Haruo Tsuji

Longitudinal study on selenium content in human milk particularly during early lactation compared to that in infant formulas and cow's milk in Japan

239 samples of human breast milk were collected from 36 healthy Japanese women. Selenium content of the samples was determined mainly by highly sensitive fluorometric analysis with 2,3-diaminonaphthalene. The highest selenium content, 247 micrograms/kg, was found on the first day postpartum. The arithmetic mean of selenium content was higher in colostrum (< 4 days) 47 micrograms/kg (SD 42, n = 116) than in transitional milk 24 micrograms/kg (SD 13, n = 87) or in mature milk (> 10 days) 10 micrograms/kg (SD 4, n = 36). Selenium content was also determined for six brands of commercial infant formula powder (32-58 micrograms/kg) based on cows milk, seventeen brands of cows milk (10-25 micrograms/kg) and eight brands of powered cream for cofee (9-162 micrograms/kg). The average selenium content was significant lower in the liquid formula prepared for infant lactation, 6.0 micrograms/L, than in the human colostrum and transitional milk. The dietary selenium intake of newborns fed on colostrum is estimated to be in the range of 2-12 micrograms per day.

Radioactivation analysis of hair a means of biological monitoring of the environment

With the aim of indicating environmental pollution effects by heavy metals on humans using hair, nondestructive activation analysis was applied to 382 normal Japanese hair samples (background level). Elemental contents of hair could be determined for Ag, Al, As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, I, K, La, Mg, Mn, Na, S, Sb, Sc, Se, Sm, Ti, V and Zn. As these elements in hair have wide concentration ranges, the differences in concentrations distribution between groups (sex, age, permanent treatment and regional difference) are discussed. A method for hair sampling is presented.

Separation of bisphenol A and three alkylphenols by micellar electrokinetic chromatography.

Analytical conditions of pH, surfactants, and additives were investigated for the simultaneous separation of bisphenol A and alkylphenols by micellar electrokinetic chromatography. Reproducibility of migration time was improved at higher pH (pH 8.0). When five surfactants having linear alkyl chains or four bile salts were used, the separation of hydrophobic phenols and 4-nonylphenol isomers was not achieved. In order to improve the separation, the use of additives with sodium dodecyl sulfate solution was investigated. The separation of hydrophobic phenols was improved by the addition of organic solvents, however, isomers were not separated. Their separation was achieved by the addition of beta- or gamma-cyclodextrin.

Neutron activation analysis of biologically essential trace elements in environmental specimens using pyrrolidinedithiocarbamate extraction

A new radiochemical group separation method using APDC reagent in the extraction procedure has been developed. The method has been applied to the radiochemical separation for activated biological samples and also to the preconcentration technique for sea water samples. The transition elements are extracted into chloroform phase from the pH 3.0 aqueous phase and only manganese is subsequently extracted from the pH 7.0 aqueous phase. The validity of the method is demonstrated by analyzing the NBS standard reference materials. In the specimens preconcentrated from the sea water samples adjusted pH to 5.5, vanadium, manganese, copper and zinc can be determined.

Multielement analysis of groundwater samples by neutron activation with comparison between direct and evaporation methods

This report is the results of the studies on NAA of groundwater samples with comparison between direct and evaporation methods, and of the applications for the samples of alluvium plain composed with granitiform soils and of Neogene strata composed with clay minerals.

Emission spectrographic determination of trace elements in atmospheric particulate matter

Abstract Air containing particulate material was passed continuously for one month through a low-volume air sampler equipped with a cyclone to exclude particulates greater than 10 μm in diameter. The samples and filters were ashed in a low-temperature plasma and, after addition of In2O3 support, palladium internal standard and graphite buffer, the ashes were analyzed by a.c. are emission spectrometry. Standard samples were prepared from a commercial standard containing 49 elements. The procedure allows the determination of 14 trace metals (Ag, Al, Cr, Cu, Fe, Ga, Mn, Mo, Ni, Pb, Sn, Ti, V, Zn) with relative standard deviations of 1.4–15.1%. The procedure has been applied successfully to monthly determinations of the average atmospheric concentrations of these elements in Kobe City for the past three years.

Selenium Intake for Infants Immediately After Delivery

Abstract Selenium content of colostral milk and mature milk in 5 months after birth was determined by fluorometry with 2,3- diaminonaphthalene. In the first milk after birth selenium was contained to be the highest amounts of 29.4 ng/g but selenium concentration decreased to about 9 ng/g after the birth of 1 week. In the lactation period of 10 to 171 days, the concentration was almost constant to be 9.0 ± 1.2 ng/g. The content of infant formulas (milk powder for young infants) based on cows milk was 42.9 ± 8.4 ng/g corresponding to 6.0 ± 1.2 ng/ml in the liquid milk prepared for lactation. Therefore selenium intake was calculated to be about 17 μg/d in the colostral milk-feeding infants after delivery and about 8 μ g/d in mature milk-feeding infants at the age of more than 1 month after birth, whereas it was 3 -6 μ g/d in formula-feeding infants.