Publications (97)193.16 Total impact
 Open Journal of Physical Chemistry 01/2014; 04(02):7379. DOI:10.4236/ojpc.2014.42011
 Journal of Biophysical Chemistry 01/2014; 05(04):143151. DOI:10.4236/jbpc.2014.54016
 Journal of Biophysical Chemistry 01/2014; 05(03):118124. DOI:10.4236/jbpc.2014.53013
 Journal of Biophysical Chemistry 01/2014; 05(03):9198. DOI:10.4236/jbpc.2014.53010
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ABSTRACT: The pH values of two buffer solutions without NaCl and seven buffer solutions with added NaCl, having ionic strengths (I = 0.16 mol·kg(1)) similar to those of physiological fluids, have been evaluated at 12 temperatures from T = (278.15 to 328.15) K by way of the extended form of the DebyeHückel equation of the BatesGuggenheim convention. The residual liquid junction potentials (δE(j)) between the buffer solutions of TRICINE and saturated KCl solution of the calomel electrode at T = (298.15 and 310.15) K have been estimated by measurement with a flowing junction cell. For the buffer solutions with the molality of TRICINE (m(1)) = 0.06 mol·kg(1), NaTRICINE (m(2)) = 0.02 mol·kg(1), and NaCl (m(3)) = 0.14 mol·kg(1), the pH values at 310.15 K obtained from the extended DebyeHückel equation and the inclusion of the liquid junction correction are 7.342 and 7.342, respectively. These are in excellent agreement. The zwitterionic buffer TRICINE is recommended as a secondary pH standard in the region for clinical application.The Journal of Chemical Thermodynamics 09/2012; 52:1115. DOI:10.1016/j.jct.2012.02.019 · 2.42 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: In this study, we report the pH values of two buffer solutions without chloride ion and eight buffer solutions with NaCl with an ionic strength I=0.16 mol⋅kg−1. Electromotive force (emf) techniques have been used to get the cell potentials at 12 temperatures from 5 to 55 °C, including 37 °C. An extended form of the BatesGuggenheim convention is used in the entire ionic strength range, 0.04 to 0.16 mol⋅kg−1. The residual liquid junction potentials (δE j ) of the buffer solutions of MOBS have been estimated from previous measurements with a flowing junction cell. These values of δE j have been used for correction in order to ascertain the operational pH values of four buffer solutions of MOBS at 25 and 37 °C. These solutions are recommended as pH standards for physiological application in the pH range 7.4 to 7.7.Journal of Solution Chemistry 07/2012; 41(6). DOI:10.1007/s109530129847y · 1.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: This paper reports the pH values of five NaClfree buffer solutions and eleven buffer compositions containing NaCl at I = 0.16 mol·kg(1). Conventional pa(H) values are reported for sixteen buffer solutions with and without NaCl salt. The operational pH values have been calculated for five buffer solutions and are recommended as pH standards at T = (298.15 and 310.15) K after correcting the liquid junction potentials. For buffer solutions with the composition m(1) = 0.04 mol·kg(1), m(2) = 0.08 mol·kg(1), m(3) = 0.08 mol·kg(1) at I = 0.16 mol·kg(1), the pH at 310.15 K is 7.269, which is close to 7.407, the pH of blood serum. It is recommended as a pH standard for biological specimens.The Journal of Chemical Thermodynamics 04/2012; 47:2127. DOI:10.1016/j.jct.2011.09.010 · 2.42 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: This paper reports the results for the pH of six buffer solutions free of chloride ion with compositions: (a) BES (0.03 mol·kg(1)) + NaBES (0.09 mol·kg(1)); (b) BES (0.02 mol·kg(1)) + NaBES (0.04 mol·kg(1)); (c) BES (0.04 mol·kg(1)) + NaBES (0.08 mol·kg(1)); (d) BES (0.04 mol·kg(1)) + NaBES (0.04 mol·kg(1)) (e) BES (0.05 mol·kg(1)) + NaBES (0.05 mol·kg(1)); and (f) (0.06 mol·kg(1)) + NaBES (0.06 mol·kg(1)). The remaining eight buffer solutions (g) to (n) have saline media of the ionic strength I = 0.16 mol·kg(1), matching closely to that of the physiological sample. Conventional pa(H) values, designated as pH(s), for all six buffer solutions (a)  (f) without the chloride ion and eight buffer solutions with the chloride ion (g)  (n) at I = 0.16 mol·kg(1) from (278.15 K to 328.15) K have been calculated. The operational pH values for five buffer solutions at T = 298.15 K and T = 310.15 K have been determined based on the difference in the values of the liquid junction potentials between the blood phosphate standard and the experimental buffer solutions. Five of these buffers are recommended as secondary standards for the physiological pH range 7.5 to 8.5.Journal of electroanalytical chemistry 12/2011; 663(1):813. DOI:10.1016/j.jelechem.2011.09.019 · 2.87 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: For the HEPPS buffer under investigation, there are seven buffer solutions without NaCl and eight buffer solutions that contain Cl() and have an ionic strength (I = 0.16 mol·kg(1)), which is similar to that of blood plasma. These buffer solutions have been evaluated in the temperature range of (278.15 to 328.15) K using the extended Debye Hückel equation and the BatesGuggenheim convention. The previously determined E(j) values have been used to determine the operational pH values of HEPPS buffer solutions at (298.15 and 310.15) K. These are recommended as secondary standard reference solutions for pH measurements in saline media with an isotonic ionic strength of I = 0.16 mol·kg(1).Journal of Chemical & Engineering Data 11/2011; 56(11):41264132. DOI:10.1021/je200629y · 2.05 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: The values of the second dissociation constant pK2 and related thermodynamic quantities of the ampholyte 3[4(2hydroxyethyl)1piperazinyl]propanesulfonic acid (HEPPS) have already been published at temperatures from T = (278.15 to 328.15) K. The pH values of two equimolal buffer solutions and eight buffer solutions with ionic strengths similar to that of plasma in blood (I = 0.16 mol·kg−1) have been experimentally determined and then corrected at 12 temperatures from T = (278.15 to 328.15) K using the extended Debye−Hückel equation. The liquid junction potentials (Ej) between the buffer solutions of HEPPS and the saturated KCl solution of the calomel electrode at (298.15 and 310.15) K have been estimated by measurement with the flowing junction cell. These values of Ej have been used to ascertain the operational pH values at T = (298.15 and 310.15) K. The zwitterionic buffer HEPPS was proven to be useful through experimentation as a pH standard well within the region close to blood serum.Journal of Chemical & Engineering Data 11/2009; 55(3). DOI:10.1021/je9006508 · 2.05 Impact Factor 
Article: Buffer Standards for the Physiological pH of the Zwitterionic Compound, HEPPSO from 5 to 55 °C
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ABSTRACT: The values of the thermodynamic second dissociation constant, pK 2, and related thermodynamic quantities of N(2hydroxyethyl)piperazineN′2hydroxypropanesulfonic acid (HEPPSO) have already been reported from 5 to 55 °C, including 37 °C, by the emf method. This paper reports the results for the pH of one chloridefree buffer solution containing the composition: (a)HEPPSO (0.08mol⋅kg−1)+NaHEPPSO(0.04mol⋅kg−1). The remaining seventeen buffer solutions contain a saline medium of ionic strength I=0.16mol⋅kg−1, matching closely that of physiological fluids. Conventional pH values, denoted as pa H, for all eighteen buffer solutions from 5 to 55 °C have been calculated. The operational pH values, designated as pH, with residual liquidjunction corrections for five buffer solutions, one without NaCl, and four with buffer solutions in saline media of I=0.16mol⋅kg−1 are recommended as pH standards in the range of physiological application. These are based on the NBS/NIST standard scale for pH measurements.Journal of Solution Chemistry 11/2009; 38(11):14171431. DOI:10.1007/s109530099442z · 1.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: The values of the second dissociation constant pK(2) and related thermodynamic quantities of the ampholyte 3(Nmorpholino)2hydroxypropanesulfonic acid (MOPSO) have been previously determined at temperatures from (278.15 to 328.15) K. In this study, the pH values of two buffer solutions without NaCl and three buffer solutions with NaCl having ionic strengths (I = 0.16 mol·kg(1)) similar to those in blood plasma, have been evaluated at 12 temperatures from (278.15 to 328.15) K using an extended form of the DebyeHückel equation, since the BatesGuggenheim convention is valid up to I = 0.1 mol·kg(1). The liquid junction potentials (E(j)) between the buffer solutions of MOPSO and saturated KCl solution of the calomel electrode at (298.15 and 310.15) K have been estimated by measurement with a flowing junction cell. These values of E(j) have been used to ascertain the operational pH values at (298.15 and 310.15) K. Three buffer solutions of MOPSO are recommended as useful reference solutions for pH measurements in saline media of ionic strength I = 0.16 mol·kg(1).Journal of Chemical & Engineering Data 06/2009; 54(6):18601864. DOI:10.1021/je800983y · 2.05 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: The values of the second dissociation constant, pK(2) of N(2hydroxyethyl) piperazineN'2ethanesulfonic acid (HEPES) have been reported at 12 temperatures over the temperature range 5 to 55 degrees C, including 37 degrees C. This paper reports the results for the pa(H) of eight isotonic saline buffer solutions with an I = 0.16 mol*kg(1) including compositions: (a) HEPES (0.01 mol*kg(1)) + NaHEPES (0.01 mol*kg(1)) + NaCl (0.15 mol*kg(1)); (b) HEPES (0.02 mol*kg(1)) + NaHEPES (0.02 mol*kg(1)) + NaCl (0.14 mol*kg(1)); (c) HEPES (0.03 mol*kg(1)) + NaHEPES (0.03 mol*kg(1)) + NaCl (0.13 mol*kg(1)); (d) HEPES (0.04 mol*kg(1)) + NaHEPES (0.04 mol*kg(1)) + NaCl (0.12 mol*kg(1)); (e) HEPES (0.05 mol*kg(1)) + NaHEPES (0.05 mol*kg(1)) + NaCl (0.11 mol*kg(1)); (f) HEPES (0.06 mol*kg(1)) + NaHEPES (0.06 mol*kg(1)) + NaCl (0.10 mol*kg(1)); (g) HEPES (0.07 mol*kg(1)) + NaHEPES (0.07 mol*kg(1)) + NaCl (0.09 mol*kg(1)); and (h) HEPES (0.08 mol*kg(1)) + NaHEPES (0.08 mol*kg(1)) + NaCl (0.08 mol*kg(1)). Conventional pa(H) values, for all eight buffer solutions from 5 to 55 degrees C have been calculated. The operational pH values with liquid junction corrections, at 25 and 37 degrees C have been determined based on the NBS/NIST standard between the physiological phosphate standard and four buffer solutions. These are recommended as pH standards for physiological fluids in the range of pH 7.3 to 7.5 at I = 0.16 mol*kg(1).Journal of Solution Chemistry 04/2009; 38(4):449458. DOI:10.1007/s1095300993783 · 1.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: The values of the second dissociation constant, pK(2), and related thermodynamic quantities of 3[N,Nbis (2hydroxyethyl)amino]2hydroxypropanesulfonic acid (DIPSO) have already been reported over the temperature range 5 to 55 degrees C including 37 degrees C. This paper reports the pH values of four NaClfree buffer solutions and four buffer composition containing NaCl salt at I = 0.16 mol.kg(1). Conventional pa(H) values are reported for all eight buffer solutions. The operational pH values have been calculated for four buffer solutions recommended as pH standards, at 25 and 37 degrees C after correcting the liquid junction potentials with the flowing junction cell.Journal of Solution Chemistry 04/2009; 38(4):459469. DOI:10.1007/s1095300993792 · 1.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: The values of the second dissociation constant pK(2) and related thermodynamic quantities of [N(2acetamido)2aminoethanesulfonic acid] (ACES) have already been reported over the temperature range 5 to 55 degrees C including 37 degrees C. This paper reports the pa(H) values of four chloride ion free buffer solutions and eight buffer solutions with I = 0.16 mol.kg (1), matching closely to that of the physiological sample. Conventional pa(H) values for all twelve buffer solutions from 5 to 55 degrees C, are reported. The residual liquid junction potential correction for two widely used temperatures, 25 and 37 degrees C, has been made. The flowingjunction calomel cell method has been utilized to measure E(j), the liquid junction potential. The operational pH values for four buffer solutions at 25 and 37 degrees C are calculated using the physiological phosphate buffer standard based on NBS/NIST convention. These solutions are recommended as pH standards in the pH range of 6.8 to 7.2 for physiological fluids.Journal of Solution Chemistry 04/2009; 38(4):471483. DOI:10.1007/s1095300993809 · 1.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: The values of the second dissociation constant, pK(2), and related thermodynamic quantities of 3[(1,1dimethyl2hydroxymethyl)amino]2hydroxypropanesulfonic acid (AMPSO) have already been reported in previous investigations at 12 temperatures over the temperature range (278.15 to 328.15) K, including 310.15 K (J. Solution Chem. 1997, 26, 309317). This paper reports the results for the pH of nine buffer solutions free of the chloride ion with compositions: (a) AMPSO, (0.04 mol.kg(1)) + NaAMPSO, (0.04 mol.kg(1)); (b) AMPSO (0.05 mol.kg(1)) + NaAMPSO (0.01 mol.kg(1)); (c) AMPSO (0.05 mol.kg(1)) + NaAMPSO (0.05 mol.kg(1)); (d) AMPSO (0.06 mol.kg(1)) + NaAMPSO (0.01 mol.kg(1)); (e) AMPSO (0.06 mol.kg(1)) + NaAMPSO, (0.02 mol.kg(1)); (f) AMPSO (0.06 mol.kg(1)) + NaAMPSO (0.03 mol.kg(1));(g) AMPSO (0.08 mol.kg(1)) + NaAMPSO (0.01 mol.kg(1)); (h) AMPSO (0.08 mol.kg(1)) + NaAMPSO (0.02 mol.kg(1)); and (i) AMPSO (0.08 mol.kg(1)) + NaAMPSO (0.08 mol.kg(1)). The remaining 13 buffer solutions 0 to v) have saline media of the ionic strength I = 0.16 mol.kg(1), matching closely to that of the physiological sample. Conventional pa(H) values, designated as pH(s), for all nine buffer solutions (a to i) without the chloride ion and thirteen buffer solutions with the chloride ion 0 to v) at I = 0.16 mol.kg(1) from (278.15 to 328.15) K have been calculated. The operational pH values for six buffer solutions at (298.15 and 310.15) K have been determined based on the difference in the values of the liquid junction potentials between the blood phosphate standard and the experimental buffer solutions. Five of these buffers are recommended as standards for the physiological pH range 7.5 to 8.5.Journal of Chemical & Engineering Data 01/2008; DOI:10.1021/je8004563 · 2.05 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: Electromotive force measurements have been made using the cell $$\mbox{In(s)}\mbox{HCl }(m_{\mathrm{A}}),\mbox{InCl}_{3}(m_{\mathrm{B}}),\mbox{H}_{2}\mbox{O}\mbox{AgCl, Ag}$$ in the ionic strength range of I=0.05, 0.1, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mol⋅kg−1 at 25 �C. The value of E o, the standard potential of the In/In3+ electrode, has been determined at 25 �C. Our value of E o (−0.3371 V) at 25 �C obtained from our measurements is in good agreement with −0.336 (Hakomori, J. Am. Chem. Soc. 52: 2372–2376, 1930) and −0.3382 V (Covington et al., J. Chem. Soc. 4394–4401, 1963). The activity coefficients of InCl3 as well as Harned interaction coefficients have been determined at 25 �C for each of the experimental ionic strengths at ionic strength fractions of 0.1, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 and 0.9 of HCl. Harned’s rule for the salt is obeyed at I=0.05,0.1 and 0.25 mol⋅kg−1 but the quadratic terms are needed for higher ionic strengths. These data, together with others for the activity coefficient of HCl in the same solutions, have been treated by the ioninteraction (Pitzer, Activity Coefficients in Electrolyte Solutions, CRC Press, 1991) equations in a previous publication.Journal of Solution Chemistry 11/2007; 36(11):16691677. DOI:10.1007/s109530079210x · 1.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: Values of the second thermodynamic dissociation constant pK2 of N[tris(hydroxymethyl)methyl3amino]propanesulfonic acid (Taps) have been determined at twelve temperatures from 278.15 K to 328.15 K including 310.15 K by measurements of the electromotiveforce for cells without liquid junction of the type: PtH2 (g, p∘ = 101.325 kPa)Taps (m1), NaTapsate (m2), NaCl (m3)AgClAg, where m denotes molality. The pK2 values for the dissociation of Taps are represented by the equation: pK2 = 2969.61 · (K/T) – 17.05052 + 2.73697 · ln(T/K). The values of pK2 for Taps were found to be (8.502 ± 0.0007) at T = 298.15 K and (8.225 ± 0.0009) at T = 310.15 K, respectively, indicating thereby to be useful as buffer solutions for pH control in the region 7.4 to 8.5. The thermodynamic quantities, ΔG∘, ΔH∘, ΔS∘, and dissociation process of Taps have been derived from the temperature coefficients of the pK2.The Journal of Chemical Thermodynamics 04/2006; 38(4):413417. DOI:10.1016/j.jct.2005.06.009 · 2.42 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: The values of the second dissociation constant, K 2, and related thermodynamic quantities of the ampholyte bis[(2hydroxyethyl)amino]acetic acid (BICINE) have been determined at temperatures from 5 to 55 ∘C. The pH values of six equimolal buffer solutions, and four buffer solutions having ionic strengths (I = 0.16 mol⋅kg−1) similar to those in blood plasma, have been evaluated at 12 temperatures from 5 to 55 ∘C using the Bates–Guggenheim convention. The liquid junction potentials (E j ) between the buffer solutions of BICINE and saturated KCl solution of the calomel electrode at 25 and 37 ∘C have been estimated by measurement with a flowing junction cell. These values of E j have been used to ascertain the operational pH values at 25 and 37 ∘C. The pK 2 values at 25 and 37 ∘C are 8.333 and 8.156, respectively. The thermodynamic quantities associated with the second acid dissociation have been calculated from the values of pK 2 as a function of temperature. The zwitterionic buffer BICINE was shown to be useful as a pH standard in the region close to that of blood serum.Journal of Solution Chemistry 03/2006; 35(4):605624. DOI:10.1007/s1095300590096 · 1.08 Impact Factor 
Article: Buffer Standards for the Physiological pH of the Zwitterionic Compound, TAPS, From 5 to 55 ∘C
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ABSTRACT: The values of the second dissociation constant, pK 2, and related thermodynamic quantities of N[tris(hydroxymethyl)methyl3amino]propanesulfonic acid (TAPS) have already been reported at 12 temperatures over the temperature range 5–55 ∘C, including 37 ∘C. This paper reports the results for the pH of five equimolal buffer solutions with compositions: (a) TAPS (0.03 mol⋅kg−1) + NaTAPS (0.03 mol⋅kg−1); (b) TAPS (0.04 mol⋅ kg−1) + NaTAPS (0.04 mol⋅kg−1); (c) TAPS (0.05 mol⋅kg−1) + NaTAPS (0.05 mol⋅kg−1); (d) TAPS (0.06 mol⋅kg−1) + NaTAPS (0.06 mol⋅kg−1); and (d) TAPS (0.08 mol⋅kg−1) + NaTAPS (0.08 mol⋅kg−1). The remaining eight buffer solutions consist of saline media of the ionic strength I = 0.16 mol⋅kg−1, matching closely to that of the physiological sample. The compositions are: (f) TAPS (0.04 molkg−1) + NaTAPS (0.02 molkg−1) + NaCl (0.14 mol⋅kg−1); (g) TAPS (0.05 mol⋅kg−1) + NaTAPS (0.04 mol⋅kg−1) + NaCl (0.12 mol⋅kg−1); (h) TAPS (0.6 mol⋅kg−1) + NaTAPS (0.04 mol⋅kg−1) + NaCl (0.12 mol⋅kg−1); (i) TAPS (0.08 mol⋅kg−1) + NaTAPS (0.06 mol⋅kg−1) + NaCl (0.10 mol⋅kg−1); (j) TAPS (0.04 mol⋅ kg−1) + NaTAPS (0.04 mol⋅kg−1) + NaCl (0.12 mol⋅kg−1); (k) TAPS (0.05 mol⋅kg−1) + NaTAPS (0.05 mol⋅kg−1) + NaCl (0.11 mol⋅kg−1); (l) TAPS (0.06 mol⋅kg−1) + NaTAPS (0.06 mol⋅kg−1) + NaCl (0.10 mol⋅kg−1); and (m) TAPS (0.08 mol⋅kg−1) + NaTAPS (0.08 mol⋅kg−1) + NaCl (0.08 mol⋅kg−1). These buffers are recommended as a pH standard for clinical measurements in the range of physiological application. Conventional pH values, designated as pH(s), for all 13 buffer solutions from 5 to 55 ∘C have been calculated. The operational pH values with liquid junction corrections, at 25 and 37 ∘C for buffer solutions, designated above as (b), (c), (d), (e), (j), (l), and (m); have been determined based on the difference in the values of the liquid junction potentials between the accepted phosphate standard and the buffer solutions under investigation.Journal of Solution Chemistry 03/2006; 35(4):551566. DOI:10.1007/s1095300590100 · 1.08 Impact Factor
Publication Stats
902  Citations  
193.16  Total Impact Points  
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Institutions

2001–2012

Drury University
 Chemistry
Springfield, Michigan, United States


1990–2000

University of Miami
 Rosenstiel School of Marine and Atmospheric Science
كورال غيبلز، فلوريدا, Florida, United States


1971–2000

Springfield College
Springfield, Missouri, United States


1983–1984

University of California, Berkeley
 Department of Chemistry
Berkeley, California, United States
