The behavior of ions in water is controlled by their water affinity
JournalQuarterly reviews of biophysics
PublisherCambridge University Press
MetadataShow full item record
AbstractThe strong, long-range electrostatic forces described by Coulomb’s law disappear for ions in water, and the behavior of these ions is instead controlled by their water affinity – a weak, short-range force which arises from their charge density. This was established experimentally in the mid-1980s by size-exclusion chromatography on carefully calibrated Sephadex® G-10 (which measures the effective volume and thus the water affinity of an ion) and by neutron diffraction with isotopic substitution (which measures the density and orientation of water molecules near the diffracting ion and thus its water affinity). These conclusions have been confirmed more recently by molecular dynamics simulations, which explicitly model each individual water molecule. This surprising change in force regime occurs because the oppositely charged ions in aqueous salt solutions exist functionally as ion pairs (separated by 0, 1 or 2 water molecules) as has now been shown by dielectric relaxation spectroscopy; this cancels out the strong long-range electrostatic forces and allows the weak, short-range water affinity effects to come to the fore. This microscopic structure of aqueous salt solutions is not captured by models utilizing a macroscopic dielectric constant. Additionally, the Law of Matching Water Affinity, first described in 1997 and 2004, establishes that contact ion pair formation is controlled by water affinity and is a major determinant of the solubility of charged species since only a net neutral species can change phases.
Identifier to cite or link to this itemhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85075115564&doi=10.1017%2fS0033583519000106&partnerID=40&md5=1210a5ac72c2eab41e0b0792e9098206; http://hdl.handle.net/10713/11467
- Why continuum electrostatics theories cannot explain biological structure, polyelectrolytes or ionic strength effects in ion-protein interactions.
- Authors: Collins KD
- Issue date: 2012 Jun
- Water-mediated ion-ion interactions are enhanced at the water vapor-liquid interface.
- Authors: Venkateshwaran V, Vembanur S, Garde S
- Issue date: 2014 Jun 17
- Spiers Memorial Lecture. Ions at aqueous interfaces.
- Authors: Jungwirth P
- Issue date: 2009
- Ions from the Hofmeister series and osmolytes: effects on proteins in solution and in the crystallization process.
- Authors: Collins KD
- Issue date: 2004 Nov
- Correlation forces between helical macro-ions in the weak coupling limit.
- Authors: Lee DJ
- Issue date: 2011 Mar 16
Showing items related by title, author, creator and subject.
Reviving the "Moore Swab": a Classic Environmental Surveillance Tool Involving Filtration of Flowing Surface Water and Sewage Water To Recover Typhoidal Salmonella BacteriaSikorski, M.J.; Levine, M.M. (American Society for Microbiology, 2020)The "Moore swab" is a classic environmental surveillance tool whereby a gauze pad tied with string is suspended in flowing water or wastewater contaminated with human feces and harboring enteric pathogens that pose a human health threat. In contrast to single volume "grab" samples, Moore swabs act as continuous filters to "trap" microorganisms, which are subsequently isolated and confirmed using appropriate laboratory methods. Continuous filtration is valuable for the isolation of transiently present pathogens such as human-restricted Salmonella enterica serovars Typhi and Paratyphi A and B. The technique was first proposed (1948) to trace Salmonella Paratyphi B systematically through sewers to pinpoint the residence of a chronic carrier responsible for sporadic outbreaks of paratyphoid fever. From 1948 to 1986, Moore swabs proved instrumental to identify long-term human reservoirs (chronic carriers) and long-cycle environmental transmission pathways of S Typhi and Paratyphi, for example, to decipher endemic transmission in Santiago, Chile, during the 1980s. Despite limitations such as intermittent shedding of typhoidal Salmonella by humans and the effects of dilution, S Typhi and S Paratyphi have been recovered from sewers, surface waters, irrigation canals, storm drains, flush toilets, and septic tanks by using Moore swabs. Driven by the emergence of multiple antibiotic-resistant S Typhi and S Paratyphi A strains that limit treatment options, several countries are embarking on accelerated typhoid control programs using vaccines and environmental interventions. Moore swabs, which are regaining appreciation as important components of the public health/environmental microbiology toolbox, can enhance environmental surveillance for typhoidal Salmonella, thereby contributing to the control of typhoid fever. Copyright 2020 Sikorski and Levine.
A dissertation concerning the use of sea water in diseases of the glands, &c. to which is added An epistolary dissertation to R. Frewin, M.D.Russell, Richard, 1687-1759 (Oxford : Printed at the Theatre: and sold by James Fletcher ... and J. J. Rivington ..., 1753)
Description of a glass apparatus, for making mineral waters : like those of Pyrmont, Spa, Seltzer, &c. in a few minutes, and with a very little expence : together with the description of some new eudiometers, or instruments for ascertaining the wholesomeness of respirable air, and a method of using these instruments, in a letter to the Rev. Dr. Priestley ...Magalhães, João Jacinto de, 1722-1790. (London: Printed for W. Parker...and sold by J. Johnson...and W. Brown..., 1779)