Rapid Semimicro Method for the Determination of Methyl Mercury in Fish Tissue

1972 ◽  
Vol 55 (3) ◽  
pp. 583-589 ◽  
Author(s):  
J F Uthe ◽  
J Solomon ◽  
B Grift
Keyword(s):  
Gas Chromatography ◽  
Thin Layer ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Aqueous Ethanol ◽  
Fish Tissue ◽  
Mercuric Iodide ◽  
Mercury In Fish ◽  
Layer Chromatography

Abstract A fast semimicro method for the determination of methyl mercury in fish tissue is described. The procedure involves extracting the methyl mercury into toluene as methyl mercuric bromide, partitioning the bromide into aqueous ethanol as a thiosulfate complex, and re-extracting into benzene as methyl mercuric iodide. Methyl mercury is quantitated with gas chromatography. The method is sensitive to 0.01 ppm. Recoveries of added methyl mercury were 99% and the presence of methyl mercury in the final extract was shown by thin layer chromatography and gas chromatography of the thin layer spot. A variety of mercurial compounds do not interfere in the analyses. The amounts of both methyl and total mercury found in a variety of tissues of aquatic animals are compared. The presence of a demethylase in seal is suggested by the findings of high levels of nonmethyl mercury. Additional cleanup by column chromatography on Florisil was necessary with certain samples. The gas chromatographic columns were kept operational by the intermittent injection of 3M potassium iodide. Due to column bleed and resulting detector contamination, the use of the easily cleaned concentric tube electron capture detector is recommended.

Quantitative Determination of Vitamin E Isomers using Gas Chromatography, High Performance Liquid Chromatography and High Performance Thin Layer Chromatography

2017 ◽  
Vol 54 (3) ◽  
pp. 294
Author(s):  
Hari Ramakrishnan K. ◽  
Janaky Ranjithkumar
Keyword(s):  
Gas Chromatography ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Vitamin E ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Highly Sensitive ◽  
Layer Chromatography

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.

Thin-Layer Chromatography for Chlorinated Pesticide Residue Analysis without Cleanup

1964 ◽  
Vol 47 (2) ◽  
pp. 306-310
Author(s):  
H V Morley ◽  
M Chiba
Keyword(s):  
Gas Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Plant Extracts ◽  
Residue Analysis ◽  
Rapid Screening ◽  
Pesticide Residue Analysis ◽  
Cleanup Procedure ◽  
Layer Chromatography

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.

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
Keyword(s):  
Gas Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Preparative Thin Layer Chromatography ◽  
Oxidation Products ◽  
Oxygen Analog ◽  
Oxidative Metabolites ◽  
Layer Chromatography

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.

Detection of Tricresyl Phosphates and Determination of Tri-o-Cresyl Phosphate in Edible Oils

1985 ◽  
Vol 68 (6) ◽  
pp. 1074-1076
Author(s):  
Mahishi N Krishnamurthy ◽  
S Rajalakshmi ◽  
Om Prakash Kapur
Keyword(s):  
Gas Chromatography ◽  
Thin Layer ◽  
Stationary Phase ◽  
Ethyl Acetate ◽  
Edible Oils ◽  
Flame Ionization Detection ◽  
Tricresyl Phosphate ◽  
Flame Ionization ◽  
Layer Chromatography

Abstract Tricresyl phosphate (TCP) in contaminated edible oils was extracted using acetonitrile and detected by thin layer chromatography as well as gas chromatography (GC). The chromatoplate was developed with isooctane-ethyl acetate (90 + 10) and visualized by spraying with 2,6- dichloroquinone chloroimide. TCP gives a characteristic blue-violet spot when heated at 100°C for 15 min. The method is direct and sensitive and can be used to detect as low as 2.5 p.g TCP or TOCP (tri-o-cresyl phosphate). GC was carried out using 10% OV-101 as the stationary phase and flame ionization detection for confirmation and quantitation of TOCP in oils.

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