23 research outputs found
Non-Destructive Neutron Activation Analysis of Copper in Liver Samples and other Biological Materials
Peer Reviewe
Quantification of the metal distribution in metallothioneins of the human liver by HPLC coupled with ICP AES
Fractions containing metallothioneins MT , extracted from the liver cytosol of humans, were analysed to determine the complete distribution pattern of the metals copper, cadmium and zinc. Samples of cirrhotic livers which had come from organs removed during transplantation, were examined for differences in the trace element binding pattern. After the extraction of supernatants from the tissue samples, membrane ultrafiltration of the cytosolic solution was carried out to separate all high molecular proteins with molecular weights gt;100 kDa. This procedure retains the metal content of the MT s in its initial form, in contrast with the often used heat treatment of samples, which changes the copper distribution significantly. The MTs themself were isolated using size exclusion and anion exchange chromatography. Their metal content was determined simultaneously on line by combination with an ICP AES as element detector. Calibration of the procedure was by means of a column by pass injection of elemental standards into the separation system. The MT content in the samples was calculated using the determined metal concentrations and the generally accepted metal protein ratios for Cu 12 1 , Cd 7 1 and Zn 7 1 . These values were compared with values resulting from a 109Cd saturation assay. When various liver samples of different pathogenesis were compared, the highest level of Cu MT was found in primary biliary cirrhosis
Determination of aluminium in infusion solutions by inductively coupled plasma atomic emission spectrometry a critical comparison of different emission lines
Seven emission lines for the determination of Al in infusion solutions by means of inductively coupled plasma atomic emission spectrometry were compared. For this comparison, wavelength scans of different samples were made in order to study the background in the region of each line and to inspect for interference structures arising from molecular bands of water and argon. Background equivalent concentrations and detection limits were calculated for the emission lines at 167, 237, 394 and 396 nm. The detection limits were 1.2 amp; 956;g l 1 for the 167 nm line, 8.8 amp; 956;g l 1 for the 237 nm line, 10 amp; 956;g l 1 for the 394 nm line, 4.7 amp; 956;g l 1 for the 396 nm line and gt; 10 amp; 956;g l 1 for the other three lines 226, 308 and 309 nm . The Al content of various infusion solutions was determined on different days using the three emission lines with the lowest detection limits 167, 237 and 396 nm . Day to day variation was approximately 5 in all cases. As a final step, the Al contamination of 25 infusion solutions for parenteral nutrition was evaluated by using the two most suitable emission lines 167 and 396 nm . No statistically significant differences between the results were detected. Advantages and disadvantages of these two emission lines for the determination of Al are discusse