Sodium chloride concentrations

The average composition of seawater is shown in Table 1-3. Seawater muds have sodium chloride concentrations above 10,000 ppm. Most of the hardness in seawater is caused by magnesium. 

Figure 7. Effect of sodium chloride concentration on the viscosity of hydrolyzed poly(starch g-(2 propenamide)) copolymer solutions.

TITRATIONS FOR COMPARISON OF METHODS. The automated photometric and turbidimetric methods were compared using 30 cm3 samples of surfactant solution containing a nominal 20 mol SDBS to give an equivalence volume of 5 cm3. The effect of salinity on the titrations was studied using samples prepared containing sodium chloride concentrations of 0.0, 0.14, 0.70 and 1.46 wt%. The influence of the choice of filter (580 or 620 nm) was also investigated. 

Effect of NaCI Concentration. The presence of surfactant in brine can have a dramatic effect on crude oil-aqueous surfactant tensions even at elevated temperatures r5,211. Figure 5 shows that the effect of sodium chloride concentration on Athabasca bitumen-D20 interfacial tensions measured at constant surfactant... 

It is interesting to compare these results with the electrophoretic measurements made under identical electrolyte concentrations. Figure 8 shows that the variation of electrophoretic mobility with sodium chloride concentration is different for the bare and the PVA-covered particles. For the bare particles, the mobility remains constant up to a certain salt concentration, then increases to a maximum and decreases sharply, finally approaching zero. The maximum in electrophoretic mobility-electrolyte concentration curve with bare particles has been explained earlier (21) by postulating the adsorption of chloride ions on hydrophobic polystyrene particles. In contrast, for the PVA-covered particles, the mobility decreases with increasing electrolyte concentration until it approaches zero at high salt concentration. 

With increasing electrolyte (sodium chloride) concentration there appears to be a slight increase (within experimental error) in adsorption among the lower M.S. nonionic cellulose... 

The presence of anionic or cationic groups at a 0.4 M.S. level inhibited adsorption and interlayer entrapment of 2.0 M.S. hydroxyethyl cellulose(HEC) from fresh water solutions. The lack of adsorption of the cationic HEC is surprising it is related to hydration of the quaternary amine group. Increasing adsorption and interlayer entrapment is observed with both the cationic and anionic HECs with increasing sodium chloride concentration. 

Carr [562] has studied the effects of salinity on the determination of strontium in seawater by atomic absorption spectrometry using an air-acetylene flame. Using solutions containing 7.5 mg/1 strontium and between 5 and 14% sodium chloride, he demonstrated a decrease in absorption with increasing sodium chloride concentration. To overcome this effect a standard additions procedure is recommended. 

FIGURE 1.46 Effects of major experimental variables (A) extraction time, (B) pH, (C) sodium chloride concentration, and (D) temperature on the efficiency of direct SPME of anticonvulsants in plasma sample.1 7 (Reproduced with permission from the authors.)... 

The unit operation demonstrates that membrane life over two years has been demonstrated and that the selected materials of construction are correct. The recovery of sulphate-lean brine is 85-90% during normal operation. In a trial run under extreme conditions, with the unit modified to operate in recycle mode, the concentration of sodium sulphate in the reject stream was increased to 190g l-1 a 90% sulphate rejection rate was achieved during this trial. The sodium chloride concentration decreased on the concentrate side of the membrane and increased in the... 

Figure 19.9. Chromatogram for stepwise elution of bovine serum albumin on a Vistec diethyl aminoethyl cellulose ion-exchanger, using stepwise increases in sodium chloride concentration in the mobile phase to achieve selective desorption. Proteins 1, serum fraction not adsorbed by column (includes y-gobuhn) 2,3,...

Feed solution used in all experiments contained sodium chloride at a concentration level of 5,000 ppm. Membrane salt rejection is evaluated from conductance measurements of product water and expressed as percent rejection, %R, or desalination ratio, D. . These units are defined by the following equations in which Cp and Cf are sodium chloride concentrations in feed and product respectively. Note that D. is very sensitive to concentration changes and expands rapidly as 100% rejection is approached. 

The reverse osmosis membranes were tested in the standard experimental set-up (10). The experiments were carried out at three different pressures 17.4, 40.8 and 102 bars the corresponding sodium chloride concentrations were 3500 ppm, 5000 ppm and 29000 ppm. Before the reverse osmosis runs, membranes were thermally shrunk for 10 minutes in water and subsequently pressurized at 15-20% higher pressures than those used during the reverse osmosis experiments. A feed flow rate of 400 ml/mln was used giving a mass transfer coefficient k = 40 x 10 cm/s on the high pressure side of the membrane. 

Fig. 19. Zero-shear viscosity of aqueous xanthan solutions at different sodium chloride concentration C, [140]...

Data in Figure 6 show the effect of varying the pH and sodium chloride concentration on emulsion capacity of peanut protein isolate. Shifting the pH to levels above or below the isoelectric point improved emulsion capacity of peanut protein isolate in O.IM or 0.2M NaCl. Similar trends were noted when distilled water was used as the continuous phase (data not.shown). At the 0.5M NaCl concentration, however, little difference was noted in emulsion capacity at pH 3, 4, or 5 appreciable increases occurred when the pH was raised to 6 and above. At the highest salt concentration (1.OM NaCl), a gradual increase in emulsion capacity occurred when the pH was increased from 3 to 10. An overall suppression in emulsion capacity occurred as salt concentration increased except at pH 5 and 6. These emulsion-capacity curves closely resemble the protein-solubility curves of peanut protein shown in Figure 7... 

For the distribution coefficients, an acetate buffer adjusted to pH 5 was used and the sodium chloride concentration of it varied from 0.25 to 4 M by dissolving sodium chloride in the buffer. Aliquots of the Es solution were mixed with the buffer and a weighed quantity of the solid clay was mixed with this solution. 

Chemical complexing-solvent extraction studies were conducted using aliquots of synthetic effluents which contained varying quantities of Hs PbCl and (C2H5)3NCSSNa 3H20 with the sodium chloride concentration maintained at 0.83 m. 

The initial aqueous phase concentration of triethyl lead chloride was approximately 20 ppm, determined accurately in each case. The sodium chloride concentration was maintained at 0.83 m and the reagent-to-lead ratio, Cr/Cl at 3.0, thus ensuring complexing at the phase ratio employed, Vaq/Vorg = 2.0. The volume of the aqueous phase was 400 ml, and that of the organic phase, xylene, 200 ml. The extraction, conducted at ambient conditions of 16-18°C, was followed by a determination of the concentration of triethyl lead in the aqueous phase at time intervals up to 150 min. 

In order to examine the influence of sodium chloride concentration on the distribution of triethyl lead chloride between an organic and aqueous phase, distribution studies were initiated. The solvent chosen for the initial studies was benzene because it had been shown that up to 30% of triethyl lead chloride is transferred to the organic phase as the neutral species Hs PbCl0 when using the chemical complexing-solvent extraction technique. 

Figure 8. 23Na quadrupole splittings as a function of the sodium chloride concentration in the water layer for lamellar mesophase samples composed of 75% dimyristoyllecithin and aqueous salt solutions accounting for 25% of the total weight... 

Figure 10. Water deuteron quadrupole splitting as a function of sodium chloride concentration for the same samples as in Figure 8...

Fig. 6.25 Dual ion-sensitive field-effect transistor (ISFET) for measurement of sodium chloride concentration...

Figure9.5 shows the relationship between the logarithm of the obtained impedance at the completion of the semi-circle (right-hand side of the semicircle in Fig. 9.2) as a function of the logarithm of the sodium chloride concentration. A linear relationship is observed with good correlation coefficient and a slope of -1, indicating that the relationship between the impedance (R) and the electrolyte concentration (c) is reciprocal. Therefore Equation9.1 can be re-defined to ...

This is most simply prepared by the addition solid NaCl to 0.05 M phosphate buffer pH 6.3. This will alter the pH and concentration of the phosphate, but in this case it will not affect the procedure because the critical factor is the sodium chloride concentration. 

When Bilan et al. [26] fractionated the crude fucoidan of Fucus evanescens by ion-exchange chromatography on DEAE-Sephacel, using aqueous sodium chloride of increasing sodium chloride concentration as eluent, a fraction which was essentially a homofucan sulfate was isolated. This homofucan was shown to contain a linear backbone of alternating 3- and 4-linked-a-L-fucopyranose 2-sulfate residues. Also, some additional sulfation was observed on C-4 of the 3-linked residues, whereas a part of the remaining hydroxyl groups was randomly acetylated. 

F. Pinguet, et al., Effect of sodium chloride concentration and temperature on mel-phalan stability during storage and use. Am. J. Hosp. Pharmacol. 51 2701-2704, 1994. 

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