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1552656 
Journal Article 
A simple and robust method for determination of neem (Azadirachta indica A. Juss) oil in neem oil coated urea 
Kumar, R; Devakumar, C; Kumar, R; Gupta, AK 
2012 
1 
Toxicological and Environmental Chemistry
ISSN: 0277-2248
EISSN: 1029-0486 
94 
4 
641-649 
WOS:000304275200001 
The production of neem oil coated urea (NOCU), a technology
developed by the Indian Agricultural Research Institute, has been grown to over 2.0 million tons
per year. The estimation of neem oil content in NOCU is important due to its significance in
ensuring agronomic efficiency. Therefore, this study was taken up to develop a simple method for
the determination of neem oil in NOCU. The procedure involves extraction of neem oil from NOCU;
saponification of extracted oil; oxidation of released glycerol to formaldehyde, and subsequent
conversion of formaldehyde to a dihydrolutidine derivative. Its concentration was determined
spectrophotometrically. The recoveries of neem oil from NOCU with oil load of 500 and 1000 ppm
were 87.6 +/- 3.0% and 90.0 +/- 4.8% respectively with direct method; and improved to 92.6 +/-
4.0% and 96.7 +/- 3.8% after including the in situ purification. A simple method based on the
Hantzsch reaction was developed for the determination of neem oil in NOCU. This method is
superior to earlier methods in terms of sensitivity, simplicity, and time required. 
Hantzsch reaction; neem oil coated urea; UV-Vis spectroscopy; analytical method