Determination of Oxidative Metabolites of Dimethoate and Thimet in Soil by Emission Spectroscopic Gas Chromatography

1966 ◽  
Vol 49 (3) ◽  
pp. 647-650
Author(s):  
C A Bache ◽  
D J Lisk

Abstract The conversion of dimethoate to its oxygen analog and the production of oxidative metabolites of Thimet in soil has been shown by using emission spectroscopic gas chromatography for their determination. Preparative thin layer chromatography was vised for prior separation of Thimet oxidation products. The sulfoxide and sulfone of Thimet were the major determinable products.

2017 ◽  
Vol 54 (3) ◽  
pp. 294
Author(s):  
Hari Ramakrishnan K. ◽  
Janaky Ranjithkumar

Vitamin E, the fat soluble vitamin is present naturally in some foods and added in food supplements, nutraceuticals etc due to its vital biological function as an antioxidant. Various methods are available for the analysis of vitamin E. Especially High Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC) are exclusively used for the quantitative evaluation of vitamin E, which has also identified the four different isomeric forms of this vitamin. The rate of losses of this vitamin during food processing and analysis, in addition to their transient dynamics, presents complexities in developing a highly sensitive procedure for their separations. Though effective, HPLC instrument is expensive and comparatively cumbersome. In this prospective, the study was to evaluate the usefulness of High Performance Thin Layer Chromatography (HPTLC) in the analysis of vitamin E. There are methods available using Thin Layer Chromatography for its analysis, but they are not sensitive enough to identify the isomeric forms of vitamin E. In this HPTLC method, the different isomeric forms of vitamin E - α, β, γ and δ were identified. This technique shall be considered as an alternative to the other methods such as HPLC and GC.


1964 ◽  
Vol 47 (2) ◽  
pp. 306-310
Author(s):  
H V Morley ◽  
M Chiba

Abstract Thin-layer chromatography on silica gel may be used for the determination of chlorinated pesticide residues in some plant extracts without prior cleanup, thus eliminating the possible loss of pesticides during the cleanup procedure. Rapid screening of a large number of samples is thus possible with consequent saving of time and labor. When necessary, thin-layer chromatography may be used as a prior cleanup for gas chromatography.


1967 ◽  
Vol 50 (4) ◽  
pp. 934-938
Author(s):  
Paul E Corneliussen

Abstract A rapid method for determining biphenyl in citrus fruits has been developed and was studied collaboratively. Biphenyl is separated from fruit tissue by steam liquidliquid extraction. The ra-heptane extract is subjected to preparative thin layer chromatography (TLC) on plates coated with silica gel containing phosphors for ready visibility of the biphenyl spots under UV light. The spots are removed from the plate and extracted with alcohol for spectrophotometric measurement at 248 mμ. The TLC cleanup adds specificity to the method; o-phenylphenol, if present, does not interfere and crop blanks are insignificant. The average of 36 recoveries (12 each at abovit 100, 50, and 10 ppm) was 96.7% with a mean deviation of 10.7%. It is recommended that the method be adopted as official, first action.


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