scholarly journals STUDIES ON TRICHLOROETHYLENE METABOLITES IN URINE : PART I. SIMPLIFICATION FOR THE DETERMINATION OF SO-CALLED FUJIWARA-REACTION-POSITEVE METABOLITES

Sangyo Igaku ◽  
1960 ◽  
Vol 2 (6) ◽  
pp. 466-471
Author(s):  
Kaoru OHMORI
Keyword(s):  
Fujiwara Reaction

scholarly journals Determination of rate constants for formation and decomposition of color products in the Fujiwara reaction using benzotrichloride.

1984 ◽  
Vol 32 (1) ◽  
pp. 174-178 ◽  
Author(s):  
KAZUO OKUMURA ◽  
TOSHIKO WADA ◽  
KIYOSHI YAMAOKA ◽  
TOYOZO UNO
Keyword(s):  
Rate Constants ◽  
Fujiwara Reaction

An improved procedure for application of the Fujiwara reaction in the determination of organic halides

The Analyst ◽  
1974 ◽  
Vol 99 (1183) ◽  
pp. 652 ◽  
Author(s):  
J. F. Reith ◽  
W. C. van Ditmarsch ◽  
Th. de Ruiter
Keyword(s):  
Organic Halides ◽  
Fujiwara Reaction

An Extractive Spectrophotometric Method for the Determination of Pymetrozine in Various Ecological Samples of Bilaspur District (C.G.)

2020 ◽  
Vol 33 (1) ◽  
pp. 65-72
Author(s):  
Jyoti Goswami ◽  
Thakur Vikram Singh ◽  
Chhaya Bhatt ◽  
Deepak Kumar Sahu ◽  
Kalpana Wani ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Schiff’S Base ◽  
Yellow Color ◽  
Beer's Law ◽  
Violet Color ◽  
Beer’S Law ◽  
Fujiwara Reaction

Pesticides are designated mixture of substances for extenuating and destroying any group of pests such as insects and vegetation. Pymetrozine [6-methyl-4-[(E)-pyridin-3-ylmethylideneamino]-2, 5-dihydro-1, 2, 4-triazin-3-one] is a pyridine azomethine compound which represents a class of insecticide. A Spectrophotometric method has been developed on the modified Fujiwara reaction for the determination of pymetrozine. Pymetrozine directly reacts with chloroform the 45-500C turns out the violet color in the formation of Schiff’s Base (Glutaconic Aldehyde). In the present reaction, the violet color obtained is discharged with a few drops of acetic acid followed by the addition of p- nitro aniline reagent which gives yellow color dyes. The absorption maxima of yellow-colored dye measured at 430 nm. Beer’s law is obeyed over the range of 1 to 10 µg per 10 ml of pymetrozine. The molar absorptivity of the colored system is 1.38×105 L mol-1 and Sandall’s sensitivity is 1.0×10-3µg cm-2. This method is free from the interference of other interfering and can be successfully applied for the determination of various ecological samples.

Determination of Dicofol (Kelthane®) Residues in Fruits and Vegetables

1968 ◽  
Vol 51 (4) ◽  
pp. 899-900
Author(s):  
Ellis L Gunderson
Keyword(s):  
Formic Acid ◽  
Fruits And Vegetables ◽  
Colorimetric Method ◽  
Chlorinated Pesticides ◽  
Fujiwara Reaction

Abstract A colorimetric method for the determination of dicofol residues involves the extraction and cleanup procedures of the Mills, Onley, and Gaither method for chlorinated pesticides, with modification of the Florisil cleanup step. The determinative step is a modified Fujiwara alkaline pyridine reaction. The product of the Fujiwara reaction is treated with benzidine in formic acid, and the resulting colored solution is analyzed spectrophotometrically at 530 mμ. The method will detect as little as 5 μg dicofol and has been employed successfully in analysis of various fruits and vegetables, with recoveries of 93—100% at levels of 1, 2, and 5 ppm. Cleanup on all crops tested was adequate. It is recommended that studies on the method be continued, and that the method be studied collaboratively

Modified Fujiwara reaction for the determination of trichloroacetic acid

1991 ◽  
Vol 43 (2) ◽  
pp. 109-111 ◽  
Author(s):  
Madhusri Bhattacharjee ◽  
Lata Cherian ◽  
V.K. Gupta
Keyword(s):  
Trichloroacetic Acid ◽  
Fujiwara Reaction
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