Determination of sodium

Kieber, R. J. Jones, S. B. An Undergraduate Laboratory for the Determination of Sodium, Potassium, and Ghloride, ... 

The alkah metals are commonly separated from all other elements except chlorine before gravimetric determination. In the absence of other alkaUes, sodium maybe weighed as the chloride or converted to the sulfate and weighed. WeU-known gravimetric procedures employ precipitation as the uranyl acetate of sodium—2inc or sodium—magnesium. Quantitative determination of sodium without separation is frequently possible by emission or atomic-absorption spectrometric techniques. 

Analytical Methods. A classical and stiU widely employed analytical method is iodimetric titration. This is suitable for determination of sodium sulfite, for example, in boiler water. Standard potassium iodate—potassium iodide solution is commonly used as the titrant with a starch or starch-substitute indicator. Sodium bisulfite occurring as an impurity in sodium sulfite can be determined by addition of hydrogen peroxide to oxidize the bisulfite to bisulfate, followed by titration with standard sodium hydroxide (279). 

DETERMINATION OF SODIUM ACYLISETHIONATE IN THE COMBI SOAP BY REVERSED - PHASE HIGH - PERFORMANCE LIQUID CHROMATOGRAPHY... 

France, D. M., R. D. Carlson, R. R. Rhode, and G. T. Charmoli, 1974, Experimental Determination of Sodium Superheat Employing LMFBR Simulation Parameters, Trans. ASME, J. Heat Transfer 9(5 359. (4)... 

In the indirect amperometric method [560], saturated uranyl zinc acetate solution is added to the sample containing 0.1-10 mg sodium. The solution is heated for 30 minutes at 100 °C to complete precipitation. The solution is filtered and the precipitate washed several times with 2 ml of the reagent and then five times with 99% ethanol saturated with sodium uranyl zinc acetate. The precipitate is dissolved and diluted to a known volume. To an aliquot containing up to 1.7 mg zinc, 1M tartaric acid (2-3 ml) and 3 M ammonium acetate (8-10 ml) are added and the pH adjusted to 7.5-8.0 with 2 M aqueous ammonia. The solution is diluted to 25 ml and an equal volume of ethanol added. It is titrated amperometrically with 0.01 M K4Fe(CN)6 using a platinum electrode. Uranium does not interfere with the determination of sodium. 

Allender, WJ. 1990. Determination of sodium fluoroacetate (compound 1080) in biological tissues. Jour. Anal. Toxicol. 14 45-49. 

Kimball, B.A. and E.A. Mishalanie.1993. Gas chromatographic determination of sodium monofluoroacetate as the free acid in an aqueous solvent. Jour. Chmmatogr. 634 289-296. 

Ozawa, H. and T. Tsukioka. 1987. Gas chromatographic determination of sodium monofluoroacetate in water by derivatization with dicyclohexylcarbodiimide. Anal. Chem. 59 2914-2917. 

A fiber optic sensor for the determination of sodium was reported by Burgess.<52) A bifurcated fiber with a reference fiber 5 mm apart from the tip was used to observe the changes of bromothymol blue (Amax = 620 nm) attached to Nafion in the presence of sodium ions. As the tip was saturated, the probe was renewed with fresh reagent. However, the epoxy holding the fibers was prone to damage from high sodium concentrations of around 2.5 M and the sensitivity of analysis was low. 

In this present work, an alternative PLS-2 method was investigated and applied to the determination of sodium benzoate (itsed for preservatives) artificial sweeteners Aspartame, Acesitlfame-K and caffeine in diet cola drinks. 

Noteworthy are the articles from Altria et al. and Assi et al. describing the robustness and validation of the determination of potassium as a counterion. An intercompany cross-validation of the determination of sodium in an acidic drug salt was also published. 

Chen, D., Klopchin, P., Parsons, J., and Srivatsa, C. S. (1997). Determination of sodium acetate in antisense oligonucleotides by capillary electrophoresis. /. Liq. Chromatogr. Related Technol. 20, 1185-1195. 

In addition to automated analysers for general use, sophisticated single purpose instruments have been developed and marketed, chiefly for clinical analyses (for example Astra 4 and Astra 8 from Beckman for the determination of sodium and potassium in blood or Orion Space-Stat SS-20 or SS-30 for the determination of calcium in blood). 

The results obtained with ISEs have been compared several times with those of other methods. When the determination of calcium using the Orion SS-20 analyser was tested, it was found that the results in heparinized whole blood and serum were sufficiently precise and subject to negligible interference from K and Mg ([82]), but that it is necessary to correct for the sodium error, as the ionic strength is adjusted with a sodium salt [82], and that a systematic error appears in the presence of colloids and cells due to complexa-tion and variations in the liquid-junction potential [76]. Determination of sodium and potassium with ISEs is comparable with flame photometric estimation [39, 113, 116] or is even more precise [165], but the values obtained with ISEs in serum are somewhat higher than those from flame photometry and most others methods [3, 25, 27, 113, 116]. This phenomenon is called pseudohyponatremia. It is caused by the fact that the samples are not diluted in ISE measurement, whereas in other methods dilution occurs before and during the measurement. On dilution, part of the water in serum is replaced by lipids and partially soluble serum proteins in samples with abnormally increased level of lipids and/or proteins. 

L. Lin and C.W. Brown, Near-IR spectroscopic determination of sodium chloride in aqueous solution, Appl. Spectrosc., 46, 1809-1815 (1992). 

Figure 4.13 — (A) Serially arranged ISEs for the simultaneous determination of sodium, potassium, calcium and chloride ions. (B) Serially and parallelly arranged ISEs for the simultaneous determination of T, Br", Cl and F . WE working electrode PC personal computer Ej-E r, Cr, Br" and F ISEs, respectively C C3 amalgamated-lead columns (1.5 and 2.5 cm long, respectively) AgCl column RE reference electrode PHM pH/mV-meter S sample injection CS carrier stream P pump R chart recorder W waste. (Reproduced from [126] and [127] with permission of Elsevier Science Publishers and Pergamon Press, respectively).

S.2.2.2 ICLS Example 2 This example discusses the determination of sodium hydroxide (caustic) concentration in an aqueous sample containing sodium hydroxide and a salt using NIR spearoscopy. An example of this problem in a chemical process occurs in process scrubbers where CO, is converted to Na,CO and H,S is converted to Na,S in the presence of caustic. Although caustic and salts have no distinct bands in the NIR, it has been demonstrated that they perturb the shape of the water bands (Watson and Baughman, 1984 Phelan et al., 1989)-Near-infrared spectroscopy is therefore a viable measurement technique. This method also has ad tages as an analytical technique for process analysis because of the stability of the instrumentation and the ability to use fiber-optic probes to multiplex tlie interferometers and Icx ate them rcm< >tely from the processes. 

Karube I, Okada T, Suzuki S, Suzuki H, Hikuma M, Yasuda T (1982) Amperometric determination of sodium nitrite by a microbial sensor. Eur J Appl Microbiol Biotechn 15 127-132... 

B.4 Determination of Sodium in Soil Extracts by Atomic Emission Spectrometry... 

The former process is reversible whereas the latter may lead to an irreversible deterioration of soil structure. Hence the determination of sodium in soil extracts is an important indicator of soil quality. A convenient method for the determination of sodium in soil extracts and other aqueous... 

Determination of sodium in a soil extract. Using the five sodium calibration standards already prepared obtain five replicate readings for each sodium standard and calculate the mean emission intensity and RSD for each standard. Aspirate the standards in ascending and descending order of concentration. Aspirate a blank between each standard and zero the instrument. Using a statistical software package construct a... 

What are the most probable sources of error in this experiment Does the method used offer an acceptable level of precision and accuracy for the determination of sodium in soil extracts and what are the reasons for your conclusions ... 

Sweet, D.V.W. Haartz, J.C. Hawkins, M.S. Determination of Sodium Hydroxide Aerosol in Industrial Hygiene Samples, unpublished work cited in ref. 1 personal communication (draft Report) by D.V. Sweet via G. Choudhary. 

Colorimetric Determination of Sodium Azide in Aqueous Ammonia (See under Manufacture of Sodium Azide)... 

Quantitative Determination of Sodium. — Introduce 10 gm. of sodium amalgam into 100 cc. of water, and allow the mixture to stand with repeated shaking until the evolution of hydrogen entirely ceases. Then titrate with normal hydrochloric acid, using methyl orange as the indicator. 

Quantitative Determination and Determination of Sodium Carbonate Content — Titrate the solution of 1 gnr. of sodium hydroxide in 100 cc. of water with normal hydrochloric acid in the cold, using phenolphthalein as indicator. At least 24 cc. of normal acid should be required to destroy the red color. Now add 1 drop of methyl orange, and titrate further until the color changes to red. In the second titration, at most 0.3 cc. of acid should be used (3.18 per cent of Na2C03). ... 

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