Trisodium Citrate Concentration Research Articles

Attachment of gold nanoparticles onto indium tin oxide surfaces controlled by adding citrate ions in a seed-mediated growth method

A simple approach to control the attachment of gold nanoparticles (AuNPs) onto the indium tin oxide (ITO) surfaces is reported. Adjusting the concentration of trisodium citrate in the Au colloid solution for the seeding process from 1 to 50 mM in the seed-mediated growth method, the dramatic changes in the SEM images and actual color were observed indicating the changes in nanostructures of AuNPs formed on the ITO surfaces. Whereas the attachment of smaller AuNPs with higher density were observed when 25 mM citrate ions were added in the seed solution, larger AuNPs were observed to attach at 50 mM. On the basis of this difference and the surface SEM images observed just after seeding, the roles of citrate ions were discussed. Consequently, it was inferred that the citrate ions affected the growth process as well as the seeding process. The repulsive power expected from the increased negative charges of citrate ions were not significant, but rather the dense attachment was promoted as the peculiar effect of citrate ions. Such control of the AuNPs attachment on ITO would be practically effective because the dense attachment can be performed by just changing the composition of the seed solution.

Effect of Formulation and Manufacturing Parameters on Process Cheese Food Functionality—I. Trisodium Citrate

The objective of this research was to use a Rapid Visco Analyzer to study the effect of natural cheese age, trisodium citrate (TSC) concentration, and mixing speed on process cheese food (PCF) functionality. In this study 3 replicates of natural cheese were manufactured, and a portion of each cheese was subjected to 6 different PCF manufacturing treatments at 2, 4, 6, 12, and 18wk of ripening. These treatments were factorial combinations of 3 levels of TSC (i.e., 2.0, 2.5, and 3.0%) and 2 mixing speeds during manufacture (450 and 1,050rpm). Functional properties of the PCF evaluated included manufacturing properties [apparent viscosity after manufacture (VAM)], unmelted textural properties (firmness), melted cheese flow properties [hot apparent viscosity (HAV)], and cheese thickening during cooling [time at 5000cP (T5)]. All 4 parameters (VAM, firmness, HAV, and T5) were significantly affected by natural cheese age and mixing speed, whereas VAM, HAV, and T5 were also significantly influenced by the amount of TSC. The VAM and firmness decreased as cheese age increased, whereas T5 values increased as cheese age increased. Similarly, VAM, HAV, and firmness values increased because of the increased mixing speed, whereas T5 values decreased. The age×mixing speed interaction was significant for VAM and firmness. The age×concentration of the TSC interaction term was significant for VAM, whereas the age×age×TSC concentration term was significant for HAV. The results demonstrate that natural cheese age, mixing speed during manufacture, and concentration of TSC have a significant impact on process cheese functionality.

Effect of Trisodium Citrate Concentration and Cooking Time on the Physicochemical Properties of Pasteurized Process Cheese

The effects of the concentration of trisodium citrate (TSC) emulsifying salt (0.25 to 2.75%) and holding time (0 to 20min) on the textural, rheological, and microstructural properties of pasteurized process Cheddar cheese were studied using a central composite rotatable design. The loss tangent parameter (from small amplitude oscillatory rheology), extent of flow (derived from the University of Wisconsin Meltprofiler), and melt area (from the Schreiber test) all indicated that the meltability of process cheese decreased with increased concentration of TSC and that holding time led to a slight reduction in meltability. Hardness increased as the concentration of TSC increased. Fluorescence micrographs indicated that the size of fat droplets decreased with an increase in the concentration of TSC and with longer holding times. Acid-base titration curves indicated that the buffering peak at pH 4.8, which is due to residual colloidal calcium phosphate, decreased as the concentration of TSC increased. The soluble phosphate content increased as concentration of TSC increased. However, the insoluble Ca decreased with increasing concentration of TSC. The results of this study suggest that TSC chelated Ca from colloidal calcium phosphate and dispersed casein; the citrate-Ca complex remained trapped within the process cheese matrix. Increasing the concentration of TSC helped to improve fat emulsification and casein dispersion during cooking, both of which probably helped to reinforce the structure of process cheese.

Effects of Two Types of Emulsifying Salts on the Functionality of Nonfat Pasta Filata Cheese

Effects of 2 types of emulsifying salts (ES) on the functionality of nonfat pasta filata cheese were examined. Nonfat pasta filata cheese was made from skim milk by direct acidification. Trisodium citrate (TSC) and tetrasodium pyrophosphate (TSPP) were added to curds (at 1, 3, and 5%, wt/wt) at the dry-salting step, together with glucono-δ-lactone to maintain a constant pH. When TSC was added, there were no significant compositional differences, although insoluble Ca and P contents significantly decreased with the addition of TSC. When TSPP was added, fat content was not significantly different, but protein content decreased with increasing concentrations of TSPP. Both insoluble Ca and P contents increased with the addition of 1% TSPP. The addition of ES affected textural and functional properties. With increasing concentrations of TSC, meltability increased, whereas increasing the TSPP content decreased meltability. Cheese made with 1% TSC had better stretchability compared with control cheese. However, the addition of more than 3% TSC decreased stretchability. Addition of TSPP caused a considerable decrease in stretchabilty. Scanning electron microscopy revealed that the size and number of serum pockets decreased and protein appeared more hydrated with the addition of both ES. These results suggested that TSC and TSPP influenced the functionality of nonfat pasta filata cheese differently; that is, the effects of TSC were probably caused by a decrease in the number of colloidal calcium phosphate cross-links and an increase in electrostatic repulsion, whereas the effects of TSPP may have been related to the formation of new TSPP-induced casein-casein interactions.

Effects of Emulsifying Salts on the Turbidity and Calcium-Phosphate–Protein Interactions in Casein Micelles

Influence of emulsifying salts (ES) on some physical properties of casein micelles was investigated. A reconstituted milk protein concentrate (MPC) solution (5% wt/wt) was used as the protein source and the effects of ES [0 to 2.0% (wt/wt)] were estimated by measuring turbidity, acid-base titration curves and amount of casein-bound Ca and inorganic P (Pi). Various ES, trisodium citrate (TSC), or sodium phosphates (ortho-, pyro-, or hexameta-) were added to MPC solution, and all samples were adjusted to pH 5.8. Acid-base buffering curves were used to observe changes in the amount and type of insoluble Ca phosphates. An increase in the concentration of TSC added to MPC solution decreased turbidity, buffering at pH ∼5 (contributed by colloidal Ca phosphate), and amount of casein-bound Ca and Pi. Addition of up to 0.7% disodium orthophosphate (DSP) did not significantly influence turbidity, buffering curves, or amount of casein-bound Ca and Pi. When higher concentrations (i.e., ≥1.0%) of DSP were added, there was a slow decrease in turbidity. With increasing concentration of added tetrasodium pyrophosphate (TSPP), turbidity and buffering at pH ∼5 decreased, and amount of casein-bound Ca and Pi increased. When small concentrations (i.e., 0.1%) of sodium hexameta-phosphate were added, effects were similar to those when TSPP were added but when higher concentrations (i.e., ≥0.5%) were added, the buffering peak shifted to a higher pH value, and amount of casein-bound Ca and Pi decreased. These results suggested that each type of ES influenced casein micelles by different mechanisms.

Role of Citrate Ions in the Phosphonate-based Inhibitor System for Mild Steel in Aqueous Chloride Media

The corrosion inhibition efficiency of phosphonic acid and its derivatives for the inhibition of corrosion of mild steel in neutral chloride media is decided by its ability to form protective film over the surface. In this context, the effect of addition of metal cations and certain organic compounds, such as citrate in conjugation with phosphonic acid to impart synergistic corrosion inhibition has been explored. The experiments were carried out using various concentrations of trisodium citrate and zinc ions in an aqueous solution of 2-carboxyethyl phosphonic acid (2CEPA) at 25 ppm. The corrosion characteristics have been determined using electrochemical impedance spectroscopy together with determination of corrosion rate by weight-loss method. It has been observed that a combination of inhibitive ions, namely citrate, ZCEPA, and zinc ions at 25 ppm gives 96 per cent inhibition efficiency and this corrosion inhibition is due to the formation of a protective film. By increasing the concentration of citrate beyond 25 ppm, the corrosion inhibition efficiency decreases. This paper discusses the role of citrate and zinc ions in imparting added corrosion inhibition ability using 2CEPA on the basis of experimental results.

Ethanol/Trisodium citrate for hemodialysis catheter lock

The objective of this study was to confirm the compatibility of ethanol and 4% trisodium citrate (TSC) for potential use as a catheter locking solution. Increasing concentrations of ethanol were combined with 4% TSC in glass test tubes and stored at 37 degrees C over 72 hours. Each tube was visually inspected to determine the highest compatible concentration. To confirm visual compatibility, HPLC analysis was used to compare the concentration of TSC in control solutions (n = 6) to solutions containing both TSC and the highest concentration of ethanol that was visually compatible (n = 6). Compatibility in carbothane hemodialysis catheters was then confirmed in vitro. Results of the compatibility tests indicated that 30% ethanol was the maximum concentration visually compatible with 4% TSC. Ethanol concentrations of 35% or above form a crystalline precipitate in the glass test tubes within 72 hours. HPLC analysis showed no difference in the concentration of TSC in the control solutions compared to the TSC/ethanol solutions when incubated in glass test tubes. A slight, but statistically significant increase in the TSC concentration (1.27%; p < 0.0001) was observed when the ethanol/TSC solution was incubated in carbothane hemodialysis catheters. This slight increase may be due to ethanol absorption into the catheter polymer. Further studies are underway to determine if an ethanol/TSC lock affects the mechanical properties of these carbothane hemodialysis catheters. We conclude that 30% ethanol is compatible with 4% trisodium citrate in carbothane hemodialysis catheters in vitro. Until the lock's affect on carbothane hemodialysis catheters is known, it cannot yet be recommended for clinical use.

Morphology-Control in Microwave-Assisted Synthesis of Silver Particles in Aqueous Solutions

Abstract The morphologies of Ag particles can be controlled between distorted sphere and prism by employing microwave-promoted reductions of highly concentrated 0.1 M silver nitrate in aqueous solutions. We can selectively synthesize either sphere-Ag or prism-Ag particles by changing only an additive, i.e., either trisodium citrate/formaldehyde or poly(N-vinyl-2-pyrrolidone) (PVP). The particle sizes and size distributions of sphere-Ag particles are strongly dependent on the concentration of trisodium citrate.

Arsenic extractability with phosphate and citrate from peat collected in Bangladesh

Arsenic extractability with various solutions from peat samples collected in Deuli Village, Bangladesh, was investigated to reveal the leaching mechanisms of arsenic in sediments to groundwater. Peat layer was distributed at the depth of 7–8 m in the sediments, and the peat samples collected and used in this experiment contained 137 mg kg−1 arsenic. A wide range of pH values and concentrations of phosphoric acid and trisodium citrate was used for the extracting solutions. Arsenic extractability with Hel (25–1,000 mM) or NaOH (20–500 mM) at different pH values ranged for 30 to 60% in strong acid or alkali, while was less than 0.1% in the neutral pH range against the total content. Extraction of arsenic with 100 mM phosphoric acid and 100 mM trisodium citrate was about 20% even at a neutral pH, while the extractability with these solutions at concentrations below 1 mM was similar to that with distilled water. These results suggest that competitive exchange and / or chelating action are / is the prior possible mechanism for arsenic leaching from peat. However, the experimental conditions such as pH value or phosphate anion concentration differed from those in the study area where the pH of groundwater was almost neutral and the phosphate anion concentration was only 0.01 mM. Moreover, since the experiment was conducted using a batch system under oxidative conditions and not using a continuous flow system, the importance of the oxidation-reduction potential in the sediments and organic matter content in the groundwater should be investigated.

Effects of ligands on electroless Ni–P alloy plating from alkaline citrate–ammonia solution

Electroless Ni–P deposits with a wide range of phosphorus contents (from ∼2 to 13 wt.%) at higher deposition rates have been obtained from alkaline solutions containing tri-sodium citrate and ammonium chloride by controlling the tri-sodium citrate concentration. X-ray fluorescence analysis, XRD, SEM and polarization curves were used to characterize the compositions, structures, morphologies and anti-corrosion properties of these Ni–P coatings, respectively. Systematic UV–Vis absorption measurement shows the presence of a ternary nickel citrate–ammonia complex in alkaline electroless baths, which supports the explanation of a proposed mechanism involving a ternary complex as the discharge species.

分光光度計による金コロイド生成過程の追跡

The formation of colloidal gold produced from hydrogen tetrachloroaurate by three kinds of the reducing agents is studied by using a spectrophotometer. The absorption due to gold sol formation appeared in the 500 to 600nm wavelength. When tri-sodium citrate is used as a reducing agent, the wavelength of maximum absorbance due to colloidal gold shifts from high to low values and approaches to a constant value of 525nm. It apparently indicates that the particle size decreases over the course of the reaction. The reaction rate of the formation of gold sol decreases with the increase in the tri-sodium citrate concentration. Howerer, when citric acid or 1, 3-acetone dicarboxylic acid is used, the wavelength of maximum absorbance is almost constant at 525nm, and the reaction rate increases as a function of the reducing agent. The reason of the difference in these results could not be found in this work, so it might be necessary to study the citrate anion absorption of the surface of gold sol or the complex formation between citrate and gold ions.

Effect of Concentration of Trisodium Citrate Anticoagulant on Calculation of the International Normalised Ratio and the International Sensitivity Index of Thromboplastin

The aim of this study was to determine whether the concentration of trisodium citrate used to anticoagulate blood has an effect on the INR of the sample and the ISI of the thromboplastin. Five thromboplastins including and Australian reference material were used to measure the prothrombin time of normal and patient samples collected into two concentrations of trisodium citrate--109 mM and 129 mM. There was no effect of citrate concentration on the INRs determined with the reference material. However for the other four thromboplastins there was a significant difference between INRs for the two citrate groups. The prothrombin times of the samples collected into 129 mM were longer than those collected into 109 mM. This difference was only slight in normal plasma but more marked in patients receiving oral anticoagulants, causing the INRs for patient plasmas collected into 129 mM citrate to be higher then the corresponding samples collected into 109 mM citrate. From orthogonal regression of log prothrombin times by the reference method against each thromboplastin, we found that the ISI for each thromboplastin was approximately 10% lower when determined with samples collected into 129 mM citrate than with samples collected into 109 mM. These results suggest that the concentration of trisodium citrate used for collection of blood samples can affect the calculation of the INR and the calibration of the ISI of thromboplastin. This was found both for commercial thromboplastins prepared by tissue extraction and for a recombinant tissue factor.

Effect of trisodium citrate treatment on hybridoma cell viability

Trisodium citrate has been widely used to dissolve calcium alginate beads in order to estimate cell concentration in the beads. To obtain an accurate measurement of viable cell concentration in calcium alginate beads, the effect of trisodium citrate solutions on hybridoma cell viability was studied with regard to stage of growth and trisodium citrate concentration. The cells in the decline phase of growth were more sensitive to 30 minutes of trisodium citrate treatment than the cells in the exponential phase of growth. The cell viability did not decrease rapidly during citrate treatment regardless of cell growth phase and trisodium citrate concentration in the range of 1–1.5%. By using the commercially available sodium alginate, Keltone LV, dissolution time can be kept short enough (below 5 minutes) to keep the effect of trisodium citrate negligible to cell viability.

Gastric and Intestinal Transit in Rats Measured by a Radioactive Test Meal

Abstract Measurements of the passage of a Ba 133 SO 4 test meal through the stomach and small intestine of the rat were made under various test conditions and after drug treatment. These measurements consisted of: (1) the percentage of the total Ba 133 SO 4 emptied by the stomach and each successive segment of the small intestine; (2) the ratio of the output from a given segment to its input, the intestinal transit ratio; and (3) the emptying half-time. The passage of the meal was influenced by the volume of meal administered, the body weight of the test animals, and by the concentration of trisodium citrate in the meal. Drugs which enhanced cholinergic mechanisms enhanced emptying also, e.g., methacholine, insulin, 2-deoxy-D-glucose, metoclopramide, and reserpine. Atropine, an anticholinergic, delayed emptying. The following drugs also delayed emptying, e.g., morphine, oxethazaine, chlorpromazine, and the ganglionic blocking drug Ntert-butyl-1-4-butanediamine. The mechanisms controlling stomach emptying and intestinal propulsion were differentially influenced by several of the drugs studied.