Deionization, water

Like strong acid resins, strong base resins are highly ionized and can be used over the entire pH range. These resins are used in the hydroxide (OH) form for water deionization. They will react with anions in solution and can convert an acid solution to pure water ... 

Although EDI may be used as a process for the production of basic pure water, in practice it suffers from the organic fouling potential of resins and the scale fouling potential of ED when higher TDS water sources are utilized. Appropriate pretreatment is therefore required. As a consequence, EDI is best suited for the production of very pure and ultrapure water by acting as a polisher to follow bulk water deionization by RO. Under these circumstances, it competes with both doublepass RO and MB units. 

Initial surfactant concentration was 0.50% wt in pH 8.5 solution. 50 g of test solution was placed over 100.0 g crushed Berea sandstone. The sample bottle was sealed and shaken continuously for 24 h at 75°C. The mixed indicator titration technique was used to determine active surfactant concentration before and after exposure of the test solution to crushed Berea sandstone. AS HAS, alkene.hydroxyalkanemonosulfonate ratio. D.I. water, deionized water. ND, not determined. 

See note a, Table 16. AS HAS, alkenerhydroxyalkanemonosulfonate ratio. D.I. water, deionized water. ND, not determined. b% branching of parent olefin. cAverage value + average deviation. 

Chlorhexidine base is not readily soluble in water therefore the freely soluble salts, acetate, gluconate and hydrochloride, are used in formulation. Chlorhexidine exhibits the greatest antibacterial activity at pH 7-8 where it exists exclusively as a di-cation. The cationic nature of the compound results in activity being reduced by anionic compounds including soap and many anions due to the formation of insoluble salts. Anions to be wary of include bicarbonate, borate, carbonate, chloride, citrate and phosphate with due attention being paid to the presence of hard water. Deionized or distilled water should preferably be used for dilution purposes. Reduction in activity will also occur in the presence of blood, pus and other organic matter. 

Preparation of Emulsions. The entire aqueous phase was stirred until all solids were dissolved. Sufficient water was withheld from the formulation so small volumes of experimental and control components could be added to emulsion subsamples. Sulfuric acid (1 N) was added to the aqueous phase to decrease the pH to 5.7. The two phases in separate containers were blanketed with nitrogen, sealed, and heated to 75 in an 80 water bath (about 30 minutes). The hot oil phase was stirred slowly and blanketed with nitrogen, then the hot aqueous phase was quickly added while stirring. The emulsion was blanketed with nitrogen and slowly stirred (about 2 hours) in the stoppered container until ambient temperature ( 25 ) was reached. Subsamples of the master batch were removed for the addition of experimental components and stored in 1-oz containers. The containers had been washed with hot tap water, deionized water, and methanol, then dried at 120 . 

Methanol, high purity Water, deionized or distilled Sodium chloride, high purity... 

Sodium azide is a powerful inhibitor of HRP, but sodium azide can be used with alkaline phosphatase conjugated antibodies without harmful effects. In addition, tap water or water deionized with polystyrene resins may inactivate the enzyme conjugate. Only use distilled, deionized water Tween-20 may interfere with some antibody-antibody reactions or may wash the protein of interest off the membrane. Tween-20 may be left out of the washes, but this may result in increased background... 

The efficiency of these steps can be conveniently monitored by continuous in-line measurement of the resistivity of the water (deionization results in increased resistivity, typically to levels of 1-10 MQ). If the resistivity of the deionized water falls below a value of approximately 1 MQ, automatic system shut-off, followed by regeneration of the anion and cation exchange beds (with NaOH and HCl respectively), is initiated. 

Component A Distilled TFA (1.0 mL) is added to HPLC grade water (deionized, 1L). Component B Distilled TFA (0.9 mL) is added to HPLC grade water/MeCN (40 60,... 

Water systems. The water systems at ABC Pharmaceutical Industries are monitored per manufacturing site SOP for Microbiological Monitoring of Water. The levels of water tested are city water, purified water (deionized water), and water for injection (WFI). Manufacturing site SOP describes the procedures for obtaining samples, sampling frequencies, test procedures, and acceptance criteria (alert and action limits). 

In the guide to inspections of topical products [28], it is indicated that water deionizers are usually excellent breeding areas for microorganisms, where flow rates, temperature, surface area of resin beds, and microbial quality of the feed water all influence microbial growth. Since topical products (e.g., creams, ointments)... 

Ion exchange is used to purify water. Deionized water is prepared by passing water through an anion-exchange resin in its OH- form and a cation-exchange resin in its H form. Suppose, for example, that Cu(N03)2 is present in the solution. The cation-exchange resin binds Cu2+ and replaces it with 2H+. The anion-exchange resin binds N03 and replaces it with OH-. The eluate is pure water ... 

Tire removal of NaCI from Water (deionization) is completed by passage of the cation-exchanger effluent through a bed of anion-exchange resin. 

The analytical performance of the pH nanoelectrode compares favorably with commercial glass pH electrodes when applied for pH measurements of body fluids (serum, urine) and low ionic strength water samples (rain water, tap water, deionized water) [104],... 

Element Subboiling Quartz Still, Doubly Distilled-Water Feed Doubly Distilled in Quartz, Distilled Water Feed" Deionized, Monobed, Polyethylene Apparatus, Distilled-Water Feed" Distilled Two-Stage Commercial Metal Still, City Water Feed," Recirculating Ultrapure System, Metal" Single-Pass Deionization of Tap Water" Deionization, Carbon Absorption, Deionization, Membrane Filtration ... 

Blank water, deionized water with tritium content negligible relative to analyzed samples. 

At the end of the hour, rinse the crucible with water, deionized water, and 15 mL of acetone. Allow to air dry. Add about 1 g of diatomaceous earth (Celite 545 AW, or equivalent), packing it down firmly. Dry at 130° to constant weight. Cool the cmcible for about 1 h in a desiccator, then weigh accurately. 

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