Zinc and copper determination in microsamples of serum by flow injection and atomic absorption spectroscopy

Serum concentration of zinc, copper, iron, and its associated factors among pregnant women of small-scale farming in western Ethiopia

Micro-nutrients are required in small amounts to maintain growth and cell functioning to complete the life cycle through reproductions. However, pregnant women in developing countries like Ethiopia are vulnerable to multiple micro-nutrient deficiencies. Therefore, this study aimed at assessing the serum level of metals and associated factors like dietary diversity, and health-related problems in pregnant women among small-scale farming in Kellem Wellega, western Ethiopia. A cross-sectional laboratory-based study was conducted from June to August 2021 on 417 pregnant women attending antenatal care at rural healthcare facilities. Data was collected by using per-tested structured questionnaires via face-to-face interviews. The data analysis was conducted using SPSS version 24.0, and multivariate logistic regression analysis was performed to determine the association between predictor and outcome variables. A statistically significant was considered at p value < 0.05 for all the analyses. Our study findings showed that 62.1, 80.9, and 71.9% of the participants were deficient in iron, zinc, and copper micro-nutrient levels, respectively. Pregnant women who could not have formal education were 3.24 (AOR = 3.24, 95% CI 1.33-7.91) and 3.98 (AOR = 3.98, 95% CI 1.2-13.15) times more likely to show zinc and copper deficiency than those who attended secondary school and above, respectively. Furthermore, pregnant women involved only in farming activities were 0.57 (AOR = 0.57, 95% CI 0.36-0.91) and 4.33 (AOR = 5.72, 95% CI 2.34-13.97) times more likely to be exposed to iron and zinc deficiency than those who were engaged in other activities. This study revealed that pregnant women with low income were 6.36 times more likely to be exposed to zinc micro-nutrient deficiencies than those with high-income participants (AOR = 6.36, 95% CI 1.47-27.61). Additionally, those participants who ate a varied diet between 1 and 4 items per day were 2.26 (AOR = 2.26, 95% CI 1.43-3.59) and 2.77 (AOR = 2.77, 95% CI 1.6-4.61) times more likely to suffer zinc and copper micro-nutrient insufficiency than those who consumed 5-10 items per day. Finally, pregnant women who developed diarrhea in the past three months were 1.82 (AOR = 2.77, 95% CI 1.14-2.92) and 2.52 (AOR = 2.52, 95% CI 1.3-4.91) times more likely to be exposed to iron and copper deficiency than those who never show the symptoms, respectively. This study identified low concentrations of zinc, iron, and copper in the blood serum of pregnant women of small-scale farmers.

Serum trace elements and fat-soluble vitamins A and E in healthy pre-school children from a Venezuelan rural community

Zn (SZn), Cu (SCu), Fe (SFe), vitamin A (SVA) and vitamin E (SVE) were measured in blood serum samples of 85 healthy pre-school children aged 2-6 yr. from the rural community of Canaguá, Mérida State, Venezuela. The relationship between these biochemical indexes was also investigated. The mean serum concentrations of zinc, copper, iron, vitamin A and vitamin E were 0.74 +/- 0.25, 1.18 +/- 0.30, 0.76 +/- 0.20, 0.30 +/- 0.15 and 5.87 +/- 0.43 mg/L, respectively. There was a tendency for SZn to increase with age, whereas SCu and SVA decreased. There was no significant difference in serum trace elements and fat-soluble vitamin concentration between males and females in the different age groups. SFe tended to be lower than that reported in the literature. However, the age groups studied showed no statistically significant sex- and age-related differences. The present study shows that there is a complex interaction between SZn, SCu, SFe, SVA, SVE and age of the children. Multiple regression analysis showed serum zinc was strongly related to serum copper, and serum iron. Serum vitamin A was strongly related to serum zinc and serum vitamin E, whereas serum vitamin E was strongly related to serum zinc, serum copper, and serum vitamin A. On the other hand, our observations also suggest that more detailed studies of these metals and fat-soluble vitamins should be carried out, and that the study should include nutritional surveys, metabolic balances and associations between SZn, SCu, SFe, SVA and SVE and anthropometric variables (height, weight, body mass index and skinfold thickness).

Application of covalent affinity chromatography with thiol-disulphide interchange for determination of environmental exposition to heavy metals based on the quantitative determination of Zn-thionein from physiological human fluids by indirect method based on analysis of metal contents

Intoxication with heavy metals results in numerous poisonings and diseases. They disturb metabolism of the system, are the source of cancer, degeneration changes and others. As a result of kidney damage the urine of people exposed to heavy metals contains different low molecular weight proteins, oligopeptides and amino acids, indicating pathological changes. One of the proteins is a very specific metallopolythiopolypeptide--metallothionein (MT). Based on earlier investigations, a very good correlations has been found between the contents of metallothionein in urine and plasma and the concentration of heavy metals in the blood, urine, kidneys, liver and brain and general in level of exposition to heavy metals. The aim of our investigations was to carry out quantitative isolation of Zn-thionein (Zn-Th), in order to determine the level of exposition to heavy metals. For Zn-Th protein isolation by covalent affinity chromatography with thiol-disulphide interchange (CAC-TDI) was applied, which is a modern technique of separation of a high affinity, good repeatability and reproducibility, allowing specific isolation of the thiol-proteins CAC-TDI gel was used as a solid-phase extraction (SPE) support for preconcentration of Zn-Th protein and Zn bonded with Zn-Th from water, rine, plasma and breast milk samples. The investigations showed unfavourable effect of the support on separation of thiol proteins and good correlation between the concentration of MTs protein added to water, plasma and urine and the concentration of protein indirectly determined via atomic absorption spectrometric (AAS) method, by preconcentration on SPE support metals formerly bound with MT protein and absorbed on CAC-TDI gel and calculated from metals concentration. The present paper is a continuation of earlier experiments on quantitation of Hg-thionein and Cd-thionein in physiological fluids and homogenates.

Altered 5-aminolevulinic acid metabolism leading to pseudoporphyria in hemodialysed patients

Hemodialysed patients with no history of porphyria may present neurological symptoms similar to those seen in acute porphyrias. Porphyria has been associated with an increase in plasma levels of 5-aminolevulinic acid and porphobilinogen. Our aim was to evaluate these parameters and the activities of the enzymes involved in the first steps of heme metabolism in non-porphyric hemodialysed patients. The activities of 5-aminolevulinate dehydratase and deaminase were determined in red blood cells (RBC) from 78 hemodialysed patients, before and after dialysis. Plasma levels of 5-aminolevulinic acid, porphobilinogen and zinc were also measured. These parameters were also measured in 40 volunteers to obtain controls levels. The levels of 5-aminolevulinic acid (0.98 +/- 0.09 microgram/ml) and porphobilinogen (1.32 +/- 0.13 micrograms/ml) were raised in non-porphyric patients prior to hemodialysis (P < 0.001) compared with controls (5-aminolevulinic acid 0.13 +/- 0.02 microgram/ml; porphobilinogen 0.90 +/- 0.09 microgram/ml). After dialysis there was a decrease in both 5-aminolevulinic acid (to 0.61 +/- 0.05 microgram/ml) and porphobilinogen (to 1.10 +/- 0.16 micrograms/ml) although both parameters remained higher than controls (P < 0.001). The activities of both 5-aminolevulinate dehydratase (0.550 +/- 0.095 U/ml RBC), and deaminase (54.13 +/- 9.13 U/ml RBC) were diminished in blood samples of patients before dialysis (P < 0.001) compared to controls (dehydratase 0.975 +/- 0.115 U/ml RBC; deaminase 77.32 +/- 10.00 U/ml RBC). After dialysis 5-aminolevulinate dehydratase activity was partially recovered (to 0.666 +/- 0.100 U/ml RBC) while deaminase returned to normal values (73.45 +/- 9.46 U/ml RBC). The plasma zinc concentration in hemodialysed patients (44 +/- 12 micrograms/100 ml) was significantly lower than controls (105 +/- 30 micrograms/100 ml, P < 0.001). Addition of 22.5 mM zinc to the dehydratase reaction mixture raised the activity of 5-aminolevulinate dehydratase in blood samples of hemodialysed patients taken before and after dialysis. The study reports a partial loss of activity of 5-aminolevulinate dehydratase and deaminase activities in red blood cells from non-porphyric patients undergoing hemodialysis. Since plasma zinc levels were below normal in hemodialysed patients, and the activity of 5-aminolevulinate dehydratase could be restored by the addition of zinc, it is suggested that these abnormalities in heme metabolism may be explained by altered zinc and associated antioxidant status following dialysis.

Changes in the total content of iron, copper, and zinc in serum, heart, liver, spleen, and skeletal muscle tissues of rats infected with Trypanosoma cruzi

The effects of the Trypanosoma cruzi infection on the total content of the essential trace elements iron (Fe), copper (Cu), and zinc (Zn) in serum, heart, liver, spleen, and skeletal muscle were determined in "Wistar" rats inoculated with reticulotropic "Y" strain trypanosomes (Tryps) in their slender blood form. The 250 rats were divided in two groups of 80 rats (L-1 and L-2) and one of 90 (C) used as controls. L-1 and L-2 were inoculated with 2 x 10(5) and 5 x 10(2) Tryps, respectively. Ten rats of the C group were killed the inoculation day (i), and ten rats of each group chosen at random were killed and blood parasitemia determined at 5, 10, 15, 20, 25, 30, 60, and 90 post-i days covering the infection acute-phase myocarditis. Previously cryohomogenized and lyophilized tissues were digested in an HNO3- H2O2 mixture with the aid of a microwave oven, and the elements Fe, Cu, and Zn were determined by Flame Atomic Absorption Spectrometry. Generally, more intense changes were observed in the L-1 group. Serum Fe and Zn levels are lower and Cu levels higher in groups L-1 and L-2 than in C. However, Fe is not significantly sequestered in the liver during the acute phase of the infection as expected, but of the tissues studied, the spleen was the main site of Fe binding. Zn tended to increase in all tissues, except in the spleen, where during the acute phase of the infection, the total content of Zn in groups L-1 and L-2 was lower than in group C. Cu increased mainly in the spleen and muscle. In general, each tissue presented its own pattern of redistribution related to its nature, functions, and number of parasites inoculated, and these patterns may have been altered by the tropism of the parasite.

Oral zinc therapy normalizes serum uric acid level in Wilson's disease patients

The authors investigated changes in the serum uric acid (s-UrA) level seen in a Wilson's disease patient who had to undergo oral zinc therapy because of the occurrence of D-penicillamine-induced acute sensitivity reactions, including neutrophilic agranulocytosis, thrombocytopenia, and skin eruptions. Although s-UrA levels were low before oral zinc therapy (mean +/- SD, 1.60 +/- 0.20), they increased (mean +/- SD, 2.63 +/- 0.32) to within normal range (2.8-8.0 mg/dl) after therapy. There were no significant changes in the renal tubular reabsorption of UrA during oral zinc therapy. This therapy also produced an improvement of the decreased cholinesterase (ChE) values usually seen in Wilson's disease. These results suggest that oral zinc therapy can normalize UrA metabolism in Wilson's disease by improving liver dysfunction and increasing UrA synthesis.

Direct determination of calcium and magnesium in serum using flow-injection analysis and atomic absorption spectroscopy

The use of flow-injection analysis for the direct determination of calcium and magnesium in blood serum and plasma is described. An inexpensive rotary valve is used to inject the serum sample (4 microliters) into a flowing non-segmented stream of reagent which carries the sample slug through a long narrow-bore coil--where it gradually disperses--and into the nebuliser of an atomic absorption spectrometer. This on-stream sample dilution removes the need for predilution of the sample. The resulting absorbance signals are recorded as peaks less than 40 seconds after sample injection. Analytical recoveries and precision are good for both elements and the results by flow-injection analysis compare well with established routine methods.

Serum iron and total iron-binding capacity determination by flow-injection analysis with atomic absorption detection

The deproteinised sample (150 microliters) is 'injected' into a continuously flowing stream of deionised water which is pumped, via a capillary tube, to the nebuliser of an atomic absorption spectrophotometer. Analytical readout is obtained, in the form of transient peaks, 6 s after sample injection. Before injection traces of haemoglobin are removed from the serum by treatment with trichloroacetic acid-ascorbate solution. This protein precipitant facilitates rapid removal of haemoglobin bound iron without the need for heating. After centrifugation the supernatant solution is introduced into the flowing stream by use of a novel inexpensive 'injector'. Analytical recovery and precision are good, and results compare well with those obtained by a standard AutoAnalyzer procedure.