Description: This article discusses experimental artifacts and determination of accurate Py values. Abstract: Recently the Py solvent scale has been introduced and a large body of data has been generated using fluorescence measurements. Numerous problems exist in the correct determination of these values, including instrumental and chemical artifacts. Among the instrumental problems associated with correct Py assignments are slit width effects, inner filtering and efficiencies associated with double-pass vs. single-pass cell compartment designs. These instrumental problems, together with chemical artifacts related to adequate blank correction and temperature control, were investigated in the work reported in this paper.

Description: This article discusses estimating solid-liquid phase change enthalpies and entropies. Abstract: A group additivity method based on molecular structure is described that can be used to estimate solid-liquid total phase change entropy (∆₀ᵀ(fus)S(tpce)) and enthalpy (∆₀ᵀ(fus)H(tpce)) of organic molecules. The estimation of these phase changes is described and numerous examples are provided to guide the user in evaluating these properties for a broad range of organic structures. A total of 1858 compounds were used in deriving the group values and these values are tested on a database of 260 additional compounds. The absolute average and relative errors between experimental and calculated values for these 1858 compounds are 9.9 J-mol⁻¹·K⁻¹ and 3.52 kJ·mol⁻¹, and 0.154 and 0.17 for ∆₀ᵀ(fus)S(tpce) and ∆₀ᵀ(fus)H(tpce), respectively. For the 260 test compounds, standard deviations of ± 13.0 J·mol⁻¹·K⁻¹ (∆₀ᵀ(fus)S(tpce)) and ±4.88 kJ mol⁻¹ (∆₀ᵀ(fus)H(tpce)) between experimental and calculated values were obtained. Estimations are provided for both databases. Fusion enthalpies for some additional compounds not included in the statistics are also included in the tabulation.

Description: This article discusses the solubility of polycyclic aromatic hydrocarbons in pure and organic solvent mixtures. Abstract: This work updates Vols. 54, 58, and 59 in the IUPAC Solubility Data Series and presents solubility data for polycyclic aromatic hydrocarbon solutes dissolved in binary organic solvent mixtures. Published solubility data for anthracene, naphthalene, phenanthrene, phenothiazine, and pyrene that appeared in the primary literature between 1995 to the end of 2011 are compiled and critically evaluated. Experimental solubility data for 360 different solute-binary solvent systems are included in the volume. Solubility data published prior to 1995 were contained in three earlier volumes (Vols. 54, 58, and 59) and are not repeated in this volume.

Description: This articles discusses the spatial distribution of solutes in Aquifer outcrop zones along the Brazos River in east-central, Texas. Concentrations of several solutes - nitrate, arsenic, sulfate, boron, chloride, and bromide - along with total dissolved solids (TDS) in ten counties bordering the Brazos River in east-central, Texas were compiled, mapped, and analyzed relative to regional land use and geology. Agriculture and oil/gas production are major activities and potential sources of groundwater contamination in the study area. Data were compiled from 104 water wells with a median depth of 446 ft (136 m) in the outcrop zones of six sedimentary aquifers: Carizzo-Wilcox, Queen City, Sparta, Yegua-Jackson, Gulf Coast, and Brazos Alluvium. Only two observations surpassed the 44.3 mg/L drinking water standard for nitrate, and four observations exceeded the 10 ug/L standard for arsenic. The median chloride concentration was 53 mg/L; however, the maximum level was almost three times the secondary drinking water standard of 250 mg/L. Chloride, bromide, sulfate, and boron concentrations resembled TDS patterns, with numerous samples exceeding secondary TDS drinking water standards in the Yegua-Jackson Aquifer. Most chloride/bromide ratios were between 100 and 300. Overall, results of this study suggest that natural processes exert a primary control on ...

Description: This article is a response to "A critique of Abraham and Acree's correlation for deca-1,9-diene/water partition coefficients." Abstract: The manuscript responds to the critique of Nitsche and Kasting concerning our published correlation for deca-1,9-diene-water partition coefficients. Several statements made in the critique are refuded, and shown to be misrepresentations of ideas contained in our earlier paper.