James T. Tanner

Preparation of a mixed human diet material for the determination of nutrient elements, selected toxic elements and organic nutrients: A preliminary report

Using 201 foods from the United States Food and Drug Administrations Total Diet Study (FDA TDS), a mixed diet composite (USDIET-I) was prepared to represent the intake of 25-30-year-old males in the United States. Proximate analyses, phytate determination, and assays for nutrient elements and selected toxic elements, as well as organic nutrients were carried out on this composite. As part of a quality control exercise for a coordinated research program, atomic absorption spectrophotometry, inductively coupled atomic emission spectrometry, colorimetry and neutron activation analysis were used to determine up to 30 elements in this diet material. A comparison of the daily intakes of As, Ca, Cd, Cu, Fe, Hg, K, Mg, Mn, Na, P, Se and Zn from the composite USDIET-I shows excellent to good agreement with FDA TDS values calculated from results of single food analyses. These USDIET-I results demonstrate the feasibility of the mixed diet concept as a viable approach for a reliable assessment of daily intakes, especially for a number of elements such as Cd, Cr, Hg and Mo that occur at low concentrations in individual food products. Simultaneously, stability of some organic nutrients during storage was also investigated. Initial findings suggest that this program may also be useful in the development of reference materials for organic nutrients, for which there is a great need. These aspects are discussed.

MERCURY CONTENT OF COMMON FOODS DETERMINED BY NEUTRON ACTIVATION ANALYSIS.

The mercury contents in samples of flour, sugar, nonfat dry milk, potatoes, hamburger, chicken breast, shrimp, liver, eggs, and whole milk were determined by neutron activation analysis. The mercury was separated by anion exchange chromatography and precipitated as the sulfide. The mercury concentrations for all these foods were below 50 parts per billion.

The toxicity of brominated sesame oil and brominated soybean oil in miniature swine

Miniature swine were fed brominated sesame oil at dietary levels of 0, 5, 25, 50 or 500 mg/kg of body weight for 17 weeks and brominated soybean oil at levels of 0, 5, 50 or 500 mg/kg of body weight for 28 weeks. Growth rate and food intake were decreased only at the high dose level in the brominated sesame oil study. In both studies, signs of lethargy and ataxia occurred in pigs fed the highest dose, and were probably due to a dose-related increase in serum bromine concentrations. Marked elevations in lactic dehydrogenase (LDH), serum glutamic-oxalacetic transaminase (SGOT) and serum glutamicpyruvic transaminase (SGPT) values were seen at the highest dose level with both substances and these enzyme activities were increased at the 50 mg/kg dose level in the brominated sesame oil study. Histopathologic lesions were confined to animals given the highest dose level of either oil. Marked fatty degeneration of the hepatic plate cells and renal tubular epithelial cells were seen in both studies. In the brominated sesame oil study, neutral fat was moderately increased in the myocardium of the pigs fed 500 mg/kg. However, marked diffuse accumulation of LDH, marked diffuse fatty degeneration and focal degeneration, and/or necrosis of individual or small groups of cardiac muscle fibers were seen in the group fed brominated soybean oil at 500 mg/kg. A moderate to marked testicular atrophy was also observed in this group. A dose-related accumulation of total and hexane-soluble bromine was observed in all tissues examined in both studies; the highest concentrations occurred in adipose tissue of the pigs given the highest dose level. Kidneys, livers, hearts and thyroids of these groups also contained large amounts of bromine. In pigs given the 50 mg/kg dose level, total and hexane-soluble bromine concentrations were higher in the brominated sesame oil study than in the longer brominated soybean oil study and may be responsible for the elevations in LDH, SGPT and SGOT activities in this group.

Instrumental neutron activation analysis for bromine in pig tissues

Abstract Bromine was determined by instrumental neutron activation analysis in tissues and organs of pigs as an indicator of brominated vegetable oil residues. The bromine content was found to be dose-related. An advantage of this technique is that the sample was not treated chemically. The analyses were done with the aid of an automatic sample changer and computer reduction of the data. Rapid and reliable analyses were obtained at the p.p.m. level.

Mixed diet reference materials for nutrient analysis of foods: Preparation of SRM-1548 Total Diet

SummarySeveral mixed component diet materials have been available for use as reference materials for determination of elemental contents in food. These included H-9, issued by the IAEA and RM-8431, issued by NIST. Wide acceptance of these materials has exhausted supplies and they are no longer available. A new mixed food Standard Reference Material, SRM-1548 Total Diet, has been prepared and characterized for a number of elemental and organic constituents. This material was prepared from foods obtained from collections of the US FDAs Total Diet Study, which are representative of foods consumed by the US population. SRM-1548 has been composited from these foods, in proportions that are representative of daily intake. The composited foods were blended, freeze-dried, reblended and bottled in portions of 6 g. Homogeneity studies were carried out along with certification analyses for elements, cholesterol proximate and caloric content. This material is available from NIST and will be useful as a multi-purpose SRM for determinations of constituents in the naturally occurring range in foods and food related materials. Since this is a mixture of foods of both good and poorer sources, levels will be at the lower end of the concentration range for any individual constituent. Availability of further SRMs of individual foods with higher levels of specific constituents, such as SRM-1845 Cholesterol in Whole Egg will be required to extend the range of certified concentration values for food reference materials.

Multipurpose biological reference materials

SummaryReference materials to meet multipurpose needs for analysis of both inorganic and organic constituents in biological investigations are not readily available. A human total diet material is being investigated as a reference material for a wide variety of constituents of interest to human nutrition and health. This material shows a stable assay value for the natural levels of a number of vitamins following freeze-drying or radiation sterilization. This is an important feature in producing materials for long term stability as a Reference Material for natural levels of these constituents. An exception is an increase of 34% in assay value of folic acid upon freeze-drying and an 85% increase upon freezedrying followed by radiation sterilization.

The determination of antimony in standard rocks by instrumental neutron activation analysis

Abstract The abundance of antimony in the standard rocks G-l, W-l, G-2, BCR-1, AGV-1, PCC-1, DTS-1, GSP-1, SUL-1, SYE-1, BCR-2 and GR has been determined by instrumental neutron activation analysis. Comparison of the results of this work with those previously reported indicate that DTS-1 is the best choice as an antimony standard. Results for SYE-1, G-1 and AGV-1 indicate that these standards may not be sufficiently homogeneous.

Determination of mercury in total diet samples by neutron activation

Abstract The mercury contents of food samples representative of the total diet have been determined by neutron activation analysis. The mercury was separated by anion-exchange chromatography and precipitated as the sulfide. The mercury concentrations for the different fractions of total diet samples were well below 50 p.p.b. Only in the meat, fish, and poultry fraction were measurable amounts of mercury encountered regularly.

Arsenic and antimony in laundry aids by instrumental neutron activation analysis

>The measurement of trace amounts of arsenic and antimony in laundry aids by neutron activation analysis is described. The results for arsenic are compared with those obtained by other analytical techniques. The concentratlons ln the various laundry aids tested ranged from 5 to 51 ppM of arsenic and from 1 to 8 ppM of antimony. (auth)