Borate pH buffer

Hgure 6 Effect of deposition potential on reduction peak signal for the determination of Zn using ACSV in deionized water. Conditions 0.01 mmol 1 APDC and 0.01 mol 1" borate (pH buffer) with a deposition time of 60s in the presence of lOnmoir added Zn. 

Borate pH buffer. A solution is prepared containing 1 mol/L boric acid and 0.35 mol/L ammonia. This buffer gives a pH of 8.35 when diluted 100-fold in seawater. Boric acid may precipitate if the pH of this solution is too low, in which case the ammonia concentration has to be increased. Contaminating metal ions can be removed from this buffer by adsorption on Mn02 which is removed by filtration. Thereto Mn02 suspension is added to a final concentration of 50-100//mol/L the mixture is equilibrated for several hours and then filtered over a 0.45 pm filter. 

Fig.12-12. Slow increase of the peak for labile copper in seawater from the eastern Atlantic due to the gradual release of copper from or nk complexes. Conditirms 25pmol/L oxine, borate pH buffer (pH 8.3), 90s adsorption at -0.15 V, scans initiated from -0.15 V. Data from the author (unpublished Challenger cruise, March 1991).

This experiment describes a quantitative analysis for caffeine, theobromine, and theophylline in tea, pain killers, and cocoa. Separations are accomplished by MEKC using a pH 8.25 borate-phosphate buffer with added SDS. A UV detector set to 214 nm is used to record the electropherogram. An internal standard of phenobarbital is included for quantitative work. 

Use of 10 pm LiChrosorb RP18 column and binary eluent of methanol and aqueous 0.1 M phosphate buffer (pH 4.0) according to suitable gradient elution program in less than 20-min run time with satisfactory precision sensitivity of spectrophotometric detection optimized, achieving for all additives considered detection limits ranging from 0.1 to 3.0 mg/1, below maximum permitted levels Simultaneous separation (20 min) of 14 synthetic colors using uncoated fused silica capillary column operated at 25 kV and elution with 18% acetonitrile and 82% 0.05 M sodium deoxycholate in borate-phosphate buffer (pH 7.8), recovery of all colors better than 82%... 

Figure 11 Separation of anti-inflammatories by CZE at various pHs in a 40-cm polyacrylamide-coated (left) and a 70-cm uncoated (right) capillary Experimental conditions 275 V/cm UV = 215 nm buffers 20 mM borate-100 mM boric acid, pH 8.4 (46 pA) 30 mM phosphate-9 mM borate, pH 7.0 (70 pA) 80 mM MES-30 mM Tris, pH 6.1 (20 pA) peak identification 1 = naproxen, 2 = ibuprofen, 3 = tolmetin. (From Wainwright, A., /. Microcol Sep., 2, 166, 1990. With permission.)...

Lin et al. [95] used capillary electrophoresis with dual cyclodextrin systems for the enantiomer separation of miconazole. A cyclodextrin-modified micellar capillary electrophoretic method was developed using mixture of /i-cyclodextrins and mono-3-0-phenylcarbamoyl-/j-cyclodextrin as chiral additives for the chiral separation of miconazole with the dual cyclodextrins systems. The enantiomers were resolved using a running buffer of 50 mmol/L borate pH 9.5 containing 15 mmol/L jS-cyclodextrin and 15 mmol/L mono-3-<9-phcnylcarbamoyl-/j-cyclodextrin containing 50 mmol/L sodium dodecyl sulfate and 1 mol/L urea. A study of the respective influence of the /i-cyclodcxtrin and the mono-3-(9-phenylcarbamoyl-/i-cyclodextrin concentration was performed to determine the optical conditions with respect to the resolution. Good repeatability of the method was obtained. 

The amidine bond formed is quite stable at acid pH however, it is susceptible to hydrolysis and cleavage at high pH. A typical reaction condition for using imidate crosslinkers is a buffer system consisting of 0.2 M triethanolamine in 0.1 M sodium borate, pH 8.2. After conjugating two proteins with a bifunctional imidoester crosslinker, excess imidoester functional groups may be blocked with ethanolamine. 

Dissolve the amine-dendrimer to be modified in DMF or buffer (50mM sodium borate, pH 8.5) at a concentration of at least lOmg/ml. Avoid the use of amine-containing buffers for an aqueous reaction, such as Tris or imidazole, as these will react with the... 

Prepare a carboxylated QD solution in lOmM sodium borate, pH 7.4 (reaction buffer), at a concentration of 1 pM. The supplier of QDs usually will provide the reagent concentration as a molar quantity, which treats each particle as though it was a single molecule. A typical QD solution as obtained from a manufacturer may be about 8 pM starting concentration. 

Dissolve (strept)avidin) in 50mM sodium borate, pH 8.5, at a concentration of lOmg/ml. Other buffers may be used for an NHS ester reaction, including 0.1M sodium phosphate, pH 7.5 (Chapter 2, Section 1.4). 

Dissolve the protein to be modified with TsT-mPEG in ice-cold 0.1 sodium borate, pH 9.4, at a concentration of 2-10 mg/ml. Other buffers at lower pH values (down to pH 7.2) can be used and still obtain modification, but the yield will be less. Avoid amine-containing buffers such as Tris or the presence of sulfhydryl-containing compounds, such as disulfide reductants. 

Figure 10 Separation of ABEI-DSC-derivatized n-octylamine (2) and n-propylamine (3) with ECL detection. Remaining ABEI (1) and ABEI DSC (not shown) are also detected. Conditions 20% methanol in 5 mM sodium borate separation buffer, pH 10.9 5-s injection at 25 kV, 1.0 X 10 6 for each labeled amine 25-kV separation potential 10-mm platinum wire electrode. (From Ref. 85, with permission.)...

Figure 13 Electropherogram of selected amino acids with end-column addition of 1 mM Ru (bpy)32+. Separation conditions 20 kV with injection of analytes for 8 s at 20 kV. Capillary, 75 im id, 62 cm long with a 4-cm detection capillary. Buffer 15 mM borate, pH 9.5. The electrode used for in situ generation of Ru(bpy)33+ was a 35-jlm-diameter carbon fiber, 3 mm long held at 1.15 V versus a saturated calomel electrode. The PMT was biased at 900 V. Peak identification (1) 100 fmol TEA, (2) 70 fmol proline (3) 1.6 pmol valine, (4) 50 pmol serine. Injection points. (From Ref. 97, with permission.)...

Fig. 17.11. Bottom CGE separation of components of poly U (sigma) in 25% pluronic F127. Top Note the resolution of two contaminants between each of the oligonucleotides from about 15 to 27 nucleotides long in this expanded section of the bottom electropherogram. Electrophoresis was performed in 25% pluronic F127 in tris-borate-EDTA buffer (90 mM tris, 90 mM boric acid, 2 mM Na EDTA, pH 8.3.) (25°C, 500 V cm-1, effective column length 30 cm). Reprinted with permission from Ref. [82],...

Other buffers that have been used for continuous, native electrophoresis are Tris-glycine (pH range 8.3 to 9.5),19 Tris-borate (pH range 8.3 to 9.3),26 and Tris-acetate (pH range 7.2 to 8.5).27 Borate ions26 can form complexes with some sugars and can therefore influence resolution of some glycoproteins. 

M Borate-NaCl buffer 76.3 g sodium borate 10 H2O and 9 g sodium chloride bring volume to 1 L with deionized glass-distilled water, pH 9.0. 

Dialyze the antibody For monoclonal antibodies, etc., already diluted with 0.2 M borate-NaCl buffer, dialyze against 2 mM borate-NaCl buffer, pH 9.0 for 2 h for all other antibodies, first dialyze overnight against 0.2 M borate buffer-NaCl, pH 9.0, and then for 2 h against 2 mM borate buffer, pH 9.0. Do not leave the antibodies in the 2 mM borate buffer for extended periods or the antibodies may aggregate. 

Figure 13.9 Microchip-based micellar electrokinetic chromatography (MEKC) electro-pherogram of a mixture of nitroaromatics and nitramines. Analytes 20 ppm of each (1) TNB, (2) DNB, (3) NB, (4) TNT, (5) tetryl, (6) 2,4-DNT, (7) 2,6-DNT, (8) 2-, 3-, and 4-NT, (9) 2-Am-4,6-DNT, (10) 4-Am-2,6-DNT. Conditions MEKC buffer, 50 mM borate, pH 8.5, 50 mM SDS, 5 M Cy7, separation voltage 4 kV, separation distance 65 mm. (Reprinted in part with permission from [37]. Copyright 2000 American Chemical Society.)...

Cold medicine ingredients 1.66 SDS, 0.81% heptane, 6.61% butane-l-ol, borate-phosphate buffer, pH 7 9, 27... 

Gel Electrophoresis This method was used in the determination of the purity of native lysozyme and identification of ozonized products. Different gel concentrations (7,8,9,10%) and buffer solutions (0.25M borate, pH 8.7 0.025M phosphate, pH 7.1) were tried and the best results were obtained with 7% gel in pH 8.7 buffer. 

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