Physical Chemical Studies of Calcium Oxalate Crystallization

Nancollas, G.H.; Smesko, S.A.; Campbell, Allison A.; Richardson, Carl; Johnsson, Mats; Ladiccico, Rachelle A.; Binette, J. P.; Binette, M.

doi:10.1016/s0272-6386(12)80629-9

Cited by 20 publications

(6 citation statements)

References 10 publications

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“…For comparison of the effect of sucrose on COM precipitation kinetics, the experimental data obtained for COM precipitation in both single- and binary-foulant systems were fitted to the simple rate equation: where C is the molar concentration of COM, k is a rate constant (mol/L·h), σ is the relative SS, and n is the order of reaction related to the mechanisms on which the crystallization process is based [i.e., values of n near unity suggest a bulk diffusion process during crystal growth, and n close to 2 indicates a surface-controlled mechanism; higher order ( n > 2) polynuclear mechanisms may also occur] . In eq 2, q t and q e are the ionic products (mol 2 /L 2 ) of Ca 2+ and Ox 2- at time t and at equilibrium, respectively.…”

Section: Methodsmentioning

confidence: 99%

Composite Fouling of Calcium Oxalate and Amorphous Silica in Sugar Solutions

Sheikholeslami

Doherty

2003

Ind. Eng. Chem. Res.

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The composite fouling of calcium oxalate monohydrate (COM) and SiO2 in the multi-effect evaporators is known to cause a variety of problems in sugar mills with serious technico-economical consequences. A batch experimental study has been conducted to characterize the COM−SiO2 interactions in both single- and binary-foulant systems in the presence of sucrose under conditions relevant to those in the sugar mill evaporators. The presence of sucrose increased the rates of COM precipitation and SiO2 polymerization and decreased the solubilities of COM and SiO2 in solution. Colloidal silica particles were formed at a lower threshold initial silica supersaturation (SS) of 1.8 in a single-foulant sucrose solution than that formed in water (2.0). Both promotory and inhibitory effects on the coprecipitation of COM−SiO2 thermodynamics and kinetics in the binary-foulant systems were observed, depending on the concentrations of COM and sucrose. The threshold silica SS at which silica colloids formed was further decreased (from SS = 1.8 to 1.3) by the presence of COM. These findings may be attributed to a number of factors such as adduct formation between COM, SiO2, and sucrose, adsorption of COM−sucrose complexes by polymeric SiO2−sucrose species, and the availability of water molecules.

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Section: Methodsmentioning

confidence: 99%

Composite Fouling of Calcium Oxalate and Amorphous Silica in Sugar Solutions

Sheikholeslami

Doherty

2003

Ind. Eng. Chem. Res.

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“…Thus, precise measurements of rates of formation of COM determined by CC analysis more accurately reflect the in vivo kinetics of crystallization. 18 In addition to its own role in stone formation and inhibition, citric acid, HOOC(CH 2 ) 2 CH(COOH)(CH 2 ) 2 COOH, has also served as a model for the more complicated naturally occurring proteins that are also rich in the carboxylates of acidic amino acids. AFM measurements of adhesion forces between molecules immobilized on AFM probes and crystals have shown binding of carboxylates to the COM crystal surface.…”

Section: Introductionmentioning

confidence: 99%

Constant Composition Studies Verify the Utility of the Cabrera−Vermilyea (C-V) Model in Explaining Mechanisms of Calcium Oxalate Monohydrate Crystallization

Wang

Yoreo

Guan

et al. 2006

Crystal Growth & Design

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The classic theory of Cabrera and Vermilyea (C-V) postulates that inhibition of crystallization by impurities is the result of pinning of step motion. Although generally accepted, the predictions of the C-V model have not been previously linked to studies of impurity adsorption in macroscopic crystallization systems. Since calcium oxalate monohydrate (COM) is the primary constituent of most human kidney stones, effects of impurities on COM crystallization are biologically relevant. Recent in situ atomic force microscopy (AFM) studies suggest that citrate molecules adsorb to COM step edges on the (-101) face, thereby pinning step motion and decreasing the velocity of the steps. We have now investigated the crystallization kinetics of COM in the presence of citrate at 37 °C and I ) 0.15 mol L -1 using the constant composition (CC) method. The dependence of growth rate on both supersaturation and citrate concentration were measured, and the behavior of the COM-citrate system was found to be in reasonable agreement with the predictions of the C-V model, provided that, in addition to pinning of step motion on the (-101) face through the Gibbs-Thomson effect, the kinetic coefficient that relates step speed to supersaturation is assumed to decrease with increasing citrate levels on all faces. The dependence of macroscopic crystal aspect ratio on citrate level in these CC studies also fits this model. Thus, we find that the results provide a mechanistic link between the microscopic AFM measurements of step kinetics and the macroscopic CC data on crystal growth rates and crystal habit.

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“…and n is the reaction order [17]. The supersaturation ratio is the ratio of the product of the free ion activities (denoted by oq) and the solubility product :…”

Section: Introductionmentioning

confidence: 99%

Calcium oxalate crystallization kinetics studied by oxalate-induced turbidity in fresh human urine and artificial urine

2000

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We have studied the kinetics of oxalate-induced turbidity in fresh human urine and artificial urine. Assays are performed in 96-well plates, which allows many oxalate concentrations to be studied, repeatedly, in a short time. The metastable limit is defined in terms of the lowest oxalate concentration that gives a rate of change of attenuance significantly greater than the control. Interpretation of rates above this limit is based on ln/ln plots of initial rates against added oxalate concentration. This approach has a good theoretical basis, is well supported by our results and gives a turbidity rate index that is related to the product of the growth rate constant and a factor relating to the number and characteristics of the heteronuclei responsible for initiation of crystallization. This interpretation is posited upon the assumptions that second-order crystallization kinetics occur in unseeded urine when supersaturation exceeds the metastable limit and that aggregation during the initial phase of crystallization does not significantly contribute to changes in turbidity. Metastable limits of urine from healthy volunteers corresponded to a calcium oxalate supersaturation ratio of approx. 10. The turbidity rate index was higher in human urine than in artificial urine. The metastable limit, based on either oxalate concentration or supersaturation, for induction of calcium oxalate crystallization in normal human urine is higher than is likely to be found in normal subjects in vivo. The shape of the relationship between the metastable limit (based on oxalate concentration) and calcium concentration emphasizes the benefit of achieving a low urine calcium concentration. Comparison of the turbidity rate indices for human and artificial urine suggests that the role of nucleation promoters is more dominant than that of growth inhibitors.

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Physical Chemical Studies of Calcium Oxalate Crystallization

Cited by 20 publications

References 10 publications

Composite Fouling of Calcium Oxalate and Amorphous Silica in Sugar Solutions

Composite Fouling of Calcium Oxalate and Amorphous Silica in Sugar Solutions

Constant Composition Studies Verify the Utility of the Cabrera−Vermilyea (C-V) Model in Explaining Mechanisms of Calcium Oxalate Monohydrate Crystallization

Calcium oxalate crystallization kinetics studied by oxalate-induced turbidity in fresh human urine and artificial urine

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