Buffer NaHCOj

Figure 4.12 — (A) Flow-cell for the simultaneous determination of four analytes (1) ion-selective electrodes (2) reference electrode (3) Pt wire for grounding (4) Teflon gasket (5) carrier (6) inlet for reference solution (7) waste (8) screws (9) diecast box (10) rubber sheet for sealing. (B) Seven-electrode holder (the reference electrode is placed from the top into die central bore). ISEs for Na, K, Ca ", NOj", Cr, and HCO, (NH, electrode with internal buffer of 0.1 mmol/L NaHCOj) are placed horizontally around the reference electrode, the metal waste tubes being connected to the waste via filter-paper strips. (Reproduced from [124] and [108] with permission of Elsevier Science Publishers and VCH Publishers, respectively).

Dichlorophenol-indophenol sodium salt (2H2O) [620-45-1 ] M 326.1, e = 2.1 x 10 at 600nm and pH 8. Dissolved in O.OOIM phosphate buffer, pH 7.5 (alternatively, about 2g of the dye was dissolved in 80ml of M HCl), and extracted into ethyl ether. The extract was washed with water, extracted with aqueous 2% NaHCOj, and the sodium salt of the dye was ppted by adding NaCl (30g/100ml of NaHCOj soln), then filtered off, washed with dilute NaCl soln and dried. 

Effect of 100 pH methylene blue dye on bubble production in agarose gels (0.2% w/w, 0.27 ml) containing distilled water and pH 4.5 (1 mM NaHCOj) buffer. (Taken from ref. 231.)... 

Flow Dialysis - Dialysis tubing is boiled in 5% NaHCOj and then in deionized water. Buffer, 10 mM HEPES-KOH, 100 mM KQ, pH 7.5, is treated for the removal of contaminating calcium by Chelex chromatography (Biorad Laboratories). EDTA is removed from protein samples by passage over two Sephadex G-25 PD-10 columns. Calcium is removed from protein samples dialyzed against HEPES-KQ buffer by Chelex chromatography just prior to flow dialysis. The concentration of calcium is determined in all solutions by atomic absorption spectrophotometry. 

Carbonate/bicarbonate buffer 0.159 g of Na2C03,0.294 g of NaHCOj. Acyust the pH to 9.6 and make up to 100 mL in disdlled water. Make up the solution freshly before each assay. 

The reaction is buffered by NaHCOj to prevent hydrolysis of the TBDMS protecting group by the acid produced in the course of the reaction. 

Hearts from CD-I male rats (250-300 g n=4 each group, 34 total) are excised and perfused within 25 s to 2 min with non-recirculating oxygenated Krebs-Henseleit bicarbonate buffer (120 mM NaCl, 25 mM NaHCOj, 1.2 mM MgSO -ZHp, 5 mM KCl, 1.7 mM CaCl-2H20, 10 mM glucose, pH 7.4, 37°C) at a constant coronary perfusion pressure (CPP) of 80 mm Hg (18, 19). 

Fully (50 mM) HEPES buffered DMEM (i.e., without NaHCOj) is prepared with DMEM from Cambrex (Cat. 15-604D) as described earlier. 

Wash beads with 100 ml 100 mM sodium phosphate buffer, pH 6.0, and then with 50 ml 100 mM NaHCOj,... 

The epoxidation of ethene-1,1 -diylbisphosphonic acid esters with 30% H2O2 in NaHCOj buffered solution yields esters of 2,2-oxiranediylbisphosphonic acid ... 

A certain buffer is made by dissolving NaHCOj and Na2C03 in some water. Write equations to show how this buffer neutralizes added and OH . 

Scheme 14.3 Total synthesis of L-696,474 (1139), starting from precursor 1124. Reagents and conditions a) trifluoroacetic acid, CH2CI2, 0°C b) [bis(trifluoroacetoxy)iodo]benzene, 2,6-lutidine, 4 A MS, CH2CI2, rt, 90% over two steps c) 1,3-diaminopropane, CF3CH2OH, Et20, it Et20-pH 7 buffer d) KOH, I2, MeOH, rt, 96% over two steps e) dimethyldioxirane, acehme, it, 95% f) Dess-Martin periodinane, NaHCOj, CH2CI2, rt g) 1135, KHMDS, THF, -78°C then 1134, -100 to -40°C, 86% over two steps h) (MeO>2POCH2Li, THF, -78°C to rt i) TBAF, AcOH, THF, rt, 81% over two steps j) Dess-Martin periodinane, NaHC03, CH2CI2, rt ...

Embryos and explants are cultured in dilutions of Normal Amphibian Medium (NAM 14) llOmM NaCl 2mM KCl ImM CalNOji ImM MgSO, 0.1 mAf Na EDTA 2mM sodium phosphate pH 7.5 ImMNaHCOj 50 Xg/mL gentamy-cin. It is convenient to prepare a lOX stock solution of all the components of NAM with the exception of the phosphate buffer, the NaHCOj, and the gentamycin. This lOX NAM salts stock may be autoclaved. We then prepare ... 

In the renal buffering process, sodium (Na+) is exchanged for hydrogen ions (H+) and binds with some of the bicarbonate (NaHCOj), which later breaks down again as Na" is actively removed through a Na - K+ mechanism (discussed in more detail in Chapter 5). The H" ions are bound with carbonic anhydrase on the border of the proximal tubules of the kidneys, which convert the H first to H COj and then to H O and CO. Some H+ ions also bind with the ammonia (NHj) produced in the kidneys as a result of amino acid catabolism and an abundant anion found in the glomerular filtrate, chloride (CT), to form ammonium chloride (NH Cl), a weak acid that is excreted in the urine. Thus it is clear that other electrolytes are involved in the acid-base balancing process and can be affected by acid-base imbalances. These impacts will be discussed with each electrolyte. 6... 

For example, the optimal binding and elution buffers for the lead ligand developed herein are 10 mM KH2PO45 pH 6.0, and 0.1 M NaHCOj, 0.1% (w/v) CHAPS, pH 10, respectively. 

For measuring the solubility of silica in water Stbber (138) adopted a standard buffered salt solution (Ringer s solution) containing 0.9% NaCI, which e.xpedites equilibration but does not affect solubility, and 0.1% NaHCOj, which buffers the solution at pH 8.4, where dis.solulion occurs most rapidly vvithoul appreciable formation of silicate ions that would occur at higher pH. 

Buffered solutions are found extensively in the body, where they serve to protect us from the disastrous effects of large deviations in pH. An important buffer system in blood is composed of carbonic acid (H2CO3) and bicarbonate salts such as NaHCOj. The unstable carbonic acid results when dissolved CO2 reacts with water in the blood ... 

The urine was adjusted to pH 4.6 with acetate buffer and incubated with p-glucuronidase-arylsufa-tase (3 mL/100 mL of fresh urine) at 37°C for 48 h, followed by continuous ether extraction for 48 h. The ether extracts were washed with 5% NaHCOj and 5% NaOH to remove the acidic and phenolic components, respectively. The ether extract was dried over MgS04, followed by evaporation of the solvent to give the neutral crude metabolites (Ishida et al., 1981). 

Alternatively the above epoxidation of a,p-unsaturated carboxylic acids can be achieved by using ozone-acetone system and buffering the reaction with NaHCOj in 75-80% yield. 

Practice Exercise How would you prepare a liter of carbonate buffer at a pH of 10.10 You are provided with carbonic acid (H2CO3), sodium hydrogen carbonate (NaHCOj), and sodium carbonate (Na2C03). See Table 16.4 for values. 

Fluorescence spectra of 52 ([52] = 1 pM) in aqueous polycation solution ([8] = 31 pM) buffered with Na2COj and NaHCOj (0.5 mM each, pH 10.2) at various ATP concentrations. The spectra are normalized at 377 nm. Excitation 342 nm. Reproduced from ref. 63 with permission from The Royal Society of Chemistry. 

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