Identification and Determination of Polymers in Compounded Cured Rubber Stocks by Pyrolysis and Two-Channel Gas Chromatography

1966 ◽  
Vol 39 (2) ◽  
pp. 259-277 ◽  
Author(s):  
H. M. Cole ◽  
D. L. Petterson ◽  
V. A. Sljaka ◽  
D. S. Smith
Keyword(s):  
Gas Chromatography ◽  
Quantitative Analysis ◽  
Chromatographic Analysis ◽  
Raw Materials ◽  
Temperature Programming ◽  
Pyrolysis Products ◽  
Rubber Industry ◽  
Flame Ionization ◽  
Dual Channel

Abstract Methods for analysis of carbon-black-loaded vulcanizates are of considerable interest to the rubber industry and to those supplying its raw materials. Identification of polymers or copolymers present in such stocks is an important step in this analysis. Often it becomes desirable also to determine the composition of a blend of two or more elastomers. In recent years gas chromatographic analysis of volatile pyrolysis products has been increasingly applied to these intractable materials. A wide variety of polymers and experimental techniques for pyrolysis and subsequent chromatographic analysis have been used. A complete resume of this work is beyond the scope of this report, but recent papers dealing with the use of these methods in elastomer analysis include those of Groten, Hulot and Lebel, Blenkin, Lebel, Fiorenza and Bonomi, and an excellent review of pyrolytic techniques by Brauer. This study was an evaluation of the applicability of simultaneous flame ionization and electron capture (dual-channel) chromatography, with or without temperature programming to polymer identification and to quantitative analysis of elastomer blends.

scholarly journals Authenticity control of pine sylvestris essential oil by chiral gas chromatographic analysis of α-pinene

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Martina Allenspach ◽  
Claudia Valder ◽  
Daniela Flamm ◽  
Christian Steuer
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Analysis ◽  
Enantiomeric Excess ◽  
Ionization Detector ◽  
Pine Oil ◽  
Flame Ionization ◽  
Enantiomeric Ratio ◽  
Chiral Gas Chromatography

AbstractNumerous terpenes present in essential oils (EOs) display one or more chiral centers. Within the same genus the enantiomeric ratio of these compounds can be different. Thus, the determination of enantiomers is a valuable tool to evaluate authenticity and quality of EOs. In here, the terpene profile of primary and commercial pine EOs was analyzed by conventional and chiral gas chromatography coupled to a flame ionization detector. The enantiomeric excess of ( ±)-α-pinene was determined and significant differences between primary and commercially available EOs were observed. Primary EOs of Pinus sylvestris L. showed a positive enantiomeric excess of (+)-α-pinene whereas commercial EOs labeled as P. sylvestris L. exhibited an enantiomeric excess of (−)-α-pinene. Thus, chiral analysis provides useful information on the authenticity of pine EOs and allows to uncover possible mislabeling, the use of the wrong herbal substance and sources of adulteration in pine oil.

Quantitative Determination of Medazepam, Diazepam, and Nitrazepam in Whole Blood by Flame-Ionization Gas—liquid Chromatography

1974 ◽  
Vol 20 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Mavis S Greaves
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Whole Blood ◽  
Chromatographic Analysis ◽  
Gas Liquid Chromatography ◽  
Trimethylsilyl Derivative ◽  
Ionization Detector ◽  
Qualitative And Quantitative ◽  
Flame Ionization

Abstract Accurate methods are described for the qualitative and quantitative determination of medazepam, diazepam, and nitrazepam in 5 ml of whole blood. Medazepam and diazepam are analyzed intact and nitrazepam is chromatographed as its trimethylsilyl derivative by flame-ionization gas-chromatography on "1% OV-17." A supplementary column of "2% OV-1" is used to separate nitrazepam TMS from diazepam when both are present in the same extract. Essential data given include the percentage recovery of medazepam, and the flame-ionization detector responses of diazepam and silylated nitrazepam relative to medazepam, calculated after extraction from blood and gas-chromatographic analysis. Chromatograms are illustrated of extracts of blood taken from patients on medazepam and diazepam therapy and from a patient who had taken an overdose of nitrazepam.

Determination of Chlorobenzenes in Wastewater by Single-Drop Microextraction Coupled to Capillary Gas Chromatography

2013 ◽  
Vol 838-841 ◽  
pp. 2566-2569
Author(s):  
Jian Qi Sun ◽  
Bo Qiao ◽  
Jun Dai
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Preparation Technique ◽  
Single Drop ◽  
Flame Ionization ◽  
Single Drop Microextraction ◽  
Relative Standard ◽  
Efficient Recovery ◽  
Wastewater Samples

This study describes an analytical method employing capillary gas chromatography (GC) using flame ionization detection (FID) that has been developed for the simultaneous determination of chlorobenzenes (m-dichlorobenzene (m-DCB),p-dichlorobenzene (p-DCB),o-dichlorobenzene (o-DCB) and 1,2,4-trichlorobenzene (1,2,4-TCB)) in wastewater. For this purpose, single-drop microextraction (SDME) was applied as a sample preparation technique. The SDME parameters such as types of extractants, volume of the microdroplet size, extraction time, stir rate and immersion depth of needle point were studyed and optimized. The method was linear in the ranges from 4.0×10-3to 40.0 μg·mL-1form-DCB,p-DCB ando-DCB, and 4.0×10-3to 30.0 μg·mL-1for 1,2,4-TCB withR2≥0.9955. The SDME procedure allowed efficient recovery of the investigated chlorobenzenes ranging between 80 % and 105 % with a relative standard deviation (RSD) ≤6.5 for actual wastewater sampes spiked with 2, 5 and 10 μg·mL-1of chlorobenzes, respectively. These results showed the potential of this technique for chlorobenzenes monitoring in wastewater samples. Furthermore, the investigated methods are simple, reliable, reproducible, and not expensive.

scholarly journals GAS CHROMATOGRAPHIC ANALYSIS OF THE CHEMICAL COMPOSITION OF ETHYL ALCOHOL OBTAINED FROM PLANTS OF THE GENUS ASTERACEAE

2021 ◽  
Vol 2 (446) ◽  
pp. 6-13
Author(s):  
G.E. Azimbayeva ◽  
A.K. Kamysbayeva ◽  
Abdigali Bakibaev
Keyword(s):  
Gas Chromatography ◽  
Chemical Composition ◽  
Ethyl Alcohol ◽  
Chromatographic Analysis ◽  
Raw Materials ◽  
Jerusalem Artichoke ◽  
Chromatography Method ◽  
Impurity Composition ◽  
Plant Raw Materials ◽  
Gas Chromatographic Analysis

In recent years, serious attention has been paid around the world to the chemical and biotechnological processing of biomass of easily renewable plant raw materials. One of the most mass-produced aliphatic alcohols is ethyl alcohol. The aim of this work was gas chromatographic analysis of the chemical composition of ethyl alcohol obtained from plants of the genus Asteraceae (dahlia and jerusalem artichoke tubers, chicory and big burdock roots) growing on the territory of Kazakhstan. The article discusses the methods of obtaining and application of ethyl alcohol. The results of the analysis of the chemical composition of ethyl alcohol obtained from plants of the genus Asteraceae are presented. As a result of the study, alcohols were obtained in different concentrations. The chemical composition of ethyl alcohol was determined by gas chromatography. The impurity composition of ethyl alcohol obtained from various types of raw materials is also shown. The composition of impurities in various samples of ethanol and alcohol-containing products is considered in detail. The results of the study were discussed, and the peculiarities of using the gas chromatography method were shown.

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