Health & Environmental Research Online (HERO)


Print Feedback Export to File
1815189 
Technical Report 
Photolysis of pesticidal synergists. I. Piperonyl butoxide 
Fishbein, L; Gaibel, ZLF 
1970 
HAPAB/71/01004 
Environ 
6 
HAPAB The stability of piperonyl butoxide under a variety of photolysis conditions was studied. Technical grade piperonyl butoxide in open Pyrex crystallizing dishes in an environmental ,weathering chamber' was irradiated for 7 days with a 275 W General Electric Sunlamp. The lamp was 22.54 cm from the test compound. The photochemical activating light level intensity was 8,500,000 ergs/sq cm/sec. A Kettering YSI Model 65 radiometer with a fused quartz window probe made the measurements. The exposure temperature was 53 C. Other test samples were irradiated in 500 ml of water-cooled, photochemical borosilicate and in quartz immersion wells by means of a Hanovia 450 W mercury lamp with or without filters or irradiated in outdoor sunlight in Pyrex crystallizing dishes. Similar tests were carried out with unirradiated controls. Photochemical products were examined by thin-layer (TLC) and gas-liquid chromatography (GLC). Concentrated samples were examined by TLC using silica gel GF. The developers were 2:1:1 chloroform acetic acid-water and 6:1:2 n-butanol-acetic acid-water mixtures. Solutions of 1% of aqueous ferric chloride-potassium ferricyanide and 1% aqueous p-phenylenediamine served as detecting agents. Other TLC assays were carried out using silica gel G with 2.5% acetone in benzene and 90:10 butanol-water (developing solvents) and chromatrophic sulfuric acid spray, silver nitrate-2-phenoxy ethanol and benzidine-periodate (chromatogenic reagents). GLC analyses were performed on an F and M 700-1099F Laboratory Chromatograph equipped with a Hewlett-Packard Model 240 temperature programmer, flame ionization detector and stainless steel columns packed with 4% QF-1 or 3% Carbowax 20M on 80/100 mesh HMDS Chromosorb W. Piperonyl butoxide was found to be stable under all the conditions tested. Ninety-five percent (by weight) of the test compound irradiated in a weathering chamber was recovered after the 7-day test period. From 96 to 98% of the piperonyl butoxide (by weight) exposed to sunlight was recovered as unreacted mother compound. A dark brown product, a polymeric, accounted for from 1.5 to 3% of the recovered material. 1970