Acid Phthalate Buffer

The oxidation of ascorbic acid at a platinum electrode in potassium acid phthalate buffer (pH 6) has been reported at +1.09 V vs. SCE [16]. Under these... 

Acid Phosphatase Activity, 788, 789 Acid Phthalate Buffer, 848 Acid Value (Essential Oils and Flavors), 815, (Sl)168, (S 1)106 Acid Value (Fats and Related Substances), 820... 

After washing with. 5 M HBr twice, the In is back-extracted into 6 g HC1. The HC1 iB evaporated to 1 ml and the pH adjusted to 2.-3 by addition of NaOH. Potassium acid phthalate buffer (pH 2,k) is then added to bring the soln. volume to 20 ml. 

Aspirin can be separated from salicylic acid by ionophoresis at a pH of 4-5.1 8 Separation of aspirin in combination products has been achieved with paper strip electrophoresis, using buffers at pH 2-8 and a 200 V. applied potential.11 9 Aspirin was separated from metabolites by paper electrophoresis in a phthalate buffer of pH 3.2 and an ionic strength of 0.0125-0.0500.150... 

Acid Buffer Buffer Phthalate Buffer Buffer Borate Buffer ... 

Buffer pH 2.2 to 3.8 this corresponds to the phthalic acid/potassium hydrogen phthalate buffer... 

The potassium hydrogen phthalate salt is the weak acid of the potassium hydrogen phthalate/dipotassium phthalate buffer which has pH range 4.0 to 6.2. 

Hamer WJ, Pinching GD and Acree SF, First dissociation constant of o-phthalic acid and related pH values of phthalate buffers from 0 to 60 , /. Res. Nat. Bur. Stand., 35, 539-564 (1945) Hamer WJ and Acree SF, /. Res. Nat. Bur. Stand., 35,381-416 (1945). NB Used electrochemical cell wiBiout liquid junction potentials detailed procedures were required to extrapolate ionic strengBi effects to zero. 

Acid Eluent Phthalate buffer Gluconate/ Hydroxide Benzoate... 

Similar results were observed when the reaction was carried out at OO C. Simitar results were obtained when vapors were permitted to distill out. When sodium acetate was used as buffer, the final reaction solution had a pH of 5.7 when sodium acid phthalate was used the final pH was 4.3. 

A colorimetric method for the estimation of one or more species of penicillin in a mixture was described by Baker, Dobson and Martin. It is based on the fact that the relatively stable hydroxamic acid derivatives of the various penicillins show different partition coefficients between w opropyl ether-/AY>propyl alcohol and phthalate buffer, at a given pH, and can therefore be separated by paper chromatography. 

Pipette 25.00 ml of standard 0.01000 N hydrochloric acid into a dry 200-ml polyethylene wide-mouth screw-cap bottle. Add from a pipette 100.0 ml of seawater sample. Stopper the bottle and mix the solutions thoroughly. Warm the solution to room temperature and measure the pH exactly as described in the preceding method, except that the phthalate buffer is used to standardize the pH meter, instead of the phosphate buffer. The pH of the phthalate buffer between 20 and 25 C is taken as 4.00. 

In weakly acidic electrolyte (phthalate buffer, pH 5.5), both alloys form pure thin (0.2-0.5nm) Sn oxide layers in the active range at E = 0.3 V. Within the passive range, Cu is... 

Procedure. To 10 mL of a solution (Note 2) containing from 1 to 10 pg of nickel(II) add 5mL of a phthalate or acetate (ethanoate) buffer of pH 6.0 or, if the sample solution is acidic, use dilute ammonia to adjust the pH. To this solution now add 15mL of a chloroform solution of dithizone (7 x 10-5M) and 1,10-phenanthroline (3 x 10-5M). Shake the phases for five minutes in a... 

A review by Galli et al. describes several buffer-absorbing chromophores as co-ions. These include phthalate, PDG (2,6-pyridinedicarboxylic acid), PMA (1,2,4,5-benzenetetra-carboxylic acid or pyromellitic acid), TMA (trimellitic acid), MES, 2,4-dihydrobenzoic acid with s-aminocaproic acid, p-hydroxybenzoate, p-anisate, 3,5-dinitrobenzoic acid, salicylic acid with TRIS, benzoic acid with tris (hydroxymethyl)aminomethane (TRIS), and many others. On the other hand, some inorganic chromophores such as chromate (Figure 9) or molybdate may be added to a buffer. A BGE-containing chromate should have a pH above 8, because it precipitates below this value. The advantage of a TRIS buffer or buffers at around pH 6 is that carbonate will not interfere with the separation because it is not soluble in TRIS or at lower pHs. 

Potassium hydrogen phthalate has many uses in analytical chemistry. It is a primary standard for standardization of bases in aqueous solutions. Its equivalent weight is 204.2. It also is a primary standard for acids in anhydrous acetic acid. Other applications are as a buffer in pH determinations and as a reference standard for chemical oxygen demand (COD). The theoretical COD of a Img/L potassium hydrogen phthalate is 1.176mg O2. 

Hartridge and Peters (Froo. Roy. Soc. A, Cl. 348, 1922) have measured the interfacial tension of liquid fatty acids and their solutions in benzene against aqueous borate, phthalate and phosphate buffer solutions of varying concentration and Ph. 

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