Corrigendum to “Specific-ion Effects in Non-Aqueous Systems” [Curr Opin Colloid Interface Sci 23 (June 2016) 82–93](S135902941630067X)(10.1016/j.cocis.2016.06.009)

Due to our continued research in the field, we have realised that the ordering of ions of Figure 2 needs to be rectified. Figure 2 is to be replaced by the following figure and caption: Fig. 2 The Hofmeister and lyotropic series of cations in water. The cations of the Hofmeister series are ordered from most effective in precipitating proteins out of solution at the top to least effective at the bottom. The series is obtained by combining the series reported in references [13,80,81,83,86-89]. The ion is positioned in its most commonly agreed ranking, and bars show the reported variations in position among different publications. The ethyl- to butylammonium cations ordering is known with respect to the tetramethylammonium ion, but not to the other cations in the series with certainty. A white line has therefore been drawn around these ions to mark the discontinuity. The cations of the lyotropic series are ordered from smallest to largest lyotropic number: the series defined by Voet[23] is integrated with the one from Marcus [22]. [Figure presented] The difference from the original figure is that the ordering of the alkali metal cations, bivalent cations and guanidinium is now reversed, with the most effective cations at precipitating proteins now correctly on top; in addition, the relative positioning of the tetraalkylammonium ions with respect to the alkali metal cations is corrected (their ordering was correct in the original figure and need not be reversed). This correction does not change the overall discussion, findings and conclusions made in the paper. Nevertheless, a number of identifications of the Hofmeister series trend for the alkali metal cations across the paper are in need of being updated in light of this correction. That is the series as shown in the paper needs to be reversed. The amended tables are listed below: Table 1 Trends in specific-ion effects observed in water. Data from [22] [Figure presented] Table 2 Trends in specific-ion effects observed in methanol. Data from [22] [Figure presented] Table 3 Additional trends in specific-ion effects observed in methanol. [Figure presented] Table 4 Trends in specific-ion effects observed in formamide. Data from [22] [Figure presented] Table 5 Trends in specific-ion effects observed in ethanol. Data from [22] [Figure presented] Table 6 Trends in specific-ion effects observed in N-methylformamide. Data from [22] [Figure presented] Table 7 Trends in specific-ion effects observed in DMF. Data from [22] unless otherwise indicated in the table [Figure presented] Table 8 Trends in specific-ion effects observed in DMSO. Data from [22] [Figure presented] Table 9 Trends in specific-ion effects observed in PC and EC. Data from [22] [Figure presented] Table 11 Summary of the specific-ion effects series seen for a range of experiments in water and non-aqueous solvents. Protic solvents are in bold, aprotic solvents are italicised. Series with 3 or less ions have been indicated in parentheses. [Figure presented] The changes are also detailed below. • The background of the MRT cells in Tables 1 and 2 should be light orange (reverse Hofmeister);• The RDD column in table 1, 4 and 6 should have no coloured background;• The MHC alkali metals column needs to be changed. The series that were previously identified as reversed Hofmeister are instead forward Hofmeister (Tables 2, 5, 7, 8, 9), the cells background should therefore be light yellow instead of light orange. The trend in the NMF column of Table 6 should be identified as forward Hofmeister too;• In the LMC ammonium family column the cells corresponding to MeOH, EtOH and NMF (Tables 2, 5 and 6) display a forward Hofmeister series (previously identified as “other”), and should be highlighted in light yellow;• In the VBC ammonium column the MeOH and F cells (Tables 3 and 4) should display a reverse-Hofmeister series (previously identified as other), and should be coloured in light orange.• In table 3, the NMR hydroxyl proton chemical shift at 40°C column should be identified as forward Hofmeister (light yellow background), and the vapour pressure depression column should be reverse Hofmeister (light orange) instead of forward Hofmeister;• In Table 7, the “reduction of SO₂” column should show a reverse Hofmeister series (light orange background) rather than a forward Hofmeister for the lithium, sodium and potassium cells. The tetraethylammonium ion must now be excluded from the series (no coloured cell background);• The above-listed changes are summarised below in the summary table for cations (table 11), where the series that have changed are highlighted in red: [Figure presented] In addition, references 77-88 are missing from the reference list of the original paper, and are the following: [77] Maiti K, Mitra D, Guha S, Moulik SP. Salt effect on self-aggregation of sodium dodecylsulfate (SDS) and tetradecyltrimethylammonium bromide (TTAB): Physicochemical correlation and assessment in the light of Hofmeister (lyotropic) effect. J Mol Liq 2009;146:44–51. https://doi.org/10.1016/j.molliq.2009.01.014.[78] Pinna MC, Salis A, Monduzzi M, Ninham BW. Hofmeister series: the hydrolytic activity of Aspergillus niger lipase depends on specific anion effects. J Phys Chem B 2005;109:5406–8. https://doi.org/10.1021/jp050574w.[79] Zhang Y, Cremer PS. Chemistry of Hofmeister anions and osmolytes. Annu Rev Phys Chem 2010;61:63–83. https://doi.org/10.1146/annurev.physchem.59.032607.093635.[80] von Hippel PH, Wong K-Y. Neutral Salts: The Generality of Their Effects on the Stability of Macromolecular Conformations. Science (80-) 1964;145:577–80. https://doi.org/10.1126/science.145.3632.577.[81] Von Hippel PH, Schleich T. Ion effects on the solution structure of biological macromolecules. Acc Chem Res 1969;2:257–65. https://doi.org/10.1021/ar50021a001.[82] Kunz W. Specific ion effects in colloidal and biological systems. Curr Opin Colloid Interface Sci 2010;15:34–9. doi:10.1016/j.cocis.2009.11.008.[83] Zhao H. Protein Stabilization and Enzyme Activation in Ionic Liquids: Specific Ion Effects. J Chem Technol Biotechnol 2016;91:25–50. https://doi.org/10.1002/jctb.4837.[84] Hamaguchi K, Geiduschek EP. The Effect of Electrolytes on the Stability of the Deoxyribonucleate Helix. J Am Chem Soc 1962;84:1329–38. https://doi.org/10.1021/ja00867a001.[85] Hanstein WG. Chaotropic ions and their interactions with proteins. J Solid-Phase Biochem 1979;4:189–206. https://doi.org/10.1007/BF02991894.[86] Fischer MH, Moore G. On the swelling of fibrin. Am J Physiol Content 1907;20:330–42.[87] Carpenter DC, Lovelace FE. The Influence of Neutral Salts on the Optical Rotation of Gelatin. III. Effect of the Halides of Lithium, Sodium, Rubidium and Cesium 1. J Am Chem Soc 1935;57:2337–42. https://doi.org/10.1021/ja01315a001.[88] Arakawa T, Timasheff SN. Mechanism of protein salting in and salting out by divalent cation salts: balance between hydration and salt binding. Biochemistry 1984;23:5912–23. https://doi.org/10.1021/bi00320a004. To which an additional reference introduced for figure 2 in the present correction should be added:[89] Jain S, Ahluwalia JC. Differential scanning calorimetric studies on the effect of ammonium and tetraalkylammonium halides on the stability of lysozyme. Biophys. Chem. 1996;59:171–7. https://doi.org/10.1016/0301-4622(9500135-2).