Range Grass 



The range grass plots varied from 5 to 320 acres in size. A Lawn-0- 

 King**^ — reel-type power mower, with a front-mounted catcher was used for 

 cutting samples from all plots. For aerial applications the transects (sam- 

 ples) were cut at right angles to the line of flight. Two or more ti^nsects, 

 depending on the size of the plots and the number of samples needed, were cut, 

 mixed together and held at 0°F. All samples were packed with dry ice and 

 shipped via air express and held in frozen condition until analyzed. 



INSECTICIDES ANALYZED 



The following insecticides were determined: aldrin; azinphosmethyl 

 (Guthion™ ; Bomyl^ (dimethyl 3-hydroxyglutaconate dimethyl phosphate) ; carbaryl 

 (Seviri^ ; diazinon; dieldrin; dimethoate; disulf oton; heptachlor; heptachlor 

 epoxide (1,4, 5, 6, 7, 8, 8-heptachloro-2,3-epoxy-3a,4,7,7a-tetirahydro-4^7-methano= 

 indan) ; naled (DibronP) ; phorate; toxaphene; and trichlorf on (Dylox^ , 

 Dieldrin and hsptachlor epoxide were not applied as such, but resulted from 

 the degradation of aldrin and heptachlor, respectively. 



LABORATORY PROCEDURES 



Prior to analysis the forage samples were cut into approximately 1-lnch 

 lengths by passing them through a lawn mower-type cutter. After cutting, the 

 samples were well mixed and suitable portions weighed out for analysis. 



Solvents were distilled in an all-glass apparatus before use, except the 

 reagent grade isopropyl alcohol which was used as received. 



Red Clover 



Aldrin and Dieldrin 



Three-hundred grams of red clover were tumbled with a 2-to-l mixture of 

 hexane and isopropyl alcohol and filtered, and the isopropyl alcohol was 

 removed by repealed washing with distilled water. The washed extract was 

 dried by filtration through anhydrous sodium sulfate. A portion of the 

 extract was concentrated to 35 ml. and chroma tographed through a hexane pre- 

 washed Attasol®-Hyf lo Super Cer^ (2:1) column. The aldrin was eluted from the 

 column with hexane and detennined by the method of O'Donnell and others (19) . 



An additional portion of the extract was concentrated and chroma tographed 

 through a hexane pre-washed column of a homogeneous mixture of e£ual amounts 

 of 60-mesh Florlsll®: magnesium oxide: Hyflo Super Cel: Columbia^ activated 

 carbon. The column was eluted with 95:5 hexane: ethyl ether. The dieldrin 

 content was measured by the method of either O'Donnall, Johnson and Weiss (20) 

 or Cueto (2) . In the samples analyzed by the method of Cueto, the eluate from 



Z/ Mention of a proprietary product in this publication does not consti- 

 tute a guarantee or warranty of the product by the U. S. Department of 

 Agriculture and does not imply its approval by the Department to the exclusion 

 of other products that may also be suitable, 



- 3 - 



