Melting Points and the Characterization of Organic Compounds

2009 ◽  
Vol 86 (1) ◽  
pp. 23 ◽  
Author(s):  
William B. Jensen
Keyword(s):  
Organic Compounds ◽  
Melting Points

Characterization of Soluble Organic Compounds and Complexation of Copper, Nickel, and Zinc in Extracts of Sludge-amended Soils

1987 ◽  
Vol 16 (4) ◽  
pp. 341-348 ◽  
Author(s):  
L. M. Dudley ◽  
B. L. McNeal ◽  
J. E. Baham ◽  
C. S. Coray ◽  
H. H. Cheng
Keyword(s):  
Organic Compounds ◽  
Amended Soils ◽  
Copper Nickel

Separation and Characterization of Standard Propoxyphene Diastereomers and Their Determination in Pharmaceutical and Illicit Preparations

1981 ◽  
Vol 64 (4) ◽  
pp. 875-883
Author(s):  
Shiv K Soni ◽  
Daniel Van Gelder
Keyword(s):  
High Pressure ◽  
Optical Isomers ◽  
Gold Chloride ◽  
Melting Points ◽  
Eutectic Melting ◽  
Racemic Mixtures ◽  
The Individual ◽  
Isomeric Mixtures ◽  
Asymmetric Carbon

Abstract Due to the existence of 2 asymmetric carbon atoms in: the propoxyphene molecule, there are 4 diastereomers: alpha dextro, alpha levo, beta dextro, and beta levo. Only α-d-propoxyphene is included under the federal Controlled Substances Act. Baseline separations of propoxyphene from various incipients (aspirin, caffeine, phenacetin, and acetaminophen) present in pharmaceutical and illicit preparations, and between the alpha and beta diastereomers, were achieved by high pressure liquid chromatography. The column eluant was collected and propoxyphene was extracted. The optical isomers were differentiated and characterized by melting points and by chemical microcrystalline tests. Using hot stage thermomicroscopy, the eutectic melting points of binary isomeric mixtures of propoxyphene bases and salts were found to be depressed about 10° and 15-30°C, respectively, below the individual isomer melting points. The characteristic microcrystals formed with the alpha racemic mixtures by using a glycerin-aqueous gold chloride reagent were not produced by the beta racemic mixtures.

scholarly journals Halogenated Volatile Organic Compounds in Water Samples and Inorganic Elements Levels in Ores for Characterizing a High Anthropogenic Polluted Area in the Northern Latium Region (Italy)

2021 ◽  
Vol 18 (4) ◽  
pp. 1628
Author(s):  
Mario Vincenzo Russo ◽  
Ivan Notardonato ◽  
Alberto Rosada ◽  
Giuseppe Ianiri ◽  
Pasquale Avino
Keyword(s):  
Organic Compounds ◽  
Mean Value ◽  
Greenhouse Crops ◽  
River Waters ◽  
Liquid Liquid Extraction ◽  
Volatile Organic ◽  
High Concentrations ◽  
Very High ◽  
Inorganic Fraction

This paper shows a characterization of the organic and inorganic fraction of river waters (Tiber and Marta) and ores/soil samples collected in the Northern Latium region of Italy for evaluating the anthropogenic/natural source contribution to the environmental pollution of this area. For organic compounds, organochloride volatile compounds in Tiber and Marta rivers were analyzed by two different clean-up methods (i.e., liquid–liquid extraction and static headspace) followed by gas chromatography–electron capture detector (GC-ECD) analysis. The results show very high concentrations of bromoform (up to 1.82 and 3.2 µg L−1 in Tiber and Marta rivers, respectively), due to the presence of greenhouse crops, and of chloroform and tetrachloroethene, due to the presence of handicrafts installations. For the qualitative and quantitative assessment of the inorganic fraction, it is highlighted the use of a nuclear analytical method, instrumental neutron activation analysis, which allows having more information as possible from the sample without performing any chemical-physical pretreatment. The results have evidenced high levels of mercury (mean value 88.6 µg g−1), antimony (77.7 µg g−1), strontium (12,039 µg g−1) and zinc (103 µg g−1), whereas rare earth elements show levels similar to the literature data. Particular consideration is drawn for arsenic (414 µg g−1): the levels found in this paper (ranging between 1 and 5100 µg g−1) explain the high content of such element (as arsenates) in the aquifer, a big issue in this area.

Characterization of biogenic volatile organic compounds (BVOCs) in cleaning reagents and air fresheners in Hong Kong

2011 ◽  
Vol 45 (34) ◽  
pp. 6191-6196 ◽  
Author(s):  
Yu Huang ◽  
Steven Sai Hang Ho ◽  
Kin Fai Ho ◽  
Shun Cheng Lee ◽  
Yuan Gao ◽  
...  
Keyword(s):  
Hong Kong ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Biogenic Volatile Organic Compounds ◽  
Volatile Organic

Estimation of Melting Points of Organic Compounds-II

2006 ◽  
Vol 95 (12) ◽  
pp. 2562-2618 ◽  
Author(s):  
Akash Jain ◽  
Samuel H. Yalkowsky
Keyword(s):  
Organic Compounds ◽  
Melting Points

Solid state chemical ionization for characterization of organic compounds by laser mass spectrometry

Talanta ◽  
1989 ◽  
Vol 36 (1-2) ◽  
pp. 117-124 ◽  
Author(s):  
Kesagapillai Balasanmugam ◽  
Somayajula Kasi Viswanadham ◽  
David M. Hercules
Keyword(s):  
Mass Spectrometry ◽  
Solid State ◽  
Organic Compounds ◽  
Chemical Ionization ◽  
Laser Mass Spectrometry ◽  
State Chemical

Chemical Characterization of Dissolved Organic Compounds from Coastal Sea Surface Microlayers (Baltic Sea, Germany)

2012 ◽  
Vol 46 (19) ◽  
pp. 10455-10462 ◽  
Author(s):  
Manuela van Pinxteren ◽  
Conny Müller ◽  
Yoshiteru Iinuma ◽  
Christian Stolle ◽  
Hartmut Herrmann
Keyword(s):  
Baltic Sea ◽  
Organic Compounds ◽  
Chemical Characterization ◽  
Sea Surface ◽  
Coastal Sea ◽  
Dissolved Organic Compounds
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