[Determination of erythrocyte zinc by atomic absorption spectrophotometry: Its significance in iron deficiency anemia (author's transl)]

Present investigation was undertaken to elucidate the significance of changes in erythrocyte zinc levels in anemia. A preliminary study for the determination of erythrocyte zinc by atomic absorption spectrophotometry was done. The simple dilution method, in which zinc was determined directly from a sample of erythrocyte lysed and diluted with deionized water, appeared satisfactory in view of its rapidity, simplicity and accuracy. Of importance is that the temperature of sample and standard solution had to be matched. By using the above method, the mode of changes in erythrocyte zinc levels was investigated in healthy individuals and it was found that erythrocyte zinc expressed per gram of hemoglobin was inversely correlated to mean corpuscular hemoglobin concentration (MCHC). This relationship was also shown in patients with iron deficiency anemia and phlebotomy-induced anemia in rabbits. However, erythrocyte zinc expressed per milliliter of packed red cells was generally increased in these cases. The difference of erythrocyte zinc levels between 9:00 a.m. and 3:00 p.m. was not statistically significant. In addition, the levels of the B and of the C type erythrocyte carbonic anhydrases were assayed immunochemically. It was ascertained that there was a significant correlation between erythrocyte zinc levels and those of total carbonic anhydrase. This, the clinical importance of changes in erythrocyte zinc levels in anemia was discussed in relation to the role of this zinc - metalloenzyme.

Determination of platinum, palladium, and lead in biological samples by atomic absorption spectrophotometry

A flameless atomic absorption method for the coextraction of platinum and palladium from biological and environmental samples by high molecular weight amine (HMWA) is given. Also, methods for lead determination in biological samples by use of extraction flameless analysis and direct aspiration-flame analysis are reported. A study of lead contamination of Vacutainer tubes is given.

Electrothermal atomic absorption spectrometry of trace metals in biological fluids

Electrothermal atomic absorption spectrometry has five major advantages for measurements of trace metals in biological materials, in comparison to measurements by conventional flame atomic absorption analysis: (1) Trace metal contamination is minimized by avoidance of preliminary chemical extractions and additions of reagents; (2) Sample volumes are small (1 to 50 mu1). The entire sample is vaporized in electrothermal atomization, whereas in most flame nebulization systems only a small fraction of the sample enters the flame; (3) Atoms are released in higher concentrations. In electrothermal atomization, the atom cloud is released into a relatively small volume of gas. In contrast, in flame atomization, the atom cloud is diluted by the high flow rate of gases and by expansion of gases during combustion; (4) Molecular recombination of atoms is retarded by the atmosphere of inert gas which restricts chemical reactions (e.g., oxidation). In contrast, in flame atomization, oxidation occurs very rapidly; and (5) By programmed increments in temperature, electrothermal atomization permits organic constituents to be pyrolyzed prior to vaporization and atomization of metals. Despite these advantages, electrothermal atomic absorption is particularly subject to interferences and sources of imprecision which necessitate critical evaluations in the prospective analyst's laboratory before an electrothermal method can be confidently employed for diagnostic measurements of a specific trace metal in body fluids.

Atomic absorption analysis of some trace metals of toxicological interest

A selective and critical review, mainly from 1971 to 1974, of atomic absorption applied to the determination of eight toxic metals (lead, mercury, cadmium, thallium, arsenic, bismuth, beryllium, and boron) in blood, urine, and tissue is presented. Discussion involves both flame and flameless atomization, sample preparation, matrix modification, background correction, and contamination. Advantages of other atomic spectrometric techniques and use of recent confirmatory instrumental methods are included. Some normal and toxic levels are mentioned.

Effect of carbon cup aging on plasma zinc determination by flameless atomic adosorption spectrometry

Determination of zinc in blood plasma by flameless atomic absorption spectrometry is discussed, with particular reference to the protocol required for the successful use of the Varian-Techtron Carbon Rod Atomizer. Cup aging is shown to be an important factor in limiting the precision of this analytical technique and ways of minimizing the problem are described. Matrix problems have also been encountered, which precluded the use of aqueous standard curves and the method of standard additions. We propose the use of plasma in preparing standard curves, the values for which are corrected for inherent plasma zinc, as a possible solution to the problem.

Ultramicroanalysis of metals by means of an integrating atomic absorption spectrometer and a carbon filament atom reservoir

A fast reacting atomic absorption spectrometer in combination with a carbon filament atom reservoir was used for ultramicroanalysis of calcium and magnesium. The analysis of 1 X 10(-12) mole of magnesium gave a variation of coefficient of +/-3% and analysis of 2 X 10(-11) mole of calcium gave one of +/-5%. The effect of adding various common biological substances to the samples in great excess was tested. No interference could be observed.

Use of teflon digestion bombs for tissue analysis: measurements of the effect of estradiol-17 beta upon hepatic copper in rats

Teflon digestion bombs have been used for pressure decomposition of rat liver samples preliminary to copper analyses by atomic absorption spectrometry. The analytical procedure is convenient and is consistently free from copper contamination. The recovery of copper added to liver samples (three mug Cu added per g wet wt) averaged 102 (S.D. plus or minus 3) percent. The accuracy of the copper analyses was verified by use of National Bureau of Standards reference bovine liver. The mean concentration of copper in perfused livers of 16 untreated male rats averaged 16.1 (S.D. plus or minus 2.3) mug per g dry wt. The mean concentration of copper in perfused livers of 8 male rats which received estradiol-17 beta in dosage of 50 mug per day, s.c., for 21 consecutive days was 21.7 (S.D. plus or minus 4.7) mug per g dry wt (p vs controls equals greater than 0.01). This study demonstrates that estrogen administration can cause a significant increase in the concentration of hepatic copper.

Analysis of mercurial preservatives in bacterins, vaccines, and antisera by atomic absorption spectrophotometry

A flameless atomic absorption method was developed for the determination of mercurial preservatives in biologicals. The assay was based on a quantitative determination of the mercury content of these preservatives. This method was used to analyze a variety of samples and yielded reproducible results with satisfactory recoveries. The procedure is presented in a simplified block diagram and described in detail relating its suitability for routine assay of large numbers of samples.