Sodium/ammonium concentration ratio

Figure 7. Ion chromatographic separation of ammonium ion (3) from sodium (1) and calcium (2) ions with a concentration ratio of sodium to ammonium of 60,000 1. Column Dionex CS15 eluent sulfuric acid and 18-crown-6. (from ref. 32)...

Fig. 7. Dependence of conversion %) over 30 min on sodium Blkylsutfonate concentration in potymenzation of (l) methyl acrylate end (2) butyl metliacTylBte. Ammonium persulfate, 0j0I% (l) and 0.1% (2) in aqueous phase T, 60 C phase ratio, I i.5.

Fig- 20- Dependence of the polytneiizalion rate (jR tnol/dm sec) of (1) methyl acrylate (2) ethyl acryiate (3) butyl acryiate (4) hexyl acrylate and (S) styrene on sodium dodecylsulfate concentration. Ammonium peisulfete 0.025% in aqueous phase phase ratio 1 4 T 60%. 

The original M0/WO3 concentration ratio in the feed solution of 0.06-0.84% decreases to 0.001-0.015% in the effluent. The recovery of the operation is better than 99%. It was used in 1992 commercially to produce sodium and ammonium tungstate of high purity. The purification effect is demonstrated by the analyses in Table 5.5. 

A quality feature of all cation exchangers suitable for simultaneous analysis of mono- and divalent cations is the maximal concentration ratio between sodium and ammonium that allows a separation of both components. Under isocratic conditions with lOmmol/L methanesulfonic acid at 2mL/min, lonPac CS12... 

Figure 10.19 Separation of very disparate rate 1 mlVmin detection suppressed conduc-concentration ratios of sodium and ammo- tivity injection volume 25 pL peaks 100 mg/L nium. Separator column lonPac CS16 column sodium (1) and 0.01 mg/L ammonium (2). dimensions 250 mm x5 mm i.d. column temperature 40 °C eluent 30 mmol/L MSA flow...

Rey, M.A., Riviello, J., Pohl, C., and Jagodzinski, J. (1997) Dealing with high-to-low concentration ratios of sodium and ammonium in ion chromatography. Presentation at the Pittsburgh Conference, Atlanta, GA, USA. 

Figure 9-22 illustrates the separation between sodium and ammonium with a concentration ratio of 4000 1, obtained on a weak acid cation exchanger modified with carboxylate-, phosphonate- and crown ether groups. The higher selectivity of this stationary phase towards ammonium and potassium ions can be attributed to 18-crown-6, which was immobilized on the stationary phase surface... 

The fact that inorganic cations also play a role for the cell growth of microorganisms and for certain metabolic processes is often ignored. For example, alkali- and alkaline-earth metals as well as ammonium are needed at mmol/L concentrations to boost cell growth. Also, the concentration ratio between H+, Na, and K+ is of great importance for membrane physiology. However, the optimal concentration very much depends on the type of species and the cell density. Halophilic bacteria, for example, require sodium concentrations of more than... 

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