Quantitative Determination Of Zinc Research Articles

THE LEVEL OF ZINC IN BLOOD PLASMA AND THE COURSE OF GALLSTONE DISEASE IN CHILDREN

Determining the zinc level in children's blood plasma is an urgent problem, given its possible participation in the formation of cholelithiasis.Aim. To investigate the level of zinc in the blood plasma and the clinical course of gallstone disease (GSD) in children.Methods. 69 children aged 10-17 years and 25 children without biliary tract pathology were selected by the method of simple randomization. Verification of the diagnosis was carried out by applying dynamic ultrasound examination and X-ray examination of the organs of the abdominal cavity. Quantitative determination of zinc in blood plasma was carried out using mass spectrometry.Results. Dysfunction of the biliary tract according to the hyperkinetic type occurred in 55.1±7.1% of children and according to the hypokinetic type in 44.9±3.9%. The asymptomatic variant of housing and communal services was observed in 23.9%, painful - in 54.3% of patients, paroxysmal - in 21.7% of patients. The plasma concentration of zinc in children with gastrointestinal diseases was 1.87 times lower than in children of the comparison group and 1.37 times lower than in children with hyperkinetic gallbladder dysfunction, while there was a probable difference between these indicators in children with housing and communal services and in children with the hypotonic type of gallbladder dysfunction (p<0.05).Conclusions. 1. The leading syndromes of gallstone disease in children were pain and dyspepsia. 2. Gallstone disease in children occurs against the background of gallbladder dysfunction with a predominance of the painful course, the formation of solitary bilirubin-derived concretions and minor changes in biochemical blood analysis. 3. The concentration of zinc in the blood plasma of children with gallstone disease is probably lower than in children of the comparison group and does not depend on age and gender.

Determination of Zn2+ in Solid Pharmaceutical Dosage Forms by Means of Spectrophotometry in Micellar Media: Method Validation

In this study, a spectrophotometric method for the quantitative determination of zinc in a dietary supplement was validated. Zinc forms a ternary complex with Xylenol Orange and cetylpyridinium chloride in acetate buffer at pH = 5.5. The complex exhibits an absorption maximum at 560 nm. Linearity (range was 0.5–1.5 µg/mL, and correlation coefficient of the calibration curve was 0.9998), precision (repeatability variation coefficient and reproducibility variation coefficient were 1.57% and 1.77%, respectively), and accuracy (confidence interval of the mean recovery was 98.29–100.55%) of this method fulfil current pharmacopeial requests. Results obtained by spectrophotometric method were statistically compared with ones obtained by atomic absorption spectrometry and good agreement was found. The method can be applied routinely for quality control of solid pharmaceutical dosage forms containing zinc.

On the characterisation of carbon black from tire pyrolysis

A commercially available pyrolytic carbon black (CBp) produced from the pyrolysis of used tires was analysed by TGA-DTA showing that the effective carbon black content about 70% by weight, while about 14% are ashes and about 16% rubber pyrolysis residues adsorbed on the surface. GC-MS analysis of the latter fraction has permitted to identify at least 34 different molecules, some of them under the form of alkylated benzenes and alkylated naphthalenes and higher PAHs. Two simple procedures are shown to be effective in the quantitative determination of zinc and sulphur content of CBp. The surface area of CBp should be evaluated with both the ASTM D6559-19 and the ASTM D4607 test methods. CBp was also analysed with SEM-EDX and with FT-IR and Raman Spectroscopy. The latter spectroscopical technique was employed both on pristine and thermally annealed CBp, demonstrating that also CBp is a partially graphitizable carbon black similar to the N774 ASTM grade.

Содержание цинка и меди в почве и растении в разные периоды вегетации

Important biogenic elements of plants are zinc and copper, which come into them from the soil in the form of cations. Plants selectively absorb the elements they need in accordance with physiological and biochemical needs, as well as the characteristics of their vegetation. Copper and zinc are part of the enzymes that are necessary for the normal course of many biochemical reactions. Lack or excess of any chemical element causes a violation of the normal course of biochemical and physiological processes in plants. The paper presents the results of the study of zinc and copper content in the soil, as well as in the above-ground and underground organs of the studied plant object. Quantitative determination of zinc and copper was carried out on an atomic absorption spectrometer. As an object of study, a flower plant of the Gentian family (lat. Gentianáceae), genus Eustoma (lat. Eustoma), grade Aube Pink Picotee. Vegetation experiments were carried out on the basis of LLC "Greenhouse "Iceberg". According to the data, the content of zinc and copper in the organs of the studied plant decreases in a number of root – aboveground part – flower. In different periods of vegetation there is a different accumulation of copper and zinc in the aboveground and underground organs. The root of this plant performs a barrier function, blocking the flow of copper into the plant from the soil at 27 weeks of development. In this case, the zinc content in the root of the plant during this period increases significantly, but this figure in the above-ground part of the plant varies slightly. According to the calculated average value of the biological absorption coefficient, it can be seen that the accumulation of zinc in the plant occurs to a greater extent than the accumulation of copper.

Quantitative determination of zinc in milkvetch by anodic stripping voltammetry with bismuth film electrodes

Bismuth film electrode (BiFE) was shown to be an attractive alternative to common mercury film electrode (MFE) for anodic stripping voltammetric measurements. In this study, bismuth film, that was in situ deposited onto glassy carbon electrode, was used to detect zinc content of milkvetch, used in traditional Chinese medicine. Variables affecting the response have been evaluated and optimized. Experimental results showed a high response, with a good linearity (between 0.5 × 10 −6 mol L −1 and 3 × 10 −6 mol L −1) a good precision (R.S.D. = 3.58%) and a low detection limit (9.6 × 10 −9 mol L −1 with a 120 s anodic). The anodic stripping performance makes the bismuth film electrode very desirable for measurements of trace nutritive element zinc in milkvetch and should impart possible restrictions on the use of mercury electrode.

Quantitative determination of zinc, iron, calcium, and phosphorus in the total diet market basket by atomic absorption and colorimetric spectrophotometry.

Quantitative determination of zinc, iron, calcium, and phosphorus in the total diet market basket by atomic absorption and colorimetric spectrophotometry.

Radioisotope-induced X-ray fluorescence in the analysis of atmospheric particulates: Quantitative determination of zinc and lead

Multielemental analysis of atmospheric particulates collected on filter paper has been investigated using different radioisotopic exciting sources. Quantitative determinations for zinc and lead during a one year period are reported.

New Collaborative Study of a Zincon Ion Exchange Method for the Quantitative Determination of Zinc in Fertilizer

Abstract A collaborative study was performed with 8 Magruder samples to evaluate a new zincon colorimetric method, an alternative to 2.137. The previous zincon method was modified, but the basic principle remains: 0.5N HCl retains a stable Zn(II) chloro-complex ion on an anion exchange resin but not interfering cations; 0.005N HCl elutes the Zn(II) ion which is determined colorimetrically in the presence of the indicator, zincon. Overall estimate of precision, Sr = 0.033, is similar to Sr = 0.030 for atomic absorption. Sb values (0.074 at 0.05%, 0.035 at 0.25%, and 0.054 at 1%) compare favorably with atomic absorption Sb values (0.072 at 0.05%, 0.036 at 0.25%, and 0.063 at 1%). F- and t-test results at the 95% confidence level indicate systematic error by both methods but do not discern a difference in the true value each method can measure. Average single sample values agree better with Magruder grand averages than corresponding averages by atomic absorption. While applicable to samples containing 0.05% zinc and higher, the method is quite time consuming when samples are low in zinc and have high iron—zinc ratios. This method has been adopted as official first action.

Collaborative Study of a Zincon Ion Exchange Method for the Quantitative Determination of Zinc in Fertilizers

Abstract This collaborative study represents an attempt to validate the ion exchange zincon method for the quantitative determination of zinc in fertilizers. The values of the standard deviations Sd, Sr, and Sb and the results of the F- and t-tests are presented as an estimate of the precision, accuracy, and dependability. Atomic absorption measurements were also made and provided reference data for evaluation purposes. In its present form, the method falls short of expectations as an alternative wet approach to the dithizone method. It is recommended that the methods for determining zinc in fertilizers be studied further.

Determination of metal ions in solution by means of taa and edtaGeneral introduction and determination of zinc

Summary The behaviour of metal ions with EDTA and TAA in acid and alkaline solutions is discussed and a specific quantitative determination of zinc is described. The use of TAA instead of hydrogen sulfide provides a much better separation of zinc from the elements of group II. After addition of EDTA and ammonia, iron, aluminium and manganese are precipitated in the filtrate as hydroxides by addition of calcium chloride. Zinc is then precipitated as the sulfide with TAA, while nickel and chromium remain in solution. After the precipitate has been dissolved zinc is determined by chelatometric titration with EDTA. As little as 0.6 mg of zinc can be determined in presence of a large excess of other group II and group III elements.

The Quantitative Determination of Zinc in Transparent Rubber Articles

Abstract The method to be described is particularly suitable for the quantitative determination of zinc, present in the form of zinc oxide or of zinc salts, in transparent rubber articles. Rubber articles of this type contain very small quantities of zinc compared with the quantities present in non-transparent rubber articles, in fact the lower limit is only 0.05 per cent, i.e., only about one-hundredth as much as the normal content. The analytic determination of the zinc content when present in such extremely low percentages as this is extremely difficult by ordinary, methods, and even with higher but nevertheless small percentages of zinc, the use of relatively large quantities of material is necessary and the analytical results are often far from precise. The ordinary method of incineration in a porcelain crucible does not lend itself to the isolation of small quantities of zinc because the latter is easily fixed by the silica of the crucible. On the other hand incineration in a platinum crucible is not suitable because of the tendency of this metal to form a carbide in contact with the carbonaceous substances in the rubber. The novel feature of the method of analysis to be described is the procedure for obtaining a solution of the inorganic substances in the rubber. This involves destruction of the rubber by concentrated sulfuric acid and subsequent oxidation of the organic residue by concentrated nitric acid. This gives a solution of the zinc in the form of sulfate. It is then isolated as zinc sulfide and is redissolved and determined volumetrically by the already known method of precipitation with a standard solution of potassium ferrocyanide. The most suitable concentration, acidity and temperature to give precise results by this procedure for low percentages of zinc in rubber were established.

Determination of zinc and copper with morpholine

In morpholine has been found an organic base which is useful as an analytical reagent, and may serve for the purpose of quantitative determination of zinc and copper. In both cases, the analytical procedure is of a very simple nature, and yields good results. Morpholine may be useful for the separation of amphoteric ions of electropositive character from those of electronegative character.