (1) may be used as a reversible oxidation indicator of high potential. The ferrous complex gives an intense red color.The authors have observed that the color, when once formed in slightly acid to neutral solutions, is very stable and standards have been kept for over 4 months without exhibiting differences from freshly prepared standards, Solutions containing a final iron concentration of 1 to 10,000,000 give color of sufficient intensity for colorimetric comparison. For iron concentrations of the same magnitude, the intensity of the color is proportional t o the iron content. Concentrations of greater than 20 or 25 p. p. m. may be conveniently diluted by one-half, or smaller samples may be taken for analysis.As the iron in the strongly acid solution remaining from the wet-ashing is in the ferric condition, reduction to the ferrous condition before the addition of the o-phenanthroline is necessary. Several reducing agents were studied, the best being sodium hypophosphite or hypophosphorous acid, and sodium formate, which were discontinued because of the considerable iron content of these products and the necessary correction therefor. The use of a concentrated solution of iron-free hydroxylamine hydrochloride has been adopted.Numerous experiments were made to ascertain the most satisfactory procedure and conditions for the addition of the reagents, As a result it was observed that a treatment of the warm acid solution (remaining from the wet-ashing) with hydroxylamine, followed by the addition of o-phenanthroline and neutralization with concentrated ammonium

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“…Chemical methods approved by the Association of Official Agricultural Chemists (1940) were used for all the determinations except iron, which was analyzed by Stugart's (1931) method modified as follows: (1) The colored iso-amyl alcohol layer was washed with 25 milliliters of a five-per cent solution of potassium sulfocyanide saturated with iso-amyl alcohol.…”

Section: Methodsmentioning

confidence: 99%

NUTRITIVE VALUE OF CANNED FOODS. XVI. PROSIMATI AND MINERAL COMPOSITION¹

Kramer¹

1946

Journal of Food Science

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This work was undertaken as an integral part of the National Canners Association-Can Manufacturers Institute Nutrition program, in order to obtain a more thorough knowledge of the proximate and mineral composition of canned foods. A total of 1,384 samples, collected during the canning seasons of 1942 and 1943, were analyzed. The methods used by the nutrition committee in selecting the various foods, their geographical distribution, and methods of preparation of the 1942 samples have been described in detail by Clifcorn (1944). The methods of collecting samples during the 1943 season were similar to those of the previous year except that the following additional foods were included : blackberries, blueberries, cherries, cream style corn, kraut, mushrooms, peppers, pimentos, sweet potatoes, and turnip greens. MATERIALS AND METHODSThe total contents of four or six retail size cans or one to three No. 10 size cans comprising each sample were combined and thoroughly macerated in a Waring blendor. Portions of the uniformly blended mixture were then removed for the chemical analyses.Chemical methods approved by the Association of Official Agricultural Chemists (1940) were used for all the determinations except iron, which was analyzed by Stugart's (1931) method modified as follows: (1) The colored iso-amyl alcohol layer was washed with 25 milliliters of a five-per cent solution of potassium sulfocyanide saturated with iso-amyl alcohol.(2) A per cent transmittance curve was prepared by plotting the per cent transmittance on a spectrophotometer a t 490 millimicrons for a series of known solutions of pure iron. Per cent transmittance a t 490 millimicrons was then obtained for each sample, and the amount of iron calculated by reference to the standard curve. RESULTSI n a survey investigation of this nature, the average figures are of the greatest value since they indicate the average composition of the commodities as they are prepared under the variable conditions prevailing in different sections of the country and during different seasons and years; the results are summarized (Table 1 ) .

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Determination of iron in milk and other biological materials

Cited by 54 publications

References 7 publications

Studies in Iron Transportation and Metabolism. I. Chemical Methods and Normal Values for Plasma Iron and “Easily Split-Off” Blood Iron

Studies in Iron Transportation and Metabolism. I. Chemical Methods and Normal Values for Plasma Iron and “Easily Split-Off” Blood Iron

Determination of Iron: Colorimetric o-Phenanthroline Method

NUTRITIVE VALUE OF CANNED FOODS. XVI. PROSIMATI AND MINERAL COMPOSITION¹

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Determination of iron in milk and other biological materials

Cited by 54 publications

References 7 publications

Studies in Iron Transportation and Metabolism. I. Chemical Methods and Normal Values for Plasma Iron and “Easily Split-Off” Blood Iron

Studies in Iron Transportation and Metabolism. I. Chemical Methods and Normal Values for Plasma Iron and “Easily Split-Off” Blood Iron

Determination of Iron: Colorimetric o-Phenanthroline Method

NUTRITIVE VALUE OF CANNED FOODS. XVI. PROSIMATI AND MINERAL COMPOSITION1

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NUTRITIVE VALUE OF CANNED FOODS. XVI. PROSIMATI AND MINERAL COMPOSITION¹