Standards for pH measurements in isotonic saline media of ionic strength I = 0.16

Bates, Roger G.; Vega, Carmen A.; White, Dawn

doi:10.1021/ac50031a026

Cited by 71 publications

(56 citation statements)

References 17 publications

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“…The method of Bates [5,10] has been used to evaluate the conventional standard pH values for buffer solutions (a) to (h) as was done previously [12,13,14] where the symbols "s," "l," and "g" imply the solid, liquid, and gaseous states.…”

Section: Methods and Resultsmentioning

confidence: 99%

“…To calculate the pH values for all buffer solutions under investigation, calculations were made to determine the acidity function, denoted as p(a H  Cl ), in the temperature range (278.15 to 328.15) K. These calculations [10][11][12][13][16][17][18] were made using the emf (E) values listed in Tables 1 and 2, the molality of the chloride ion, and the standard electrode potential of the silver-silver chloride electrode (E°). The equation to calculate the quantity p(a H  Cl ) is shown below:…”

Section: Methods and Resultsmentioning

confidence: 99%

“…After recrystallization two times from 75% ethanol, an assay of 99.96% with a standard deviation of 0.04% was obtained by titration of BICINE with the standard NaOH solution. The detailed procedure has been previously reported in the literature [10]. Buffer solutions from (a) to (h), as mentioned above, were prepared from mass methods by weighing solid BICINE buffer, ACS reagent grade and recrystallized NaCl, a standard NaOH solution (for the preparation of NaBICINE), and carefully calculated amounts of double distilled CO 2 -free water.…”

Section: Methodsmentioning

confidence: 99%

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Standards for pH Measurements of Bis-[(2-Hydroxyethyl)amino]acetic Acid (BICINE) from (278.15 to 328.15) K

Roy¹,

Roy²,

Bodendorfer³

et al. 2013

TOELECJ

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Abstract:The second dissociation constant, pK 2 , and related thermodynamic data for BICINE have been previously determined and reported from temperatures (278.15 to 328.15) K. For the present study, three buffer solutions without NaCl, and five with NaCl yielding an ionic strength (I = 0.16 mol·kg -1 ) similar to that of blood plasma were prepared. These buffer solutions have been evaluated in the temperature range of (278.15 to 328.15) K using the extended form of the Debye-Hückel equation. The Bates-Guggenheim convention is only valid when I< 0.1 mol·kg -1 . Values of the residual liquid junction potential (δE j ) between the BICINE solutions and the saturated KCl calomel electrode have been estimated at (298.15 and 310.15) K. Two BICINE buffer solutions are recommended as primary standard reference solutions for pH measurements of biological fluids.

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Section: Methods and Resultsmentioning

confidence: 99%

Section: Methods and Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Standards for pH Measurements of Bis-[(2-Hydroxyethyl)amino]acetic Acid (BICINE) from (278.15 to 328.15) K

Roy¹,

Roy²,

Bodendorfer³

et al. 2013

TOELECJ

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show abstract

“…Vacuum corrections were made for all masses. The cell design, preparation of the chloroplatinic acid, hydrogen gas purification, silver-silver chloride, solution preparation, and other experimental details have been described previously [10][11][12][13].…”

Section: Methodsmentioning

confidence: 99%

Buffer Standards for the Biochemical pH of the Zwitterionic Buffer <i>N</i>-Tris-(Hydroxymethyl) Methyl-2-Aminoethanesulfonic Acid (TES) from 5℃ to 55℃

Roy¹,

Roy²,

Bodendorfer³

et al. 2012

OJPC

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The authors have undertaken the determination of pH values for one buffer solution of TES without NaCl and nine buffer solutions with NaCl yielding an ionic strength I = 0.16 mol·kg -1 similar to that of blood. These buffer solutions have been evaluated in the temperature range of 5˚C to 55˚C using an extended version of the Debye-Hückel equation.The pH values are reported using 1) the Debye-Hückel extension of the Bates-Guggenheim convention in the temperature range 5˚C to 55˚C and 2) with and without liquid junction correction at 25˚C and 37˚C. These TES buffer solutions are recommended as secondary standard references for pH measurements in the range of pH 7.2 to 7.5 for physiological application with an ionic strength of I = 0.16 mol·kg -1 .

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“…Thermodynamic pKa data (I = 0) are available for buffers commonly used in biorelevant dissolution media (see Table 2) (21-32); however, these values do not reflect the electrolyte environment where buffer concentration is relatively low and salts, such as sodium chloride, contribute significantly to the ionic strength of the media. For example, the thermodynamic pKa 2 for a phosphate buffer system at 37 °C is 7.181 (Table 2) (21-32) while pKa 2 ' is 6.75 at 37 °C under conditions where the buffer concentration is low and sodium chloride contributes significantly to the ionic strength of the buffer solution (33). Selecting a pKa' value measured at a temperature close to test conditions is another factor because pKa-temperature dependence for buffers such as TRIS may be significant (34).…”

Section: Relationship Between the Target Dissolution Media Ph And Bufmentioning

confidence: 99%

Physicochemical Properties of Buffers Used in Simulated Biological Fluids with Potential Application for In Vitro Dissolution Testing: A Mini-review

Mauger¹

2017

Dissolution Technol.

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Although aqueous buffers alone cannot be expected to fulfill all the requirements of biorelevant media, buffers will likely continue to play a central role in controlling the pH of complex formulations simulating biological fluids (3,9). The use of biorelevant dissolution media to forecast in vivo drug performance has been reviewed (9). This minireview focuses on the physicochemical factors related to buffers used in these media and not the biorelevant dissolution media, per se. This mini-review is based on a survey of the literature associated with buffers in general ABSTRACTThis literature review focuses on the physicochemical properties of buffers used in biorelevant media for in vitro dissolution testing. Because biorelevant dissolution systems have been previously reviewed, this review is primarily related to the buffers used in biorelevant media and not the media, per se. It is based on a survey of the literature in areas including analytical chemistry; biochemistry; clinical, solution, and physical chemistry; dissolution science and technology; pharmaceutical sciences; simulated biological fluids; and buffer-related articles from the National Institute of Standards and Technology with the intent of identifying challenges in formulating buffered biorelevant dissolution media and also identifying general attributes that are useful in selecting a buffer for a particular dissolution application. Other topics include: (1) key physicochemical properties of buffers that affect experimental conditions and dissolution results; (2) buffer compatibility with a diverse array of ingredients found in biorelevant media; and (3) the potential to supplement the library of traditional buffers used for in vitro dissolution testing with zwitterionic buffers that were designed for biological application.

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Standards for pH measurements in isotonic saline media of ionic strength I = 0.16

Cited by 71 publications

References 17 publications

Standards for pH Measurements of Bis-[(2-Hydroxyethyl)amino]acetic Acid (BICINE) from (278.15 to 328.15) K

Standards for pH Measurements of Bis-[(2-Hydroxyethyl)amino]acetic Acid (BICINE) from (278.15 to 328.15) K

Buffer Standards for the Biochemical pH of the Zwitterionic Buffer <i>N</i>-Tris-(Hydroxymethyl) Methyl-2-Aminoethanesulfonic Acid (TES) from 5℃ to 55℃

Physicochemical Properties of Buffers Used in Simulated Biological Fluids with Potential Application for In Vitro Dissolution Testing: A Mini-review

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Standards for pH measurements in isotonic saline media of ionic strength I = 0.16

Cited by 71 publications

References 17 publications

Standards for pH Measurements of Bis-[(2-Hydroxyethyl)amino]acetic Acid (BICINE) from (278.15 to 328.15) K

Standards for pH Measurements of Bis-[(2-Hydroxyethyl)amino]acetic Acid (BICINE) from (278.15 to 328.15) K

Buffer Standards for the Biochemical pH of the Zwitterionic Buffer &lt;i&gt;N&lt;/i&gt;-Tris-(Hydroxymethyl) Methyl-2-Aminoethanesulfonic Acid (TES) from 5℃ to 55℃

Physicochemical Properties of Buffers Used in Simulated Biological Fluids with Potential Application for In Vitro Dissolution Testing: A Mini-review

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Buffer Standards for the Biochemical pH of the Zwitterionic Buffer <i>N</i>-Tris-(Hydroxymethyl) Methyl-2-Aminoethanesulfonic Acid (TES) from 5℃ to 55℃