L. Papp

Effect of the different factors on the iontophoretic delivery of calcium ions from bentonite.

The calcium content of mud patches used for therapy is very small. Several mineral clays originating from Hungary served as a base material for experiments in order to find a suitable drug for transdermal introduction of calcium ions into the body. The Ca++ transport through the pig skin has been investigated in vitro in diffusion cells applying iontophoresis. Studies of electrical and physicochemical factors acting on the permeation kinetics of in vitro experiments were performed. The utilization of direct current has intensified the Ca++ transport through the pig skin (129.78+/-26. 15 microgram Ca/cm2). On using pulsate currents the amount of the Ca++ penetrating through the skin was 5-10 times higher (283.18+/-16.89 microgram Ca/cm2, 388.71+/-19.90 microgram Ca/cm2) than that of the passive transport (36.22+/-14.20 microgram Ca/cm2). The amount of Ca++ cumulated in the receptor compartment was directly proportional to the amount of bentonite (a natural mineral clay with a large cation exchange capacity) in the donor compartment and to the concentration of Ca++ in the lattice of the applied mineral clay. Therefore, the experiments were carried out on a bentonite previously enriched in Ca++ in its lattice (50 mg Ca/g bentonite). The results of the in vitro studies could open a new field of application in the therapy of osteoporosis or in the use of mineral substances.

In vivo iontophoretic delivery of calcium ions through guinea pig skin enhanced by direct and pulsating current

Studies were initiated to investigate the effect of the delivery mode of45Ca ions through guinea pig skin in vivo. Direct current (DC), pulsating current (PC) and a Bernard current form, the “courtes periodes” current profile (CP) were applied with the same current density (0.16 mA/cm2) and for the same duration (30 minutes). The45Ca ions were delivered from a Ca-bentonite patch radiolabeled with45Ca (a natural mineral clay rich in calcium, 50 mgCa/g). The total quantity of applied bentonite was 1.5g×10 days=15g.45Ca was counted in different biological samples of the animals. The delivery of45Ca ions into the body (systemic effect) is the highest when CP current is applied (6.87±0.95·10−12g/samples). The local effect appears to be more effective in case of DC current mode (5.89±0.12·10−12g/0.5g bone). Total calcium measurements proved that the result of transdermal radiocalcium delivery is not only an ion exchange process at the surface of the bone but a deposition of calcium ions into the hydroxiapatite matrix (the net calcium introduction, which represent the difference between the total calcium into the treated bone and total calcium into untreated bone varied from 15.52±2.42·10−3g/0.5g bone to 44.30±3.50·10−3g/0.5g bone). The results suggest that iontophoresis could be used to accumulate calcium into different target tissues using the appropriate current system.

Study of trace elements in patients on haemodialysis

The serum aluminium, zinc, copper, iron and cadmium levels were studied in patients on haemodialysis, by the atomic absorption method and spectrophotometry. The serum concentrations of zinc and copper were found to decrease with the frequency of dialysis treatments, while the serum levels of iron and aluminium increased. Referred to the time elapsed since the start of the dialysis programme, the serum concentrations of zinc decreased, while those of iron, copper and aluminium increased. Attention is drawn to published observations pointing to the hazard of aluminium intoxication and to the symptoms and consequences of copper and zinc deficiency.

Determination of Cr and Mn in aluminium wires and sheets by XRF, NAA and AAS

The fundamental parameters method (FPM) for X-ray fluorescence (XRF) has been applied to determine the MN, Cr and Sr components of aluminium wires and sheets. The results are compared with neutron activation analysis (NAA) and atomic absorption spectrometry (AAS). The FPM does not require standards, however, it requires the spectra of the pure element for the concentration determination.

Ein neuer Typ Graphitrohr-Strahlungsquelle für Atomemissionsuntersuchungen

Zusammenfassung Der Verfasser hat eine Graphitkuvette als elektrothermische Anregungstrahlungsquelle entwickelt, und sie an einen Emissionsspektrographen adaptiert. Damit bestand die Moglichkeit, aus 50–100 μl Losung simultan Multielement-Messungen durchzufuhren. Die Nachweisgrenzen von etwa 40 Elementen wurden festgestellt. Die Nachweisgrenzen sind im allgemeinen besser, als bei den flammentechnischen-Atomabsorptionsverfahren.

Accumulation of Hg(II) Ions in Mouse Adrenal Gland.

Female BALBc mice were administered HgCl2 at a single dose of 4 mg/kg i.p. The acute intoxication with Hg(II) salts (2 hr) caused accumulation of Hg(II) ions in the adrenal gland in general, and in the medulla, in particular. Based on data obtained with atomic absorption spectroscopy and quantitative cytochemistry, we determined the amount of mercury (II) in the adrenal glands and found it to be 14.2 ng Hg(II) (3.5 mg/kg wet weight of the adrenals). An uneven distribution of Hg(II) was found within the adrenal gland, not only between the medulla and cortex, but also within the cortex. The applied autometallographic method revealed that the cortex was negative except the zona glomerulosa, whereas the medulla showed a strong reaction localised to the chromaffin granules of the secretory cells. Both adrenaline and noradrenaline producing cells reacted. The comparison of the density of silver grains by scanning densitometry in the medulla and cortex revealed a significantly higher Hg(II) concentration in the medulla compared to the cortex (10 mg/kg vs 2 mg/kg, respectively). The results presented here suggest that there may be a connection between the symptoms of acute Hg(II) intoxication and its adrenal accumulation.

Development of hollow-cathode radiation sources. Part 1. Study of the effects of cones placed in the cavity on the emitted light intensity

Aluminium cones were placed in a hollow cathode in order to examine the plasma, and bore holes were made along the cavity wall, as described previously. On the basis of the light intensity emitted through the bore holes, the effect of cones of different lenght on the optimum excitation position was studied. Increased surface area of the cones gave higher emitted light intensities. Cones of different materials (Fe, Cu and Al) and of different lenghts (0–10 and 0–25 mm) were placed in cavities of different materials (length 10 or 25 mm) and for analytical purposes the emitted light intensity parallel to the cavity was examined for the cones of different length and with pairs of cones and cavities of different materials. The increase in the intensities of the lines emitted by the cones does not appear to be caused by an increase in surface area, but by the fact that the tip of the cone is placed in the optimum excitaion position. With short cavities the optimum excitation position changes with the ratio of the internal diameter of the cavity to the length. When carrying out multi-element analyses, a 3 : 1 ratio of length to diameter is recommended, as the optimum excitation positions for the elements studied (Fe, Cu and Al) are all at the same height in the cavity.

Emission Spectrometric Determination of the Main Components and the Trace Elements in Nonconducting Powders by Means of the Plastic-Bounded Electrode System

One of the methods most frequently used for the spectrochemical analysis of nonconducting powders is the excitation from the powder that has been loaded onto the electrode crater. The reproducibility in data obtained from this method can be increased if the nonconducting material is mixed with a conducting one and briquetted. The goal of this procedure is to obtain a more uniform material transport into the excitation source. Because of the disadvantages of the briquett method (i.e., the effect of the structure of the briquett, the dilution of the nonconducting material, and the great pressure that must be applied), the technique cannot be used for trace analysis purposes.

Über den bleigehalt in den ungarischen weinen

The authors have investigated the lead content of 560 hungarian wines produced between 1969 and 1973 by atomic absorption spectrophotometry (Type of instrument: UNICAM SP 1900). The preparation of samples was made by wet digestion with HNO3-H202. For 94.12% of the investigated wines less than 0.4 ppm lead content was established. The 2.67% of wines contain 0.4-0.6 ppm lead. In case of 18 samples (3.21%) more than 0.6 ppm lead content was found.SummaryThe authors have investigated the lead content of 560 hungarian wines produced between 1969 and 1973 by atomic absorption spectrophotometry (Type of instrument: UNICAM SP 1900). The preparation of samples was made by wet digestion with HNO3- H2O2. For 94.12% of the investigated wines less than 0.4 ppm lead content was established. The 2.67% of wines contain 0.4–0.6 ppm lead. In case of 18 samples (3.21 %) more than 0.6 ppm lead content was found.Zusammenfassung560 mit HNO3 veraschte ungarische Weine der Jahrgänge 1969–1973 wurden mit der Atomabsorptionsmethode auf ihren Pb-Gehalt untersucht. 94;1 % hatten einen Pb-Gehalt < 0,4 ppm, 2,7 % einen solchen von 0,4–0,6 ppm. Bei 18 Proben (3,2%) lag der Pb-Gehalt über 0,6 ppm.

Computer-controlled electrothermal–hollow cathode emission spectrometric source for the simultaneous multi-element determination of trace elements in environmental liquid samples in microlitre amounts

A combined electrothermal–hollow cathode emission spectrometric source is described, which is capable of simultaneous multi-element analysis with absolute detection limits lying in the range 10–11–10–12 g (determined for a volume of 10 µl). Details of the electrothermal heating, discharge control and detection power are given, and results of the analysis of water samples are presented.