Approx. 2 Dilute Solution

Remove the dialyzed protein solution and estimate the amount of protein recovered (see Note 14). Dilute 100 pL of the dialyzed protein solution with 900 pL of BBS. Using BBS as a blank, read the absorbance of the diluted solution at 280 nm. A 1-mg/mL solution of protein consisting mainly of immunoglobulins will have an absorbance of approx 1.4 if read in a cuvet with a 1-cm path length. Therefore,... 

The limit of accuracy of H-NMR experiments carried out in dilute solution is around 1-5%, depending on the resolution of the spectrum, and of approx. 10% for NMR. If the polymer to be investigated proved to be insoluble, solid-... 

This complex, while sensitive to oxygen and moisture, is stable for extended periods either neat or in solution. Its carbonyl stretching band (approx. 1610 cm-) in the IR spectrum in dilute solution clearly indicates a chelate structure, which endows the carbon-titanium bond of this complex with very high stability, as compared with that of simple alkyltrichlorotitaniums [25]. 

The hydrogen peroxide and water vapour leaving the lead coil and tho auxiliary distillation column combine and are introduced into the main column for fractional condensation. This first column is scrubbed with a diluted solution of hydrogen peroxide (approx. I to 2 per cent H202) obtained in the second column. The final product which contains about 35 per cent b. w. HjOj is run off from the bottom of the column and collected in the receiving tourrils. 

TEXAPRET WIi is the approx. 50% solution of a non-ionic polyether in water. It is highly viscous and has a weakly acid reaction. The solution can be diluted with cold water. When heated to temperatures above 32C, the polyether is precipitated out of the solutions, but it dissolves again on cooling. Should TEXAPRET WL precipitate and cause stains on the goods when the finishing bath is heated, these stains can be removed by treating the goods with cold water. 

The error is not appreciable, however, so long as n is small compared with N, that is, so long as the solution is dilute Hence, van t Hoffs expression will apply to a very dilute solution even though this is not strictly ideal The order of magnitude may be estimated in the following way Consider a decmormal solution in water, and as an extreme case let (Va - bt + e) — io(Vx - b ) We then have njN = 1/550 and (N + n)jN = unity approx Hence,... 

Prepare a dilute solution of HCl by the addition of 10 ml concentrated HCl to 50 ml water (approx. 2N HCl). Now, start pouring the warm hydrolysis reaction mixture into the above acidic solution in small lots at intervals with constant vigorous stirring. Allow the resulting reaction mixture to cool in an ice-bath to get the crystals of the desired product. 

Retinoic acid Transfer some crystals (or powder) (approx 2-3 mg) of all-trans retinoic acid into a volumetric flask (for example 10-mL capacity). Dissolve the solid m ethanol, and make up the volume (this is the stock solution). Pipet out 1.0 mL of the stock solution and dilute to 10.0 mL by adding 9.0 mL of ethanol. Dilute 1.0 mL of this solution to 10.0 mL. Scan the absorption spectrum from 250 to 400 nm in a UV-visible spectrophotometer. Confirm that the spectrum looks like a typical retinoic acid spectrum (see Fig. 2). Read the absorbance (optical density, OD) of the solution at the maximum (350 nm). Note If the stock solution is too concentrated (absorbance greater than 1.5 OD for many spectrophotometers), it will be necessary to dilute the solution as described. If the concentration is very low (less than 0.1 OD for many spectrophotometers), it will be necessary to read the absorbance of a less-diluted solution. 

Acetic acid, CH3COOH, (M. Wt. 60.05). To prepare approx. IM solution, dilute 57.5 ml of pure glacial acetic acid to 1 litre. Check by titration with alkali against phenolph-thalein. Acetic acid/sodium acetate buffers are prepared by partial neutralization of acetic acid solutions with NaOH NaOAc should not be used. 

Procedure A with standard hydrochloric acid. Place the standardised (approx. 0.1 M) hydrochloric acid in the burette. Transfer 25 mL of the sodium hydroxide solution into a 250 mL conical flask with the aid of a pipette, dilute with a little water, add 1-2 drops of methyl orange or 3-4 drops of methyl orange-indigo carmine indicator, and titrate with the previously standardised hydrochloric acid. Repeat the titrations until duplicate determinations agree within 0.05 mL of each other. 

Pipette 25 mL of the bismuth solution (approx. 0.01 M) into a 500 mL conical flask and dilute with de-ionised water to about 150 mL. If necessary, adjust the pH to about 1 by the cautious addition of dilute aqueous ammonia or of dilute nitric acid use a pH meter. Add 30 mg of the xylenol orange/potassium nitrate mixture (see Section 10.50) and then titrate with standard 0.01 M EDTA solution until the red colour starts to fade. From this point add the titrant slowly until the end point is reached and the indicator changes to yellow. 

Pipette 25 mL of the solution containing magnesium, manganese and zinc ions (each approx. 0.02M), into a 250 mL conical flask and dilute to 100 mL with de-ionised water. Add 0.25 g hydroxylammonium chloride [this is to prevent oxidation of Mn(II) ions], followed by 10 mL of the buffer solution and 30-40 mg of the indicator/potassium nitrate mixture. Warm to 40 °C and titrate (preferably stirring magnetically) with the standard EDTA solution to a pure blue colour. 

Procedure. Place 10 mL of the solution containing the two metals (the concentration of neither of which should exceed 0.01 M) in a 600mL beaker fitted with a magnetic stirrer, and dilute to 100 mL with de-ionised water. Add 20 mL of standard (approx. 0.01 M) EDTA solution and add hexamine to adjust the pH to 5-6. Then add a few drops of the indicator solution (0.5 g xylenol orange dissolved in 100 mL of water) and titrate the excess EDTA with a standard lead nitrate solution (0.01 M), i.e. to the formation of a red-violet colour. 

Pipette 25.0 mL of the phosphate solution (approx. 0.05M) into a 250 mL beaker and dilute to 50 mL with de-ionised water add 1 mL of concentrated hydrochloric and a few drops of methyl red indicator. Treat with an excess of 1M magnesium sulphate solution (ca 2mL), heat the solution to boiling, and add concentrated ammonia solution dropwise and with vigorous stirring until the indicator turns yellow, followed by a further 2 mL. Allow to stand for several... 

Luminol stock solution (approx. 20 mg luminol in 1 liter of 10 mM NaOH, to give an A value of 0.80 at 347 nm). Working solution dilute the stock solution 10 times with pH 11.6 buffer (3 g of Na2HP04 7H2O and 15 g of Na3P04 I2H2O in 1 liter of water). 

When high-resolution NMR spectra have to be recorded of a polymeric sample, one has to recognize that polymer solutions are in general highly viscous. To prevent excessive signal broadening caused by this restricted mobility of the solution, polymer solutions for NMR studies have to be highly diluted (approx. 

Dilute the DAB concentrate (10X stock) with stable peroxide buffer to IX following the manufacturer s protocol. Submerse the membrane in the DAB solution and develop for approx 3 min (Fig. 1). Rinse membrane with H20, incubate in a dark place until it is completely dry, and scan the image using a flatbed scanner. 

Prepare a 2-pg/mL solution of ribosomal RNA standard provided in TE. Prepare a series of standard RNA concentrations from 0 to 2 pg/mL. Mix equal volumes (100 pL) of diluted RiboGreen Reagent and standard RNAs. Measure the sample fluorescence using a TD-700 fluorometer (excitation approx 480 nm, emission approx 520 nm) and prepare the standard curve. 

The diluted gas obtained is led through ice-cold water, in which the chlorine monoxide will dissolve, and an approx. 10 to 15 per cent solution of hypochlorous acid will be formed ... 

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