Investigation on Determination and Confirmation of Dyrene Added to Plant Extracts: GLC and TLC of Dyrene and Products of Its Reaction in Methanolic Sodium Hydroxide

1970 ◽  
Vol 53 (3) ◽  
pp. 509-513
Author(s):  
P J Wales ◽  
C E Mendoza
Keyword(s):  
Thin Layer ◽  
Silver Nitrate ◽  
Sodium Hydroxide ◽  
Enzyme Inhibition ◽  
Electron Capture ◽  
Plant Extracts ◽  
Uv Light ◽  
Parent Compound ◽  
Spray Reagent ◽  
Qualitative Confirmation

Abstract As determined by electron capture GLC, recoveries of Dyrene from strawberries, potatoes, tomatoes, and cucumber samples, using an acetonitrile extraction-hexane partition procedure, were more than 80%. TLC was used for qualitative confirmation. The possible interference in the GLC and TLC analyses from selected pesticides was investigated. Treatment with methanolic sodium hydroxide converted Dyrene to 2 major products with longer GLC retention times and slower TLC migrat i on rates than the parent compound. Dyrene and the products were visualized on thin layer plates by using a silver nitrate spray reagent or by viewing induced fluorescence under UV light. The products were also detected by an enzyme inhibition procedure.

Sodium Methylate Treatment of Cleaned Up Plant Extracts in Confirmation of Some Pesticide Residues By Gas-Liquid and Thin Layer Chromatography

1968 ◽  
Vol 51 (5) ◽  
pp. 1095-1101
Author(s):  
C E Mendoza ◽  
P J Wales ◽  
H A Mcleod ◽  
W P Mckinley
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Plant Extracts ◽  
Pesticide Residues ◽  
Sodium Methylate ◽  
Heptachlor Epoxide ◽  
Rapid Procedure ◽  
Qualitative Confirmation ◽  
Layer Chromatography

Abstract A rapid procedure that involves GLC-EC and TLC analyses of plant extracts 5 min after treatment with sodium methylate is described for the qualitative confirmation of some pesticide residues. Plant extracts are cleaned up by elution through a carboncellulose column before treatment. The compounds studied were aldrin, captan, carbophenothion, p,p'-DDD, de-hydrochlorinated p,p-DDD, p,p'-DDE, o,p -DDT, p,p -DDT, Diazinon, dieldrin, disulfoton, heptachlor, heptachlor epoxide, malathion, methoxychlor, de-hydrochlorinated methoxychlor, mevinphos, and parathion. The pesticides added to beet, lettuce, pineapple, potato, and wheat eluates were reliably confirmed by GLC-EC or TLC after sodium methylate treatment. The procedure could be used to confirm only some of the pesticides added to extracts of apples, carrots, cauliflower, grapes, and peas because of components in these samples that gave interfering peaks

scholarly journals A Molecular Boron Cluster-Based Chromophore with Dual Emission

2020 ◽  
Author(s):  
Kierstyn P. Anderson ◽  
Mary A. Waddington ◽  
Gary J. Balaich ◽  
Julia M. Stauber ◽  
Justin R. Caram ◽  
...  
Keyword(s):  
Signal Intensity ◽  
Electrophilic Substitution ◽  
Uv Light ◽  
Parent Compound ◽  
Crystalline Solid ◽  
Oxygen Probe ◽  
Dual Emission ◽  
Fluorescent Signal ◽  
Boron Cluster ◽  
Monosubstituted Derivative

Bromination of the luminescent borane, anti-B18H22, via electrophilic substitution using AlCl3 and Br2 yields the monosubstituted derivative 4-Br-anti-B18H21 as an air-stable crystalline solid. In contrast to the unsubstituted parent compound, 4-Br-anti-B18H21 product possesses dual emission upon excitation with UV light and exhibits fluorescence at 410 nm and phosphorescence at 503 nm, with Фtotal = 0.07 in oxygen-free cyclohexane. Increased oxygen content in cyclohexane solution quenches the phosphorescence signal. The fluorescent signal intensity remains unaffected by oxygen, suggesting that this molecule could be used as a ratiometric oxygen probe.

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.

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