Nondestructive analysis of single crystals of selenide spinels by X-ray spectrometry techniques.

The paper presents possibilities and difficulties in nondestructive analysis of small multielement single crystals performed by means of X-ray spectrometry techniques: micro-X-ray fluorescence spectrometry (µ-XRF), energy-dispersive electron probe microanalysis (ED-EPMA), and X-ray photoelectron spectroscopy (XPS). The capability of the X-ray spectroscopy techniques in elemental analysis is demonstrated with the single crystals of selenide spinels of the general formula M(x)N(y)Cr(z)Se(4) (M(+2) and N(+3) are, for example, Zn(+2), V(+3), Ga(+3), Cd(+2), In(+3), and Sb(+3)). The results of the nondestructive analyses (µ-XRF, ED-EPMA, and XPS) are compared with those obtained by inductively coupled plasma optical emission spectrometry (ICP-OES) and wavelength-dispersive X-ray spectrometry (WDXRF) following sample digestion. The present study shows satisfactory agreement between the results of µ-XRF analysis performed using the standardless fundamental parameter method and the results obtained with the WDXRF and ICP-OES analyses. If the measured single crystal is precisely positioned, the difference between µ-XRF and wet analysis (WDXRF and ICP-OES) does not exceed 5% rel. The reliable results of ED-EPMA can be obtained only if the measured area is sufficiently large, i.e., of 200 × 300 µm. Even if this condition is fulfilled, the relative difference between the ED-EPMA and the wet analysis may reach 10% rel. In case of the XPS analysis, the accuracy of results depends on the proper preparation of the sample surface. It should be free of contamination that can be obtained by scraping in situ in ultrahigh vacuum. The ion etching, commonly used for cleaning the surface, leads to preferential sputtering; therefore, the reliable results cannot be obtained.

The use of human lymphoid cell line lymphokine preparations (LCL-LK) as working standards in the bioassay of human leucocyte migration inhibition factor (LIF).

The leucocyte migration inhibition test in agarose as described by Clausen (1971) was modified into a statistically designed assay of LIF activity using human polymorphonuclear leucocytes from single blood donors. Individual assays included a laboratory standard of lymphokine with LIF activity prepared from the culture supernatants of the RPMI 1788 human lymphoblastoid cell line (LCL-LK). Analysis of 157 LIF assays revealed simple criteria by which the acceptability of an individual assay could be judged before subjecting it to statistical analysis. The failure of LIF assays to meet these criteria of acceptability was particularly associated with low areas of control polymorph migration in the absence of lymphokine ('spontaneous migration'). We demonstrate that the statistically designed assay permits the measurement, with precision, of LIF activity in units/ml by reference to a working standard of LCL-LK. We illustrate the use of this assay in the measurement of LIF activity generated by tuberculin-stimulated human peripheral blood lymphocytes.

[Application of the chromatographic-spectrophotometric method for the analytical control of l-ascorbic acid in pharmaceutical and plant material]. / Zastosowanie metody chromatograficzno-spektrofotometrycznej do analitycznej kontroli kwasu L-askorbinowego w materiale farmaceutycznym i roslinnym.

The conditions of chromatographic separation allowing the isolation of L-ascorbic acid from its products of decomposition and other accompanying substances in the determined pharmaceutic preparation and plant materials were established. The isolated L-ascorbic acid was signed by the extractive--spectrophotometric method using coupled redox-complexation reactions with iron(III), 1, 10 phenantroline and bromophenol blue system. The analytical procedure allowing the evaluation of durability of vitamin C in multivitamin "Vitaral" preparate was described. The procedure was used also for the evaluation of the loss of L-ascorbic acid in the parsley and lovage in the process of drying and storage.

Effects of auxiliary liver transplantation on oxygen consumption in the graft and recipient's liver mitochondria. Possible inter-liver regulating mechanism.

Studies were made on inbred rats of Lewis strain with heterotopically transplanted syngeneic liver to assess the effect of this type of liver transplantation on the liver mitochondria. Mitochondria were isolated from own and transplanted liver in 1 and 3.5 months after auxiliary liver transplantation. They showed a progressive decrease in oxygen uptake and citrulline production accompanied by an increase in ATP-ase activity in mitochondria of the recipient's liver and of the graft, as well as diminution in their sensitivity to dinitrophenol, especially in the transplant mitochondria. The results suggest an existence of inhibitory factors transferred by the serum bringing the energetic function in recipient and auxiliary liver mitochondria to a similar level.