SPOT TEST ANALYSIS OF PESTICIDES: DETECTION OF CARBARYL AND MANCOZEB IN WATER H. S. RATHORE, R. SHARMA andS. MITAL Department of Applied Chemistry, Z.H.College of Engineering and Technology, Aligarh Muslim University, Aligarh-202002, India (Received 30 July 1996; accepted 15 September 1996) Abstract. A new spot test is developed using sulphanilic acid-sodium nitrite-sodium hydroxide, 8-hydroxyquinoline and alkaline hexacyanoferrate (III) as colouring reagents for the sensitive and selective detection of carbaryl at g levels in environmental samples. A already know, spot test for dithiocarbamates, is extended for the selective detection of mancozeb at g levels in its formulations and water. Copper (II) chloride-acetic acid is used as a colouring reagent. Key words: carbaryl, environmental samples, formulations, fungicide, insecticide, mancozeb, spot test, water 1. Introduction In continuation to our previous work (Rathore et al., 1984; Rathore et al., 1989) now spot tests for carbaryl and for mancozeb have been developed. Carbaryl is used for insecticidal control in agriculture, forestry, poultry and pets. It shows predominantly contact action and it is weak cholinesterase inhibitor. Mancozeb is used to control broad range of plant diseases. It is a protective leaf-fungicide. Therefore, it is important to develop simple and inexpensive methods for their on-field detection and determination. This paper summarizes the results of detection of carbaryl and mancozeb in dust, sediments, soils, grains and water. 2. Experimental 2.1. APPARATUS Aluminium heating block, electric oven (Tempo, India), pH meter and conductivity bridge (Elico, India) were used. 2.2. CHEMICALS Carbaryl (5–10% dust) (Union Carbide, India), Mancozeb (75% WP) (Jaishree Agro Industries Pvt. Ltd., India), 8-hydroxyquinoline (BDH, England) were used. Water, Air, and Soil Pollution 97: 431–441, 1997. c 1997 Kluwer Academic Publishers. Printed in the Netherlands.