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C 112#$D  3 tust&'3X!u!u !u!u!u !u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u12#$D  3 tust&'3XR"8P$ Unknown Eric BechtelZk$#%\^ Eric Bechtel?Macintosh HD:AE Newsletters:November98:Articles:EDITED Skidmore Eric Bechtel<Macintosh HD:Temporary Items:AutoRecovery save of EDITED Ski Eric Bechtel<Macintosh HD:Temporary Items:AutoRecovery save of EDITED Ski Eric Bechtel?Macintosh HD:AE Newsletters:November98:Articles:EDITED Skidmore Eric Bechtel/Macintosh HD:Tempor [4@4NormalCJOJPJQJmH <A@<Default Paragraph Font'J!  C '1|12#$D  3 tust)!u!u !u!u!u !u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u!u3 tust)F"8=$ Unknown Eric BechtelZk$%%)$&) Eric Bechtel?Macintosh HD:AE Newsletters:November98:Articles:EDITED Skidmore Eric Bechtel<Macintosh HD:Temporary Items:AutoRecovery save of EDITED Ski Eric Bechtel?Macintosh HD:AE Newsletters:November98:Articles:EDITED Skidmore Eric Bechtel<Macintosh HD:Temporary Items:AutoRecovery save of EDITED Ski Eric Bechtel<Macintosh HD:Temporary Items:AutoRecovery save of EDITED Ski Eric Bechtel?Macintosh HD:AE Newsletters:November98:Articles:EDITED Skidmore Eric Bechtel/Macintosh HD:Temporary Items:Word Work File A 1 Eric Bechtel/Macintosh HD:Temporary Items:Word Work File A 1 Eric Bechtel/Macintosh HD:Temporary Items:Word Work File A 1 Eric Bechtel?Macintosh HD:AE Newsletters:R"8P$ Unknown Eric BechtelZk $#%\^ Eric Bechtel?Macintosh HD:AE Newsletters:November98:Articles:EDITED Skidmore Eric Bechtel<Macintosh HD:Temporary Items:AutoRecovery save of EDITED Ski Eric Bechtel<Macintosh HD:Temporary Items:AutoRecovery save of EDITED Ski Eric Bechtel?Macintosh HD:AE Newsletters:November98:Articles:EDITED Skidmore Eric Bechtel/Macintosh HD:Temporary Items:Word Work File A 1 Eric Bechtel/Macintosh HD:Temporary Items:Word Work File A 1 Eric Bechtel/Macintosh HD:Temporary Items:Word Work File A 1 Eric Bechtel?Macintosh HD:AE Newsletters:November98:Articles:EDITED Skidmore Eric Bechtel/Macintosh HD:Temporary Items:Word Work File A 2 Eric Bechtel?Macintosh HD:AE Newsletters:November98:Articles:EDITED Skidmore @X%5 6t(#()ABC$45BCy~YZo)   * L m s { | 7 : ; + , O P d ; Z j Xstu|}7FGSYZf  *+1`frt'Q;@NPSTWw/235 %"#%X1@101 00P@121. @1"21B21D21 @1f21 @101$ @1&1j21l21Z&121~ @1^&120X @11&1"120~@121216@121n@11&11j1&121j10<0@1&131131111$1(11131131131141311P31R3181|111311j1~1P1V1X1v 1 '1:!131!131"130"1#1"'1~'1'1$(131(1(1^*0*0*1*1*131*1+1,1,1,1h-1-1.1318.0.0.1.131/1/040B41414141 51N61P61~6161616161 70"71&7081818191(:1@:1:1:1$;1<1<1=1=1"=1(=1*=10=0p=0=1?1 @1>@1@1xB1zB1B1B1B1C1.D16F1vF1F0J1J1J0K1"M1$M0 N1N1N0N0N0P0P1R1F0@GTimes New Roman5Symbol3 Arial3Times"1hc*&Lk*F .$0dz@0Metabolism of Pesticides in Plants and Livestock Eric Bechtel Eric Bechtel0d`@0Metabolism of Pesticides in Pl FMicrosoft Word DocumentNB6WWord.Document.8Version8.0TT& ՜.+,D՜.+,< hp  '%FEQL/PIC Washington State Universityes. z: 1Metabolism of Pesticides in Plants and Livestock Title November98:Articles:EDITED Skidmore @%%X% 5 6(#()ABC$45BCy~YZo)   * L m s { | 7 : ; + , O P d ; Z j Xstu|}7FGSYZf  *+1`frt'Q;@NPSTWw/235 %&'1@101 00P@121. @1"21B21D21 @1f21 @101$ @1&1j21l21Z&121~ @1^&120X @11&1"120~@121216@121n@11&11j1&121j10<0@1&131131111$1(11131131131141311P31R3181|111311j1~1P1V1X1v 1 '1:!131!131"130"1#1"'1~'1'1$(131(1(1^*0*0*1*1*131*1+1,1,1,1h-1-1.1318.0.0.1.131/1/040B41414141 51N61P61~6161616161 70"71&7081818191(:1@:1:1:1$;1<1<1=1=1"=1(=1*=10=0p=0=1?1 @1>@1@1xB1zB1B1B1B1C1.D16F1vF1F1F0@GTimes New Roman5Symbol3 Arial3Times"1hc*&9k*F .$0dz@0Metabolism of Pesticides in Plants and Livestock Eric Bechtel Eric Bechtelm of Pesticides in Plants and Livestock The use of pesticides to control pests and disease is important for the production of sufficient quantities of safe and affordable food. However, the use of these agents sometimes leaves residues (the pesticide or its degradates) in/on plant parts used as human food or animal feed commodities. These residues may enter the human food chain either directlythrough the consumption of treated foods, e.g. grain or fruit, or indirectlythrough the transfer of resiary Items:Word Work File A 1 Eric Bechtel/Macintosh HD:Temporary Items:Word Work File A 1 Eric Bechtel/Macintosh HD:Temporary Items:Word Work File A 1 Eric Bechtel?Macintosh HD:AE Newsletters:November98:Articles:EDITED Skidmore Eric Bechtel/Macintosh HD:Temporary Items:Word Work File A 2 Eric Bechtel?Macintosh HD:AE Newsletters:November98:Articles:EDITED Skidmore @X5 6t(#()ABC$45BCy~YZo)   * L m s { | 7 : ; + , O P d ; Z j Xstu|}7FGSYZf  *+1`frt'Q;@NPSTWw/235 %"#%Xdiolabeled materials facilitates monitoring of the distribution of the residue throughout the system and provides an estimate of the total residue. By linking radioactive detection with chromatographic separation systems and spectral analysis, the individual components of the residue can be isolated, characterized, and identified. From this information, the fate of the compound in the test system (i.e., the biotransformation pathway) can be defined. How the data are used Once the amount of the total radioactive residues has been determined and the structures of the major metabolites are known, the toxicological significance of the residues can be assessed. If the plant metabolism data indicate that the metabolites formed are both qualitatively and quantitat1@101 00P@121. @1"21B21D21 @1f21 @101$ @1&1j21l21Z&121~ @1^&120X @11&1"120~@121216@121n@11&11j1&121j10<0@1&131131111$1(11131131131141311P31R3181|111311j1~1P1V1X1v 1 '1:!131!131"130"1#1"'1~'1'1$(131(1(1^*0*0*1*1*131*1+1,1,1,1h-1-1.1318.0.0.1.131/1/040B41414141 51N61P61~6161616161 70"71&7081818191(:1@:1:1:1$;1<1<1=1=1"=1(=1*=10=0p=0=1?1 @1>@1@1xB1zB1B1B1B1C1.D16F1vF1F0J1J1J0K1"M1$M0 N1N1N0N0N0P0P1R1F0@GTimes New Roman5Symbol3 Arial3Times"qhc*&Lk*F  .$20dz@0Metabolism of Pesticides in Plants and Livestock Eric Bechtel Eric Bechtel1R3181|111311j1~1P1V1X1v 1 '1:!131!131"130"1#1"'1 FMicrosoft Word DocumentNB6WWord.Document.8Version8.0TT& ՜.+,D՜.+,< hp  '%FEQL/PIC Washington State Universityes. z: 1Metabolism of Pesticides in Plants and Livestock Title 6> _PID_GUID'AN{978AE400-61E6-11D2-8F75-C17FF64FD95A}000-C000-000000000046}Ve Oh+'0  $0 L X dpx'1Metabolism of Pesticides in Plants and LivestockPleta Eric Bechtel PericNormalc Eric Bechtel Pe9icMicrosoft Word 8.0c@<@ZE@f Pesticides in Plants and Livestock Eric Bechtel Eric Bechtel 12 ?@!u!u !u!u!u!u@ver if the use pattern of the pesticide targets other species than studies would be carried out accordingly. Metabolism studies are carried out in representative species from these groups; usually lactating goats or cows and laying hens are the species of choice. Treatment is carried out to closely approximate expected exposure. (a) For ingested residues oral dosing is usually carried out over a period of several days to allow the residues in tissues, milk, and eggs to reach a steady state. The dosing (test) material should reflect the major component of the terminal residue in treated crops. This is frequently the parent compound, however where the parent is not the major component of the residue the test material may consist of a single metabolite, a synthetic mixture of metabolites or plant material resulting from the metabolism studies. (b) For dermal applications, the radiolabelled chemical is applied, formulated, in a way that reflects the proposed use pattern.  6> _PID_GUID'AN{978AE400-61E6-11D2-8F75-C17FF64FD95A}000-C000-000000000046}Ve Oh+'0  $0 L X dpx'1Metabolism of Pesticides in Plants and LivestockPleta Eric Bechtel PericNormalc Eric Bechtel Pe8icMicrosoft Word 8.0c@<@ZE@F64FD95A}000-C000-000000000046}Ve Oh+'0  $0 L X dpx'1Metabolism of Pesticides in Plants and LivestockPleta Eric Bechtel PericNormalcanalytical methods, residue levels, and toxicity data can be generated. An adequate metabolism study fulfills at least three main purposes: (i) to identify the composition of the terminal residue in all plant commodities and livestock tissues, milk, and eggs. (ii) to indicate the distribution of the residues, i.e., (a) in plants, whether the residues are absorbed through roots and foliage or are entirely surface residues, and whether the residues are translocated, (b) in livestock, to indicate the distribution of residues in tissues, eggs, and milk, and to provide evidence of storage or accumulation in tissues. (iii) to provide a basis for determining the efficiency of extraction and clean-up procedures used in the development of analytical methodologies. c jbjbSS T11]T N  ,  / =!"#$%jbjbSS 811]~~~~  j  ,i]  c tjbjbSS T11]Dpppp |>  ,  d0dddF "" d~d  H>2pR \0\\\. "" \~\  =HN2 R Metabolism of Pesticides in Plants and Livestock The use of pesticides to control pests and disease is important for the production of sufficient quantities of safe and affordable food. However, the use of these agents sometimes leaves residues (the pesticide or its degradates) in/on plant parts used as human food or animal feed commodities. These residues may enter the human food chain either directlythrough the consumption of treated foods, e.g. grain or fruit, or indirectlythrough the transfer of residues to milk, eggs and meat products. To answer the question: What is the nature of the chemical residue in/on food or feed items resulting from the use of the pesticide?, plant and animal metabolism studies are carried out. This paper describes the aims and conduct of these studies. Use of radiolabeled pesticides The term metabolism generally refers to the chemical transformation of the pesticide which results from natural (metabolic) processes in the biological system under investigation. To measure the total residue, and to provide a means of selectively tracing products derived from the pesticide in the presence of biological material, the studies are carried out using radiolabeled pesticides. The radiolabel, usually carbon R$/07"8FR6 he total residue, and to provide a means of selectively tracing products derived from the pesticide in the presence of biological material, the studies are carried out using radiolabeled pesticides. The radiolabel, usually carbon n soil where a previous crop was treated with the pesticide, crop rotation studies are carried out. In these studies, the soil is treated with the radiolabeled pesticide and crops sown 30, 120 and 365 days after treatment. The crops are harvested at maturity and other intervals appropriate to normal agricultural practices, e.g. immature cereals which are fed to livestock as forage or silage. Livestock metabolism Studies are carried out in agricultural livestock whenever a pesticide is applied directly to animals or when treated plant commodities / =!"#$%ducts. To answer the question:  from the use of the pesticide? ll fate of pesticides under large In plant studies, the term   ll are used for animal feed. Typically, the most important species in agriculture are ruminants and poultry, howeR$/07"8F6Metabolism of Pesticides in Plants and Livestock The use of pesticides to control pests and disease is important for the production of sufficient quantities of safe and affordable food. However, the use of these agents sometimes leaves residues (the pesticide or its degradates) in/on plant parts used as human food or animal feed commodities. These residues may enter the human food chain either directlythrough the consumption of treated foods, e.g. grain or fruit, or indirectlythrough the transfer of residues to milk, eggs and meat products. To answer the question: What is the nature of the chemical residue in/on food or feed items resulting from the use of the pesticide?, plant and animal metabolism studies are carried out. This paper describes the aims and conduct of these studies. Use of radiolabeled pesticides The term metabolism generally refers to the chemical transformation of the pesticide which results from natural (metabolic) processes in the biological system under investigation. To measure the total residue, and to provide a means of selectively tracing products derived from the pesticide in the presence of biological material, the studies are carried out using radiolabeled pesticides. The radiolabel, usually carbon R$/07"8FR6 ively similar to those formed in mammals, the plant metabolites may be considered to have been tested in animals in the same studies as those performed on the parent compound. If significant qualitative or quantitative differences are found between plant and animal metabolites, additional toxicological data concerning the plant metabolites in animals may be required. The nature and extent of the additional toxicity studies will depend on the nature of the metabolite involved. Using the information from the radiolabeled studies, analytical methods are developed to determine as much of the terminal residue as possible, particularly for those components that are considered of toxicological interest. The development of analytical methods is facilitated using samples from the metabolism studies to optimize the efficiency of the extraction and clean-up procedures. "88=== J"J:JMM NNNOPP/ =!"#$% Conclusions It is essential that metabolism studies provide an accurate description of the composition of the terminal residues in food and feed items. The nature of the individual components of the terminal residue must be defined before wider range of crops will be initiated. The radiolabeled chemical is formulated and applied to the crop in a similar manner to that used in actual agricultural practice. To define the amount and nature of residues that may be found in rotated crops grown i/ =!"#$%pesticides in plants and lated foods, e.g. grain or fruit ,/ =!"#$% (ated foods, e.g., grain or fruit) (). To answer the question  transformation of the pesticide that radiolabe-  ,from ,om three different crop groups , root, cereal, top fruit ,,,cereals, whichther species theingested residues, ,radiolabe12 ?@>@b##B#R$**..////B4D4$7&7 8"812 ?@/ =!"#$%-14 or hydrogen-3, is incorporated into a metabolically stable portion of the compound. The use of the radiolabelrequires that studies are carried out in controlled areas; for plants this can be either in small field plots or pots housed in suitable growing environments. This restriction in scale implies that these studies are qualitative and, at best, a semi-quantitative estimate of the fate of pesticides under large scale field conditions.Use of radiolabeled pesticides Plant metabolism In plant studies, the term  metabolism is used in a wider context, to include the formation of all products (degradates) of the pesticide in or on the plant, regardless of weather they result from internal plant metabolic processes, from chemical reactions (hydrolysis and photolysis) or biological processes which occur outside the plant (e.g. microbiological degradation in soil). A plant metabolism study is usually carried out on crops typical of those to which the pesticide will be applied. If the metabolism of the pesticide is the same in plants from three different crop groups, e.g. root, cereal, top fruit, then no further studies are conducted. If different metabolic routes are revealed then studies in a wider range of crops will be initiated. The radiolabeled chemical is formulated and applied to the crop in a similar manner to that used in actual agricultural practice. To define the amount and nature of residues that may be found in rotated crops grown i/ =!"#$%pesticides in plants and lated foods, e.g. grain or fruit ,/ =!"#$% (ated foods, e.g., grain or fruit) (). To answer the question  transformation of the pesticide that radiolabe-  ,from ,om three different crop groups , root, cereal, top fruit ,,,cereals, whichther species theingested residues, ,radiolabeflects the proposed use pattern. The size of the dose given to the animals is often more than that expected from normal agricultural practice to facilitate the detection, isolation, and characterization of metabolites. Samples of milk, eggs, and excreta are taken throughout the dosing period. The animals are usually sacrificed within 24 hours after the final dose and tissues are taken post mortem. Animal studies must be carried out according to Good Laboratory Practice (GLP) principles./ =!"#$% Measurement and characterization of the residue In the case of compounds with a complex structure, it may be necessary to conduct two are more metabolism studies with the radiolabel located in different parts of the compound. The use of ra