Comparison of the Content of Several Elements in Seawater, Sea Cucumber Eupentacta fraudatrix and Its High-Molecular-Mass Multiprotein Complex.

Metal ions and other elements play many different critical roles in all biological processes. They can be especially important in high concentrations for the functioning of organisms living in seawater. It is important to understand how much the concentrations of different trace elements in such organisms can be higher than in seawater. Some marine organisms capable of rapid recovery after different injuries are fascinating in this regard. Sea cucumbers Eupentacta fraudatrix can completely restore all organs and the whole body within several weeks after their division into two parts. Here, for the first time, a comparison of the content of different elements in seawater, sea cucumber, and its very stable multiprotein complex (2000 kDa) was performed using two-jet plasma atomic emission spectrometry. Among the 18 elements we found in sea cucumbers, seawater contained only six elements in detectable amounts, and their content decreased in the following order: Mg > Ca > B > Sr ≈ Si > Cr (0.13−930 µg/g of seawater). The content of these elements in sea cucumbers was higher compared with seawater (-fold): Ca (714) > Sr (459) > Cr (75) > Si (42)> B (12) > Mg (6.9). Only four of them had a higher concentration in the protein complex than in seawater (-fold): Si (120.0) > Cr (31.5) > Ca (9.1) > Sr (8.8). The contents of Mg and B were lower in the protein complex than in seawater. The content of elements additionally found in sea cucumbers decreased in the order (µg/g of powder) of P (1100) > Fe (47) > Mn (26) > Ba (15) > Zn (13) > Al (9.3) > Mo (2.8) > Cu (1.4) > Cd (0.3), and in the protein complex, in the order of P (290) > Zn (51) > Fe (23) > Al (14) ≈ Ni (13) > Cu (7.5) > Ba (2.5) ≈ Co (2.0) ≈ Mn (1.6) > Cd (0.7) >Ag (0.2). Thus, sea cucumbers accumulate various elements, including those contained in very low concentrations in seawater. The possible biological roles of these elements are discussed here.

Twenty Element Concentrations in Human Organs Determined by Two-Jet Plasma Atomic Emission Spectrometry.

In this paper, we have performed determination of the concentration of twenty elements in seven human organs (spleen, liver, kidney, muscle, heart, lungs, and brain) using two-jet plasma atomic emission spectrometry. The method allows multielemental analysis of solid samples without wet acid digestion. Before analysis, all human organs were first dried, ground to powders, and carbonized. The relative content of elements in each of the seven organs was very different depending on the donor. The average content of twenty elements in various organs varied in the following ranges (µg/g of dry weight): Ag (<0.02-0.2), Al (2.1-263), B (<0.5-2.5), Ca (323-1650), Cd (<0.1-114), Co (<0.2-1.0), Cr (<0.5-4.0), Cu (4.2-47), Fe (156-2900), Mg (603-1305), Mn (0.47-8.5), Mo (<0.2-4.9), Ni (<0.3-3.1), Pb (<0.3-1.9), Si (31.6-2390), Sn (<0.3-3.2), Sr (0.2-1.0), Ti (<2-31, mainly in lungs), and Zn (120-292). The concentration range of Ba in organs of five donors was <0.2-6.9 and 2.0-5600 for one donor with pneumoconiosis (baritosis). The maximum element contents were found, respectively, in the following organs: Al, B, Cr, Ni, Si, Sn, Sr, Ti (lungs), Fe (lungs and spleen), Mn (liver and kidney), Ag and Mo (liver), Ca (lungs and kidney), Cu (brain), Cd (kidney), Pb (brain), and Zn (liver, kidney, and muscle). The minimal content of elements was observed, respectively, in the following organs: Ag (all organs except liver), Ba (spleen, muscles, and brain), Ca and Mg (liver), Si (liver, muscle, and brain), Cd and Sr (heart and brain), Al, Cu, Fe, and Mn (muscle), and Zn (spleen and brain). The analysis of possible biological role and reasons for the increased content of some elements in the organs analyzed was carried out.

Comparison of Trace Elements in High-Molecular-Mass Multiprotein Complex and in Female Milk from Which It Was Obtained.

BACKGROUND: Many biological processes are performed by different protein complexes. During the association of proteins and enzymes forming specific complexes, the latter can include ions of various metal ions, which may be important for their formation and biological function. OBJECTIVE OF THE STUDIES: However, to date in the literature there are no data on metal ions that are part of any protein complexes. METHODS: A very stable multiprotein complex (~1000±100 kDa) was separated from other proteins of nine samples of female milk by gel filtration on Sepharose 4B. The content of microelements in the stable multiprotein complex and milk was analyzed using two-jet plasma atomic emission spectrometry. RESULTS: The content of different elements in milk on average decreased in the order: Ca>P>Mg>Al≥Zn≥Fe>Cu >B (0.76-3500 µg/g of dry milk powder), while the content of some elements was very low (Sr>Mn>Cr>Ba>Pb>Ag>Ni>Cd, <0.03-0.5 µg/g). The content of eight elements in stable multiprotein complex was 1.2-9.6-fold higher than in milk and increased in the order: Ca≈MgB (19.7)>Ag (28.7)>Ni (38)≥Sr (110). CONCLUSIONS: The analysis of the relative content of sixteen elements in human milk and oligomeric complexes of proteins was performed for the first time. Data on the content of metals indicate that during the formation of protein which associates the increase in the content of metal ions bound with proteins of the complex can occur. Such metal ions can be important for the formation and biological function of protein complexes.

Solid Sampling in Analysis of Various Plants Using Two-Jet Plasma Atomic Emission Spectrometry.

The possibility of two-jet plasma atomic emission spectrometry for analysis of different plants using solid sample preparation and unified calibration samples was investigated. The certified reference materials of wheat, maize, rice, potato, grass mix, birch leaves, and Elodea canadensis were used for analysis. On the basis of the behavior of these plants in the plasma, they were divided into two groups: starch-containing materials (cereal and root crops) and leaves/grass. It was found that the previous sample carbonization should be used for analysis of starch-containing plants while leaves and grass could be analyzed by the direct technique. Carbonization was only applied for determining low concentrations of trace elements in leaves and grass. The calibration samples based on graphite powder and simple sample preparation, dilution of powdered sample with a spectroscopic buffer, were used for both direct analysis and analysis after carbonization. Such an approach allowed estimation of B, Ba, Be, Cd, Co, Cr, Cu, Ga, Fe, Mn, Ni, Pb, Si, Sr, V, and Zn in different plants. The limits of detection (LODs) provided by the direct technique were at the level of (µg·g-1): n × 0.1 for Cd, Cu, and Mn; n for B, Ba, Co, Cr, Fe, Ga, Ni, Pb, Sr, V, and Zn; n × 10 for Si. Carbonization allowed improving LODs of elements several times depending on the thermal stability and mineral composition of plants. The LODs of elements in plants obtained after carbonization are the following (µg·g-1): n × 0.01 for Be, Cd, Cu, and Mn; n × 0.1 for Co, Cr, Fe, Ga, Ni, Pb, Sr, V, Zn; and n for Si. The techniques suggested are fast, easily workable, and do not require harmful chemical reagents. In some cases, the influence of variable matrices and different element species on analytical signal of elements was not completely suppressed; the deviation of element concentrations from the true values was discussed.

Solid Sampling in Analysis of Soils by Two-jet Plasma Atomic Emission Spectrometry.

The possibility of direct analysis of soils by two-jet plasma atomic emission spectrometry was investigated using certified reference materials of black earth, grey desert and red soils. It was shown that As, B, Cd, Cu, Hg, P, and V could be determined after a 2-fold, and Be, Co, Cr, Ga, Nb, Pb, and Zn-after a 10-fold dilution of the samples by a spectroscopic buffer using calibration samples based on graphite powder. The strongest matrix effects were revealed for red soil having the highest Al and Fe concentration, which led to the overstated concentrations of some elements. The overstating factor depended on analyte concentration and was no more than 2. A clear advantage of the suggested technique over existing methods is the simple sample preparation process, which requires no reagents except a spectroscopic buffer, and possibility of using the same calibration samples for analysis of different soils.

Simultaneous determination of Fe, P, Ca, Mg, Zn, and Cu in whole blood by two-jet plasma atomic emission spectrometry.

Availability of many biological samples in ample quantity for biomedical investigations sometimes is very restricted. Therefore, there is the need for the simple techniques allowing the analysis of small amount samples. In the present work the two-jet plasma atomic emission spectrometry techniques for the determination of Fe, P, Ca, Mg, Zn, and Cu in whole blood are proposed. The first technique is developed for direct analysis of freeze-dried blood. The sample preparation consisted in a dilution of blood powder (particle size 20 microm or less) with a spectroscopic buffer (graphite powder containing 15 wt.% NaCl). For the analysis of liquid whole blood, previous carbonization (not ashing) of blood evaporated on graphite powder was applied. Calibration samples based on graphite powder containing 15 wt.% NaCl were used. The validation of the techniques was confirmed by the use of different sample preparation procedures (wet acid digestion and dry carbonization), the analysis of IAEA A-13 reference material (freeze-dried bovine whole blood), and the comparison of the results obtained by the proposed technique with the results of the stripping voltammetry technique. Just 20-50 microL of whole blood is quite enough for all determinations. The proposed techniques were successfully applied for the simultaneous determination of Fe, P, Ca, Mg, Zn, and Cu in whole blood of living experimental rats and mice and human blood.

Determination of trace elements in bone by two-jet plasma atomic emission spectrometry.

This paper describes an analytical method for trace element determination in bone tissues. The study of the influence of the bone matrix showed that the addition of 25% ground bone to graphite powder with introduced impurities did not affect the analytical signal of elements in the spectral excitation in a two-jet plasma. On basis of these investigations a method for direct multielement analysis of bone tissues was suggested. The sample preparation procedure consisted in mixing powdered bone (particle size 30 µm or less) with a spectroscopic buffer (graphite powder plus NaCl) in ratio 1:3 or to a greater extent depending on the analyte concentration. Reference samples based on graphite powder were used for construction of calibration curves. The NaCl concentration in analyzed and calibration samples was 15 wt%. The effect of particle size was revealed from the determination of Ba, Sr, and Mg. To eliminate this effect, treatment of the samples with nitric acid was proposed. The validation of the technique was confirmed by comparison of the analysis results of a bone sample with those obtained by inductively coupled plasma atomic emission spectrometry after wet acid digestion. The limits of detection estimated for 20 elements were the following (µg g(-1)): 0.1 (Ag), 1.0 (Al), 1.0 (Ba), 0.1 (Be), 1.2 (Bi), 0.4 (Cd), 1.0 (Co), 0.2 (Cu), 0.6 (Cr), 1.9 (In), 2 (Fe), 0.3 (Ga), 0.4 (Mn), 0.4 (Mo), 0.7 (Ni), 1.0 (Pb), 0.7 (Sn), 0.8 (Tl), 5 (Sr), 1.0 (Zn).