Radioisotope techniques have been used to study the breakdown products that are formed from the herbicide cyanazine (BLADEX)", 2-chIoro-4-( 1 -cyano-Imethylethyl-amino)-6-ethylamino-l,3,5-triazine, in soils and in maize grown in the soils under indoor conditions.In soils of different types cyanazine broke down mainly by conversion of the nitrile group to amide (11) and then to an acid (111) followed by hydrolysis of the ring chlorine to hydroxyl (IV). Dealkylation reactions occurred to only a limited extent in soils.In maize plants grown in treated soils the hydrolysis products, the amide (U) and the hydroxy acid (IV) were detected as well as appreciable quantities of products (VI) and (VIU) formed from these by loss of the N-ethyl group. In plants the hydroxy acids (IV) and (VIII) were present in the free form and there was also evidence for conjugates which were not identified but could beconverted to these hydroxy acids, (IV) and (VIM), on treatment with acids.

1. The major metabolic transformation of orally ingested 14C-DGEBPA is by hydrolytic ring-opening of the two epoxide rings to form diols. This metabolite (the bis-diol of DGEBPA) is excreted in both free and conjugated forms and is further metabolized to various carboxylic acids, including two containing a methylsulphonyl moiety. 2. The product of oxidative dealkylation either of DGEBPA (with concomitant formation of glycidaldehyde) or of the bis-diol of DGEBPA (with concomitant formation of glyceraldehyde) is excreted in both free and conjugated forms in amounts representing 5% of the dose. 3. The high activity of epoxide hydratase towards DGEBPA suggests that glyceraldehyde and not glycidaldehyde is formed in vivo. 4. Hepatic epoxide hydratase activity towards DGEBPA measured in vitro decreased in the order rabbit greater than mouse greater than rat. 5. Two discrete epoxide hydratases are present in large amounts in the mouse. One is membrane-bound in the liver microsomal fraction and the other is a "soluble' enzyme located in the liver cytosol. This cytosolic enzyme was present in only very small amounts in the rat.

The degradation in soil of the major constituents of a 1,3-dichloropropenel,2-dichloropropane nematicide has been studied under laboratory and outdoor conditions. In sealed glass containers, ( Z ) -and (E)-1,3-di~hloropene-2-~~C were converted in soil into the corresponding 3-chloroallyl alcohols and these alcohols were in part strongly bound to the soil. The (Z)and (E)-3-chloroacrylic acids were also found as minor products. More polar products were detected and these released the chloroacrylic acids in 20-30 % yield upon hydrolysis. Although the 1,3-dichloropropenes were lost by volatilisation from soil stored in open glass jars outdoors, they also underwent degradation to the same products that were detected in sealed containers. There was evidence of only slight degradation of 1,2-dichloropropane-2-14C (4% or less of the applied radioactivity remained unextracted from a loam soil after 5 months). When soil treated with the 1,2-dichloropropane was stored outdoors in an open glass container, less than 1 % of the original radiolabel remained in the soil after 10 days under these conditions due to volatilisation of the applied material. In a separate experiment potatoes were grown in soil 6 months after treatment with a mixture of both ( Z ) -and (E)-l,3-dichloropropene-2-W and 1,2-dichloropropane-2-1 4 C . Although 5% of the applied radiolabel remained in the soil at potato harvest the potato tubers contained only a very small residue (0.007 mg/kg).

1. 14C-DGEBPA dermally applied to mice was only slowly eliminated in the feces (20% dose) and urine (3%), as a mixture of metabolites, over three days. Most of the applied radioactivity (66% dose) was extracted from the application area and its covering foil. 2. When 14C-DGEBPA was given orally to mice it was rapidly excreted; 80% of the administered 14C was eliminated in the feces and 11% in the urine 0-3 days after a single oral dose. 3. The urinary faecal metabolite profiles derived from dermal application and oral dosing were essentially similar.

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