Single-ion enthalpies and entropies of transfer from water to aqueous urea solutions at 298.15 K

1992 ◽  
Vol 70 (6) ◽  
pp. 1666-1670 ◽  
Author(s):  
Andrew W. Hakin ◽  
Colin L. Beswick
Keyword(s):  
Sodium Iodide ◽  
Mixed Solvent ◽  
Solvent System ◽  
Enthalpies Of Solution ◽  
Enthalpies Of Transfer ◽  
Aqueous Urea ◽  
Tetraphenylarsonium Chloride ◽  
The Impact ◽  
Reference Electrolyte ◽  
Enthalpy Data

In this paper we report enthalpies of solution at infinite dilution [Formula: see text] at 298.15 K for tetraphenylarsonium chloride (Ph4AsCl), sodium tetraphenylborate (NaBPh4), sodium chloride (NaCl), sodium bromide (NaBr), and sodium iodide (NaI) in water and aqueous solutions containing 5, 10, 20, and 30% urea by weight. Enthalpies of transfer from water to aqueous urea solutions are reported. Single-ion enthalpies of transfer [Formula: see text] have been calculated using the tetraphenylarsonium tetraphenylborate, (TATB) reference electrolyte assumption. These single-ion enthalpy data have been combined with single-ion Gibbs functions of transfer [Formula: see text] reported in the literature to obtain single-ion entropies of transfer [Formula: see text] for the urea + water mixed solvent system. The results of this single-ion analysis are discussed in terms of the impact of electrolytes on the structure of aqueous urea solutions.

Lanasol dyes and wool fibres. Part I: model studies on the mechanism of dye fixation in a mixed solvent system

1998 ◽  
Vol 39 (4) ◽  
pp. 291-312 ◽  
Author(s):  
J.S. Church ◽  
A.S. Davie ◽  
P.J. Scammells ◽  
D.J. Tucker
Keyword(s):  
Mixed Solvent ◽  
Solvent System ◽  
Mixed Solvent System ◽  
Model Studies

Statistical Optimization and Kinetic Modeling of Lipase-Catalyzed Synthesis of Diacylglycerol in the Mixed Solvent System of Acetone/tert-Butanol

2021 ◽  
Vol 60 (39) ◽  
pp. 14026-14037
Author(s):  
Nurul Nadiah Abd Razak ◽  
Lai Ti Gew ◽  
Yolande Pérès ◽  
Patrick Cognet ◽  
Mohamed Kheireddine Aroua
Keyword(s):  
Kinetic Modeling ◽  
Mixed Solvent ◽  
Solvent System ◽  
Statistical Optimization ◽  
Mixed Solvent System ◽  
Tert Butanol

scholarly journals Thin Layer Chromatographic Analysis of Food Colorants from Three Morphotypes of Annatto (Bixa orellana L.)

2013 ◽  
Vol 2 (1) ◽  
pp. 7-12
Author(s):  
Hari Pada Seal ◽  
Mohammad Amdad Ali ◽  
Md Usuf Ali ◽  
Mosammat Hasina Akhter ◽  
Fowzia Sultana
Keyword(s):  
Thin Layer ◽  
Chromatographic Analysis ◽  
Mixed Solvent ◽  
Solvent System ◽  
Bixa Orellana ◽  
Solvent Extraction Method ◽  
Solvent Systems ◽  
Carrier Solvent ◽  
Thin Layer Chromatographic Analysis ◽  
Layer Chromatography

This article describes a simple solvent extraction method for the extraction of colorants from the three morphotypes such as, (Morphotype-1 (M1), Morphotype-2 (M2), and Morphotype- 3 (M3) of Annatto (Bixa orellana L.) seeds, and their separation, vivid, and qualitative demonstration by thin-layer chromatography. Several solvent systems (hexane, chloroform, acetone, ethanol, and a mixed-solvent having composition of CHCl3/C2H5OH/CH3COOH (80:2:1)) were applied for extraction of colored components. It was observed that a large portion of colorants was extracted by chloroform. Its effluent was deep brick red in color and transparent. Furthermore, various carrier solvent systems (Benzene-Ethyl acetate) were used to separate the components from the extracts. Carrier solvent system with the ratio of 7:3 was found as superior solvent for chloroform extracts. Three colored-spots were observed for all morphotypes. Among them, the first one was yellow colored having very low polarity and the second and third spots were both redbrick colored having medium and higher polarity respectively. In addition, for M1 no colorless-spot was observed in low and medium polar systems, revealing that the amount of wax and gum were minimum in the extract and superior morphotype among the three. DOI: http://dx.doi.org/10.3329/ijarit.v2i1.13987 Int. J. Agril. Res. Innov. & Tech. 2 (1): 7-12, June, 2012

scholarly journals Perchlorate versus other environmental sodium/iodide symporter inhibitors: potential thyroid-related health effects

2006 ◽  
Vol 155 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Bert De Groef ◽  
Brigitte R Decallonne ◽  
Serge Van der Geyten ◽  
Veerle M Darras ◽  
Roger Bouillon
Keyword(s):  
Drinking Water ◽  
Sodium Iodide ◽  
Competitive Inhibitor ◽  
Potential Effect ◽  
Iodine Intake ◽  
Iodine Uptake ◽  
Sodium Iodide Symporter ◽  
National Academy Of Sciences ◽  
Uptake Inhibition ◽  
The Impact

Objective: Perchlorate is a known competitive inhibitor of the sodium/iodide symporter (NIS). Possible thyroid-related effects of environmental perchlorate have created great health concerns, especially in the US, resulting in a debated reference dose (RfD) of 0.0007 mg/kg per day in drinking water recommended by the National Academy of Sciences (NAS). However, the impact of other environmental NIS inhibitors and the role of iodine seem to have received little attention in the whole debate. Methods: We performed a PubMed search for articles published up to February 2006, using the key terms perchlorate, nitrate, thiocyanate, iodine, NIS, RfD, thyroid (alone or in combinations), with particular attention for human studies. In parallel, we critically analysed the January 2005 NAS’ report, entitled ‘Health implications of perchlorate ingestion’. Results: The relative potencies of prevalent environmental NIS inhibitors (nitrate, thiocyanate and perchlorate) to inhibit iodine uptake have been estimated repeatedly with robust results. Our calculations show that nitrate and thiocyanate, acquired through drinking water or food, account for a much larger proportion of iodine uptake inhibition than perchlorate. Furthermore, the iodine uptake inhibitory effects of nitrate and thiocyanate – as defined by their legally accepted maximal contaminant levels in drinking water – exceed the potential effect of the proposed RfD for perchlorate by far. Conclusions: Iodine uptake inhibition and any potential downstream effect by perchlorate are highly dependent on the presence of other environmental NIS inhibitors and iodine intake itself. These potential confounders should therefore be considered in future studies and calculations for risk assessment.

Sign in / Sign up

Export Citation Format

Share Document