thiourea and phthalic-acid

thiourea has been researched along with phthalic-acid* in 2 studies

Other Studies

2 other study(ies) available for thiourea and phthalic-acid

Article	Year
Fast and precise method for HPLC-size exclusion chromatography with UV and TOC (NDIR) detection: importance of multiple detectors to evaluate the characteristics of dissolved organic matter. Water research, 2011, Nov-15, Volume: 45, Issue:18 A new type of high-performance liquid chromatography (HPLC)-size exclusion chromatography (SEC) system with ultraviolet (UV) absorbance detection and non-dispersive infrared (NDIR) detection of total organic carbon is described. The introduction of an online degassing tube and a low-volume HPLC column helped to reduce the analytical time and increase the sensitivity of the SEC system. This study is the first in which linear calibration curves (R(2)>0.99) were obtained for both UV absorbance and NDIR data for polystyrene sulfonate standards, which are the most suitable standards for molecular size analysis of aquatic humic substances as well as dissolved organic matter (DOM). Using the calibration curves, the molecular size distribution of DOM in water collected from Lake Kasumigaura and in pore water from lake sediments was estimated. Most of the DOM had a molecular weight less than 4000 Daltons (Da), and the amount of low-molecular-weight DOM (∼ 2000 Da) with low UV absorbance increased with depth in the sediment pore water. This result shows the importance of combining quantitative analysis by NDIR detection with qualitative analysis by UV detection to determine the chemical and physical properties of DOM. The possible sources and reactivity of DOM in Lake Kasumigaura and its sediment pore water are also discussed. Topics: Calibration; Carbon; Chromatography, Gel; Chromatography, High Pressure Liquid; Geography; Geologic Sediments; Glucose; Glutamic Acid; Japan; Lakes; Molecular Weight; Organic Chemicals; Phthalic Acids; Porosity; Reference Standards; Solubility; Thiourea; Ultraviolet Rays	2011
Binding of the terephthalate dianion by di- tri- and tetrathiourea functionalised fused [3] and [5]polynorbornane based hosts. Organic & biomolecular chemistry, 2009, Oct-21, Volume: 7, Issue:20 The affinity of new di-, tri- and tetrathiourea functionalised fused [3] and [5]polynorbornane based hosts 1-6 towards terephthalate2- was proportional to the size of the preorganised cleft/cavity imparted by the polynorbornane scaffold. Receptors based on the [5]polynobornane framework had greater affinities for the anion due to a higher degree of host:guest size complementarity. Hosts 1-5 formed 1:1 host:guest complexes with the rigid dianion, yet remarkably, host 6 was found to bind two terephthalate guests. Topics: Camphanes; Hydrogen Bonding; Magnetic Resonance Spectroscopy; Models, Molecular; Molecular Conformation; Phthalic Acids; Thiourea	2009

Article

Year

Fast and precise method for HPLC-size exclusion chromatography with UV and TOC (NDIR) detection: importance of multiple detectors to evaluate the characteristics of dissolved organic matter.

Water research, 2011, Nov-15, Volume: 45, Issue:18

A new type of high-performance liquid chromatography (HPLC)-size exclusion chromatography (SEC) system with ultraviolet (UV) absorbance detection and non-dispersive infrared (NDIR) detection of total organic carbon is described. The introduction of an online degassing tube and a low-volume HPLC column helped to reduce the analytical time and increase the sensitivity of the SEC system. This study is the first in which linear calibration curves (R(2)>0.99) were obtained for both UV absorbance and NDIR data for polystyrene sulfonate standards, which are the most suitable standards for molecular size analysis of aquatic humic substances as well as dissolved organic matter (DOM). Using the calibration curves, the molecular size distribution of DOM in water collected from Lake Kasumigaura and in pore water from lake sediments was estimated. Most of the DOM had a molecular weight less than 4000 Daltons (Da), and the amount of low-molecular-weight DOM (∼ 2000 Da) with low UV absorbance increased with depth in the sediment pore water. This result shows the importance of combining quantitative analysis by NDIR detection with qualitative analysis by UV detection to determine the chemical and physical properties of DOM. The possible sources and reactivity of DOM in Lake Kasumigaura and its sediment pore water are also discussed.

Topics: Calibration; Carbon; Chromatography, Gel; Chromatography, High Pressure Liquid; Geography; Geologic Sediments; Glucose; Glutamic Acid; Japan; Lakes; Molecular Weight; Organic Chemicals; Phthalic Acids; Porosity; Reference Standards; Solubility; Thiourea; Ultraviolet Rays

2011

Binding of the terephthalate dianion by di- tri- and tetrathiourea functionalised fused [3] and [5]polynorbornane based hosts.

Organic & biomolecular chemistry, 2009, Oct-21, Volume: 7, Issue:20

The affinity of new di-, tri- and tetrathiourea functionalised fused [3] and [5]polynorbornane based hosts 1-6 towards terephthalate2- was proportional to the size of the preorganised cleft/cavity imparted by the polynorbornane scaffold. Receptors based on the [5]polynobornane framework had greater affinities for the anion due to a higher degree of host:guest size complementarity. Hosts 1-5 formed 1:1 host:guest complexes with the rigid dianion, yet remarkably, host 6 was found to bind two terephthalate guests.

Topics: Camphanes; Hydrogen Bonding; Magnetic Resonance Spectroscopy; Models, Molecular; Molecular Conformation; Phthalic Acids; Thiourea

2009