Features of sodium determination in dilute mixed solutions with phenylalanine by flame photometry

Flame spectrophotometry is one of the main methods for determining alkali and alkaline earth metals in solutions. Chemical analysis by the flame photometric method have become of great importance for estimation of trace elements content and for work on small quantities of sample. The most important disadvantages of flame spectrophotometry are different types of interference (spectral, chemical, and physical). The paper considers mainly the physical interference which directly relates to the state of the sample itself and includes solution temperature, viscosity, surface tension, and vapor pressure. These effects are interdependent and not easily isolated for study. The addition of a substance increases the viscosity of the solution, which affects aerosol formation, transport, droplet size distribution, evaporation rate and flame temperature. All that leads to a decrease in the intensity of light emission. In the present article, the effect of phenylalanine on the sodium determination by the flame photometric method in the field of dilute solutions was studied. A decrease in the photocurrent emission of sodium in its joint determination with phenylalanine was found. The main reason is the increase in viscosity. It leads to a reduction in the spraying rate in the analyzer and a diminution in the analytical response of the device. The systematic type of errors in determining the concentration of sodium in the presence of phenylalanine is proved.

Mineral profiles of powdered milk, yoghurt, ice cream and raw milk

The present study was undertaken to update the dairy food composition database of Bangladesh by studying the minerals profile of important milk and milk products. Major minerals such as Sodium (Na), Potassium (K), Calcium (Ca), Magnesium (Mg) and Phosphorus (P) contents of powdered milk, yoghurt, ice cream and raw milk of cows were investigated in this study. The research was conducted at the postgraduate laboratory of Dept. of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh. Na and K content were found by flame spectrophotometry method, Ca and Mg by EDTA titrimetric method and P by UV-visible spectrophotometric determination. One Way ANOVA (with ‘p’ values) was done by using statistical analytical software Stata 12. ANOVA was coupled with Tukey’s test that gives mean separation in case of significant difference among the samples. Concerning mean values, powdered milk contained the highest Na (3138.19 ppm), K (9394.47 ppm), Ca (7615.2 ppm), Mg (891.18 ppm) and P (11332.36 ppm), whereas, the lowest Na (93.09 ppm), K (463.39 ppm) and Ca (1362.72 ppm) were found in raw milk and the lowest Mg (267.35 ppm) and P (1673.99) were found in ice cream. Elemental composition varied significantly from product to product (p<0.05). From this study it could be concluded that major minerals are found highest in powdered milk and lowest in raw milk, whereas, yoghurt and ice cream contained intermediate level of minerals.Asian J. Med. Biol. Res. June 2017, 3(2): 294-297

Metrological assessment of TDR performance for measurement of potassium concentration in soil solution

ABSTRACT Despite the growing use of the time domain reflectometry (TDR) technique to monitoring ions in the soil solution, there are few studies that provide insight into measurement error. To overcome this lack of information, a methodology, based on the central limit theorem error, was used to quantify the uncertainty associated with using the technique to estimate potassium ion concentration in two soil types. Mathematical models based on electrical conductivity and soil moisture derived from TDR readings were used to estimate potassium concentration, and the results were compared to potassium concentration determined by flame spectrophotometry. It was possible to correct for random and systematic errors associated with TDR readings, significantly increasing the accuracy of the potassium estimation methodology. However, a single TDR reading can lead to an error of up to ± 18.84 mg L-1 K+ in soil solution (0 to 3 dS m-1), with a 95.42% degree of confidence, for a loamy sand soil; and an error of up to ± 12.50 mg L-1 of K+ (0 to 2.5 dS m-1) in soil solution, with a 95.06% degree of confidence, for a sandy clay soil.

Potassium distribution in drip irrigation with fertigation for different injection distances in the main line

The purpose of this research was to evaluate the K2O distribution uniformity by surface drip irrigation at Universitat Politecnica de Valencia, Valencia, Spain (39º 29′ N, 0º 23′ W, 20 m). The irrigation was performed by drip lines with not-compensated emitters, spaced 0.3 m. The fertigation was realized using a fertilizer injector pump of electric action with injection of 0.25 h. The experimental design used completely randomized blocks with five treatments and four replications. The treatments consisted of injection in five distances, located at 10; 20; 30; 40; 50 m of the first drip line. Samples were collected in emitters located at the start, at 1/3, at 2/3 and at the end of the drip lines. The nutrient concentration was determined by flame spectrophotometry. The Christiansen's uniformity coefficients (CUC), of distribution (DUC), of statistical (SUC) and of emission (eUC) were estimated. The K2O concentration and distribution decreased linearly with the increase of the injection distance. In all treatments, the CUC, SUC and DUC were described as 'excellent'. The eUC was described as 'recommended' only at smaller injection distances.

Relationships between Maternal and Fetal Liver Copper, Iron, Manganese, and Zinc Concentrations and Fetal Development in California Holstein Dairy Cows

Associations between maternal trace element deficiencies and abortion have been made for many mammalian species. Objectives of this study were to estimate and correlate maternal and fetal hepatic Cu, Fe, Mn, and Zn concentrations through gestation. Additionally, aborted fetuses, stratified by cause of abortion (infectious or noninfectious), were compared to size-matched nonaborted fetuses to examine for magnitude and direction of change in hepatic trace element status. Dam and fetal liver were removed at slaughter from 103 Holstein dairy cows judged grossly normal by ante- and postmortem examination. Liver samples were collected from fetuses submitted by veterinarians for routine diagnosis of abortion (n = 80). Hepatic Cu, Fe, Mn, and Zn concentrations were determined by flame spectrophotometry. Comparisons of groups, estimations of correlations, and derived prediction equations were made by least-squares methods. Maternal liver Cu, Fe, Mn, and Zn concentrations did not vary during gestation. Compared with the dam, fetal liver Fe and Zn concentrations were higher ( P < 0.05), fetal Cu concentrations were similar ( P > 0.05), and fetal liver Mn concentrations were lower ( P < 0.05). As fetal size increased, fetal liver Cu and Zn concentrations increased (P < 0.05), fetal liver Fe concentration decreased ( P < 0.05), and fetal liver Mn did not change ( P > 0.05). Aborted fetuses had lower liver Cu, Mn, and Zn concentrations than did nonaborted fetuses ( P < 0.05). Liver Fe concentration was lower in aborted fetuses than in nonaborted fetuses in the second trimester only ( P < 0.05). Consistently lower liver Cu, Fe, Mn, and Zn concentrations in aborted fetuses suggest a nonspecific change in trace element status, which implies an effect of abortion, not a cause of abortion.

Micromethods for the Simultaneous Measurement of Intracellular Potassium and Corticosterone Output of Isolated Adrenal Cortical Cells

1. A technique is described for the measurement of potassium and water spaces in less than 1 μ1 of packed cells. 2. The total potassium content of cell pellets is measured in a perchloric and nitric acid extract by flame spectrophotometry. The potassium in trapped medium is estimated from the distribution space of hydroxy[14C]methylinulin and subtracted from the total potassium content to give intracellular potassium content. Corticosterone output was measured by radioimmunoassay. 3. The simultaneous measurement of total water from the [3H]water space allows calculation of the intracellular water space. 4. Values obtained for intracellular potassium content, intracellular water space and calculated intracellular potassium concentration are presented for different preparations of isolated adrenal cortical cells.