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Abstract. The present work describes an analytical procedure for the determination of the total iodine content in biological materials (serum, milk, plants, tissues etc.). Liquid samples can be directly analyzed after dilution, if necessary, by ICP-MS. Milk powder, plants and tissues were dissolved by using a modified simple SchSninger combustion, subsequently the residue was taken up in 0.1 mol/1 NaOH and this solution was analyzed by ICP-MS. The detection limit is in the range of 0.01 #g/1. The method was tested using different CRMs certified for the iodine content.

The concentrations of the trace elements Cd, Hg, Pb, and Se during the perinatal period in human placenta and in the blood of the mother and the newborn (cord blood) were determined. Breast milk (colostrum and mature milk) was also included to permit correlations between the different compartments. For Cd, a placental barrier exists, in accord with previous observations. For Pb, a strong correlation between the concentrations in the blood of the mother and of the newborn was found. The concentration of Hg was in most cases below the detection limit. Its concentration in colostrum was higher than in the mature milk. The results for Se reflect the knowledge about an essential trace element. Strong positive correlations were noted between maternal blood and cord blood and maternal milk. Anodic stripping voltammetry (DPASV) was used for the determination of Cd and Pb, cold vapor AAS (CVAAS) for the determination of Hg, and instrumental neutron activation analysis (INAA) for the determination of Se.

Abstract.A method for the determination of free iodide in human serum was developed. For this purpose iodide from pooled serum samples was separated from the organic manner by SEC. The iodide fraction subsequently was freezedried and analyzed by ion chromatography for quantification. Investigations for recovery and precision were carried out and were found to show sufficient results. For quality assurance ICP-MS was taken additionally as an total I-detector [1], using native and iodide-spiked serum samples. The iodide results of ICP-MS as well as those of IC were well corresponding. Iodine containing SEC-fractions from iodide-spiked samples showed no increased I-values except that in the iodide fractions, proving that there was no iodide conversion into other I-species (and vice versa) during the whole procedure.Free iodide from two serum pools of different healthy persons was determined as 2.25 and 2.43 gg I-/L, respectively. The values are related to total iodine levels determined by ICP-MS. For comparative reasons a table of individual iodine and iodide values is presented.Key words: iodide, iodine, ion chromatography, quality control, human serum.Iodine is an essential trace element [2, 31. I-containing hormones (thyroxine, tri-iodothyronine [4,5]) are strongly influencing an extended range of biochemical reactions. Usually different iodine species (e.g. IOn-, I-) are absorbed from the food and reduced to iodide (or remains iodide) in the gastro-intestinal tract [5]. The iodide pool in serum is considered as I-source for the complete synthesis of thyroxine and tri-iodothyronine. The sufficiency of I-supplementation can be seen directly by monitoring iodide in serum or secondarily by monitoring the urinary I--excretion [6]. The latter is state of the art because the direct iodide determination in serum was

The concentrations of the essential trace elements Cu, Fe, and Zn, and of the mineral elements Ca, K, Mg, and P during the perinatal period in human placenta and in the blood of the mother and the newborn (cord blood) were determined. Breast milk (colostrum and transitory milk) was also included to permit correlations between the different compartments. No correlations were found. The uptake by nutrition and the body-pools of the mother and their mobilization for these elements seem to be sufficiently high for an adequate supply of the fetus and the milk in the geographical region of Munich (Bavaria, FRG) under these investigations. Differences in the mineral-and trace element concentrations of colostrum and transitory milk for the elements P and Zn and to a lesser extent for Ca and Mg were observed. Additionally, breast milk samples from different geographical regions in Bavaria were investigated. Results for the heavy metals Cd, Hg, and Pb, and for the essential trace element Se are also presented for these samples, and can be seen as a reflection of the overall environmental and dietary influences during pregnancy in these geographical regions. ICP (Inductively Coupled Plasma)-emission spectrometry was used for the determination of the elements Cu, Fe, Zn, Ca, K, Mg, and P. For the additionally given elements in the milk-samples anodic stripping voltammetry (DPASV) (Cd, Pb), hydride atomic absorption spectrometry (AAS) (Se), and cold vapor AAS (Hg) were applied.