Application of a random forests (RF) method as a new approach for variable selection and modelling in a QSRR study to predict the relative retention time of some polybrominated diphenylethers (PBDEs)

2012 ◽  
Vol 4 (11) ◽  
pp. 3733 ◽  
Author(s):  
Nasser Goudarzi ◽  
Davood Shahsavani
Keyword(s):  
Variable Selection ◽  
Random Forests ◽  
Retention Time ◽  
Relative Retention Time ◽  
New Approach ◽  
Relative Retention ◽  
Polybrominated Diphenylethers

2,2-Dialkylacetic Acids -A New Class of Naturally Occurring Lipid Constituents

1995 ◽  
Vol 50 (1-2) ◽  
pp. 123-126 ◽  
Author(s):  
Gottfried Raab ◽  
Jürgen Jacob
Keyword(s):  
Retention Time ◽  
Relative Retention Time ◽  
Methyl Esters ◽  
South American ◽  
Time Data ◽  
New Class ◽  
The Past ◽  
Relative Retention ◽  
Naturally Occurring ◽  
Acetic Acids

Abstract The uropygial gland waxes of the South American red-legged Seriema (Cariama cristata (L., 1766)) were found to be composed of unbranched alcohols and 2,2′-dialkyl-substituted acetic acids which so far have not been found in skin lipids. When used as a chemosystematic character, the occurrence of this lipid class separates the order Cariamiformes (Seriemas) from all other avian orders hitherto investigated, especially from the Gruiformes (cranes and rails) to which they have been tentatively attributed in the past. From the GC retention time data now available for a series of 2-alkyl-substituted fatty acid methyl esters relative retention time indices for other compounds may be predicted.

Capillary Gas Chromatographic Separation of Various Stimulants

1985 ◽  
Vol 68 (4) ◽  
pp. 809-810
Author(s):  
Devendra Trivedi
Keyword(s):  
Retention Time ◽  
Chromatographic Separation ◽  
Relative Retention Time ◽  
Reference Standard ◽  
Relative Retention ◽  
Gas Chromatographic Separation

Abstract A capillary gas chromatographic (GC) method was developed for the separation of various stimulants of forensic and pharmaceutical interest. The data consist of retention time, relative retention time, corrected retention time, and relative corrected retention time, calculated using ephedrine as reference standard.

Study on the diagram of relative retention time for organophosphorus pesticides by gas chromatography.

Eisei kagaku ◽  
1988 ◽  
Vol 34 (3) ◽  
pp. 282-290 ◽  
Author(s):  
MASAMI OMURA ◽  
KUMIKO HASHIMOTO ◽  
KUNIO OHTA ◽  
KAZUO SHINJI ◽  
KEIKO ANDO ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Retention Time ◽  
Relative Retention Time ◽  
Organophosphorus Pesticides ◽  
Relative Retention

QSPR study on GC relative retention time of organic pesticides on different chromatographic columns

2008 ◽  
Vol 31 (13) ◽  
pp. 2434-2443 ◽  
Author(s):  
Ruzhu Hu ◽  
Chunsheng Yin ◽  
Yang Wang ◽  
Chunhui Lu ◽  
Tiefei Ge
Keyword(s):  
Retention Time ◽  
Relative Retention Time ◽  
Relative Retention ◽  
Chromatographic Columns ◽  
Qspr Study ◽  
Organic Pesticides

Effective application of the relative retention time diagram for gas chromatographic analysis of pesticides

1991 ◽  
Vol 39 (12) ◽  
pp. 2200-2205 ◽  
Author(s):  
Masami Omura ◽  
Kumiko Hashimoto ◽  
Kunio Ohta ◽  
Tomoyuki Iio ◽  
Shigekazu Ueda ◽  
...  
Keyword(s):  
Retention Time ◽  
Chromatographic Analysis ◽  
Relative Retention Time ◽  
Time Diagram ◽  
Effective Application ◽  
Gas Chromatographic Analysis ◽  
Relative Retention

Behavior of 78 Pesticides and Pesticide Metabolites on Four Different Ultra-Bond Gas Chromatographic Columns

1987 ◽  
Vol 70 (6) ◽  
pp. 1014-1017
Author(s):  
John F Suprock ◽  
Howard J Vinopal
Keyword(s):  
Retention Time ◽  
Relative Retention Time ◽  
Mixed Phase ◽  
Elution Order ◽  
Organophosphorus Insecticides ◽  
Time Data ◽  
Relative Retention ◽  
Pesticide Metabolites ◽  
Different Types ◽  
Dual Column

Abstract The gas chromatographic (GC) elution order and relative retention time data (compared to aldrin) are presented for 78 pesticides and pesticide metabolites on 4 different types of commercially available 2 mm id ultra-Bond columns including ultra-Bond 20M (20M), Ultra-Bond 20SE (20SE), Ultra-Bond 20M coated with 1% OV-210 (OV-210), and ultra-Bond 20M coated with 0.5% OV-210 + 0.65% OV-17 (mixed phase). Relative retention time data (compared to parathion) are also represented for 19 organophosphorus insecticides on the 4 ultra-Bond columns evaluated. Corresponding 4 mm id Ultra-Bond columns were evaluated at the same time as the 2 mm id columns, and results and comparisons for these larger-diameter columns are discussed. These data indicate that, with aldrin as a reference peak, a complement of the mixed-phase column and either the 20M, the 20SE, or the OV-210 column represents a useful chromatographic tool for dual-column analysis of pesticide residues. The 2 mm id columns were more useful in chromatographing later-eluting pesticides whereas the corresponding 4 mm id columns were more useful in chromatographing earlier-eluting pesticides.

scholarly journals Evidence for a Chromatographic Model of Olfaction

1970 ◽  
Vol 56 (1) ◽  
pp. 46-63 ◽  
Author(s):  
Maxwell Mark Mozell
Keyword(s):  
Retention Time ◽  
Relative Retention Time ◽  
Olfactory Nerve ◽  
General Level ◽  
Medial Branch ◽  
Gas Chromatograph ◽  
Flow Rates ◽  
Relative Retention ◽  
Chromatographic Process ◽  
Small Change

The gradient of activity produced along the olfactory mucosa by odorant stimulation was measured by the ratio (the LB/MB ratio) of the summated neural discharges recorded from two branches of the olfactory nerve, a lateral branch (LB) supplying a mucosal region near the internal naris and a medial branch (MB) supplying a region near the external naris. Twenty-four frogs "sniffed" sixteen different odorants, each odorant at four concentrations and two flow rates. Increases in concentration and flow rate produced statistically reliable increases in the ratios; the magnitude of these increases was considerably smaller than the magnitude of the statistically significant changes that could be achieved by shifting the odorants themselves. Even the small change due to concentration depended upon the odorant presented. Thus, even at the highest physiologically possible concentrations and flow rates, the general level of the activity gradient along the mucosa appeared to be determined mainly by the particular odorant used. The relative retention time of each of these 16 different odorants was measured in a gas chromatograph fitted with a Carbowax 20M column. In general, the longer the odorant's retention time the smaller its LB/MB ratio. This suggests that the different mucosal gradients of activity are established for different odorants by a chromatographic process. The data further suggest that the mucosa behaves like a polar chromatographic column.

Retention Time Data for Organochlorine, Organophosphorus, and Organonitrogen Pesticides on SE-30 Capillary Column and Application of Capillary Gas Chromatography to Pesticide Residue Analysis

1983 ◽  
Vol 66 (5) ◽  
pp. 1084-1095
Author(s):  
Brian D Ripley ◽  
Heinz E Braun
Keyword(s):  
Pesticide Residue ◽  
Retention Time ◽  
Relative Retention Time ◽  
Residue Analysis ◽  
Pesticide Residue Analysis ◽  
Time Data ◽  
Relative Retention ◽  
Single Temperature ◽  
Organonitrogen Pesticides ◽  
Temperature Programmed

Abstract Relative retention time data for 194 pesticides and metabolites are reported for a 15 m SE-30 capillary gas chromatographic column under a single temperature programmed regime. The reproducibility of retention time and quantitation is discussed and the performance of electron capture and nitrogenphosphorus thermionic detectors is evaluated in relation to pesticide residue analysis.

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