PYMETROZINE (279) The first draft was prepared by Mr Christian Sieke, Federal Institute for Risk Assessment, Berlin, Germany

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1 1589 PYMETRZIE (29) The first draft was prepared by Mr Christian Sieke, Federal Institute for Risk Assessment, Berlin, Germany EXPLAATI is a pyridine azomethine insecticide used to control homopteran insects (aphids and whiteflies) as well as pollen beetles selectively. Although it has no knockdown effect, pymetrozine rapidly affects the feeding behaviour of the insect pests. It was considered for the first time by the 2 JMPR for toxicology and residues. IDETITY IS common name Chemical name IUPAC CA CAS o CIPAC o. 59 Structural formula (E)-4,5-dihydro-6-methyl-4-(-pyridylmethyleneamino)-1,2,4-triazin- (2H)-one 4,5-dihydro-6-methyl-4-[(E)-(-pyridinyl-methylene)amino]-1,2,4- triazin-(2h)-one H CH Molecular formula Molecular mass C 1 H g/mol The pymetrozine molecule contains a double bond about which E/Z isomerism is possible. However, pymetrozine technical material is manufactured by a process that yields almost exclusively the E isomer. Specifications Specifications for pymetrozine were not yet developed by FA. Physical and chemical properties Physical and chemical properties Property Results Method Reference (test material) Melting point C with thermal decomposition ECD Guideline for Rodler, 199, Boiling point & temperature of decomposition ot measurable (decomposes) Decomposition starts to occur at about 19 C Testing of Chemicals 12 (99.4% AI) PYMET_1 Relative density 1. g cm at 2 C ECD Guideline for Testing of Chemicals 19 (99.% pure AI) Fueldner, 1995, PYMET_2

2 159 Property Results Method Reference (test material) Vapour pressure < Pa at 25 C ECD Guideline for Testing of Chemicals Geoffroy, 199, PYMET_ 14A (99.4% pure AI) Henry s Law Coefficient <. 1 6 Pa m mol 1 (calculated) Calculation Burkhard, 1995, PYMET_4 Physical state, colour White fine powder Visual (99.% pure AI) Das, 1995, PYMET_5 dour dourless Spectra active substance Muller, 1995, PYMET_6 UV/vis ɛv/visa L mol 1 cm 1 (245.6 nm) ɛm)45.6 a L mol 1 cm 1 (299.2 nm) o absorption max between 4 nm and 5 nm observed UV Spectrometry IR Spectrometry (purified AI) Solubility in water including effect of ph Solubility in organic solvents Partition coefficient n-octanol / water IR 5 cm 1 -H stretch Approx. 8 cm 1 aromatic C-H stretch 1661 cm 1 aromatic C-C, C=, C= stretch 61 cm 1 aromatic C-C 18 cm 1 C- stretch 29 mg L 1 ph 6.5, 25 C, pure water 2 mg L 1 ph 5., 25 C, buffer 2 mg L 1 ph., 25 C, buffer n-hexane < 1 mg L 1 toluene 4 mg L 1 dichloromethane 1 2 mg L 1 ethanol 24 mg L 1 n-octanol 45 mg L 1 acetone 94 mg L 1 ethyl acetate 12 mg L 1 log P ow.18, 25 C, pure water log P ow 4, 25 C, buffer ph 5. log P ow.19, 25 C, buffer, ph. log P ow, 25 C, buffer ph 9. Hydrolysis rate ph 9, 25 C stable ph, 25 C stable ph 5, 25 C t1/2 51 days ph 1, 25 C t1/2 2.8 hours Photochemical degradation in water Quantum yield of direct phototransformation ph, 25 C (buffer) t 1/ days (natural sunlight at 4, 12:12 photocycle) quantum yield of direct photok = min 1 for E Z isomerisation and.26 min 1 for irreversible thermal decay of Z isomer ECD Guideline for Testing of Chemicals 15 (99.4% AI) SP (99.4% AI) ECD Guideline for Testing of Chemicals 1 (99.4% AI) ECD Guideline for Testing Chemicals 111 ([Pyridine-5- C]- pymetrozine, radiochemical purity 9.9%) UBA Draft Test Guideline Phototransformation of Chemicals in Water, Berlin, FRG 199. [Pyridine-5- C]- pymetrozine, RP 9.2% [Triazine-6- C]- pymetrozine, RP > 9% UBA Draft Test Guideline Phototransformation of Chemicals in Water, Part A, Direct Phototransformation, Berlin, FRG 199 (Pure AI 99.4%) Stulz, 1995, PYMET_ Stulz, 199, PYMET_8 Rodler, 199, PYMET_9 & Stulz, 1995, PYMET_1 Kirkpatrick, 1995, PYMET_11 Kirkpatrick, 1995, PYMET_12 & Kirkpatrick, 1995, PYMET_1 Abildt, 1994, PYMET_

3 1591 Property Results Method (test material) Dissociation pk a,1 = 4.6 (basic) ECD Guideline for constant pk a,2 = < 1 (basic) Testing Chemicals 112 (purified AI) Stability in air, photochemical oxidative. degradation Estimated half-life by hydroxyl radical oxidation is between 4 and 28 hours Calculated (Atkins method) with H radicals cm and 12:12 photocycle Reference Jakel, 199, PYMET_15 & Stulz, 1995, PYMET_16 Stamm, 1995, PYMET_1 Formulations is primarily available as a 5 g/ WG formulation. METABLISM AD EVIRMETAL FATE Metabolism studies were conducted using [Pyridine-5- C]-pymetrozine (pyridine-label) and [Triazine-6- C]-pymetrozine (triazine-label). The position of the label for both substances is presented in the following figures: H * Figure 1 [Pyridine-5- C]-pymetrozine * = C H * * = C Figure 2 [Triazine-6- C]-pymetrozine Chemical names, structures and code names of metabolites and degradation products of pymetrozine are shown below.

4 1592 Known metabolites of pymetrozine Code ames Chemical Abstracts ame (IUPAC ame), molecular formula, molar mass Structure Where found Parent pymetrozine, CGA ,5-dihydro-6-methyl-4-[(- pyridinylmethylene)-amino]- 1,2,4-triazin-[2H]-one H Rat, goat, hen Rice, cotton, potato, tomato, rotational crops CH CGA 599, 2U/IA12 4,5-dihydro-5-hydroxy-6- methyl-4-[(- pyridinylmethylene)-amino]- 1,2,4-triazin-(2H)-one H H Rat, goat, hen Rice, potato, tomato CH CGA ,5-dihydro-5-oxy-6-methyl-4- [(-pyridinylmethylene)- amino]-1,2,4-triazin-(2h)-one H Rice, tomato CH CGA 4 -pyridinecarboxaldehyde (nicotinealdehyde) Rat, goat, hen Rice, potato, tomato CGA incl. conjugates -pyridinemethanol H 2 C H Hen Rice, cotton, potato, tomato, rotational crops CGA 18 -pyridinecarboxylic acid (nicotinic acid) HC Rat, goat, hen Rice, cotton, potato, tomato, rotational crops CGA 188 -pyridinecarboxamide (nicotinamide) H 2 Rat, goat, hen Rice, potato, tomato, rotational crops CGA methyl--pyridinecarboxylic acid (trigonelline) + CH Rice, cotton, potato, tomato, rotational crops - CGA hydroxynicotinic acid Tomato H HC

5 159 Code ames Chemical Abstracts ame (IUPAC ame), molecular formula, molar mass Structure Where found CGA amino-6-methyl-1,2,4- triazine-,5(2h,4h)-dione H H 2 Rat, goat, hen Rice, cotton, potato, tomato, rotational crops CH GS 2199 incl. conjugates 6-methyl-1,2,4-triazine-,5(2H,4H)-dione H H Rat, goat, hen Rice, cotton, potato, tomato, rotational crops CH CGA ,,4,5-tetrahydro-,5-dioxo- 1,2,4-triazine-6-carboxylic acid H H Rotational crops CH CGA amino-6-methyl-1,2,4-triazin- (2H)-one H H 2 Rat Potato, tomato CH CGA ,5-dihydro-6-methyl-1,2,4- triazin-(2h)-one H H Rat, goat, hen Rice, potato, tomato CH I A 4,5-dihydro-6-methyl-4-[(-(1- methyl-6-oxo-1,6- dihydropyridinylmethylene)- amino]-1,2,4-triazin-(2h)-one H Hen CH CGA ,5-dihydro-6-methyl-4-[(-(1- oxy)-pyridinyl-methylene)- amino]-1,2,4-triazin-(2h)-one H + - Goat CH CGA ,5-dihydro-6-hydroxymethyl- 4-[(-pyridinyl- methylene)amino]-1,2,4- triazin-(2h)-one H Rat, goat CH 2 H

6 1594 Code ames Chemical Abstracts ame (IUPAC ame), molecular formula, molar mass Structure Where found 5U/I A2 4,5-dihydro-6-carboxy-4-[(- pyridinyl methylene)-amino]- 1,2,4-triazin-(2H)-one H Rat, goat CH II A2 phosphate conjugate of CGA 1124 Goat I A1 hydroxylated - pyridinecarboxaldehyde Goat CGA (4,5-dihydro-6-methyl-,5- dioxo-1,2,4-triazin-4(2h)-yl)- acetamide Rat, hen Animal metabolism The Meeting received metabolism studies on laboratory animals, poultry and lactating goats using the pyridine- and the triazine-label of pymetrozine. The metabolism of pymetrozine in livestock animals was intensive, showing only minor amounts of unchanged parent substance in all matrices. The major degradation steps are: oxidation at the triazine-methyl group leading to alcohol CGA1124, and subsequently to the corresponding carboxylic acids (A2 and 5U) oxidation at the triazine methylene group leading to metabolite CGA599, and subsequently after cleavage between the triazine and pyridine ring to triazine-specific CGA and GS2199 cleavage reaction between the triazine and pyridine ring systems leading by various reaction mechanisms to triazine-specific compounds CGA5525, CGA24925, CGA259168, and pyridine-specific metabolites CGA18, CGA 188 and CGA4. Laboratory animals In the rat the extent of oral absorption is high (> 8%), based on urinary and biliary data. is widely distributed in the body. High concentrations of both triazine- and pyridine-labelled material were found in the liver and kidney. The labelled material was rapidly excreted via urine (55% in 24 hours). Absorbed pymetrozine was extensively metabolized, with unmetabolized parent compound representing approximately 1% of the excreted radiolabel. Compounds containing both ring structures represented over 5% of the identified metabolites. The kinetics, excretion pattern, tissue distribution of radioactivity and metabolite profile were similar for both radiolabelled sites and administered dose levels as well as when the administration of radiolabelled pymetrozine was preceded by days of administration of the unlabelled material (see WH Monograph).

7 1595 Lactating goats The metabolic fate of [pyridine-5- C]-pymetrozine in lactating goats was investigated by Rümbeli (1994, PYMET_18). The compound was administered to two lactating goats (5 bw and 49 bw) in gelatine capsules at.9 mg/ body weight, corresponding to a level of.5 ppm in the feed, for four consecutive days. Excreta and milk were collected daily. The animals were slaughtered approximately 6 hours after the last dose. Muscle, omental fat, peritoneal fat, liver, kidney, blood, bile and content of gastrointestinal tract/rumen were collected. Radioactivity was measured using liquid scintillation counting. Thin-layer chromatography, high performance liquid chromatography and high voltage electrophoresis were used to identify and characterise radioactive components in sample extracts. The total recovery of the administered radioactivity was 86.5 %. The majority of the recovered radioactivity was found in the urine (52.4%) and faeces (.%). f the administered radioactivity.1% were excreted via milk. Radioactive residues in the edible tissues, muscle, omental fat, peritoneal fat, liver and kidney were between 1.95% of the administered dose. There was.58% of the dose remaining in leg muscle, % in tenderloin, 1.95% in liver and.15% in kidney. A summary of the recovered radioactivity is presented in Table 1. Table 1 Recovered radioactivity from goat tissues and excreta after administration of [pyridine-5- C]- pymetrozine Tissue Mean radioactivity (mg/ or mg/l pymetrozine eq.) Mean radioactivity (% of total dose) Milk (8 h) 6. Leg muscle Tenderloin.69 mental fat 6 Perirenal fat 2 Kidney Liver Faeces (8 h) Urine (8 h) Cage debris.65 Cage wash 2.4 Blood.69 5 Bile 1. GIT/rumen Total excreted. Total recovery Unchanged pymetrozine was present in small amounts ranging between 1.6% in liver tissue and 1.8% in muscle and were equivalent to.1 mg eq/ or less in all samples except liver and kidney where the equivalent residues was mg eq/ and. mg eq/, respectively. In tissue nicotinamide (CGA188) was a major metabolite found in muscle (44.2%), fat (2.%), liver (6.5%) and kidney (2.4%). The hydroxylated pymetrozine derivative CGA1124 was found as a residue in muscle (1%), fat (6.8%), liver (.%) and kidney (11.%) with residues greater than.1 mg eq/ in liver and kidney. CGA1124 was also the major metabolite in milk at 6.% of the radioactive residue. The phosphate conjugate of CGA1124 was also found in milk, accounting for an additional 8.9% of the radioactive residue. For the composition of radioactive residues in milk and tissues please see Table 2.

8 1596 Table 2 Composition of radioactive residues in goats tissues and milk after administration of [pyridine-5- C]-pymetrozine Metabolite Fractions in mg eq/ (% TRR) a Muscle Fat Milk (8 h) Liver b Kidney TRR Identified. (1.8).1 (4.9).11 (.4) 4 (1.6). (9.8) 5U/I A2.8 (1.2).6 (2.2).64 (4.) 8 (5.) CGA18.51 (.1) CGA (1).18 (6.8).118 (6.) 4 (.).81 (11.) CGA (8.9) phosphate conjugate CGA188 (44.2).64 (2.).2 (.).54 (6.5).19 (2.4) CGA599.6 (1.1) CGA4.6 (.9).82 (2.5) IA1.9 (1.2).8 (1.) Characterised IA1 (start).128 (18.8).15 (5.5) 2 (15.) 6 (6.4) IIA1.1 (.2) thers Unresolved.82 (12.).2 (8.6) 5 (.). (25.2).15 (.6) Hexane phase. (1.1).16 (9.2). (.1). () Sub-total.65 (99.2) 45 (9.9).1 (95.1) 1.4 (96.5).588 (81.9) Unextracted.24 (.5). (5.1).95 (2.9). (1.4).89 (12.4) Total.698 (12.) 59 (96.).19 (98.) 1.45 (9.9).6 (94.) a Means of both animals b After microwave extraction For the investigation of the stability of residues during freezer storage, samples of liver, milk and milk extract were re-analysed after 12 months by TLC and the pattern was compared to the first analysis: Table Storage stability of liver, milk and milk extract samples from lactating goats dosed with [pyridine- C]-pymetrozine Fraction % TRR Liver 9 months storage Liver 2 months storage Milk 1 month storage Milk extract 1 additional month storage I A CGA phosphate conjugate CGA pymetrozine CGA CGA unresolved Milk 2 month storage The metabolism of lactating goats using [triazine C]-pymetrozine was investigated by Rümbeli (1994, PYMET_19). Two animals ( & 41 bw) were administered doses equivalent to.54 mg/ bw or 1 ppm in the diet for a period of four consecutive days. Excreta and milk were collected daily. The animals were slaughtered approximately 6 hours after the last dose. Muscle, omental fat, peritoneal fat, liver, kidney, blood, bile and content of gastrointestinal tract/rumen were collected. Radioactivity was measured using liquid scintillation counting. Thin-layer chromatography, high performance liquid chromatography and high voltage electrophoresis were used to identify and characterise radioactive components in sample extracts.

9 159 The total recovery of the administered radioactivity was 8.4 %. The majority of the recovered radioactivity was found in the urine (4.1%) and faeces (16.6%). f the administered radioactivity.% were excreted via milk. Radioactive residues in the edible tissues, muscle, omental fat, peritoneal fat, liver and kidney were between 1.9% of the administered dose. There was.8% of the dose remaining in leg muscle, % in tenderloin, 1.9% in liver and.9% in kidney. A summary of the recovered radioactivity is presented in Table 4. Table 4 Recovered radioactivity from goat tissues and excreta after administration of [triazine-6- C]- pymetrozine at 1 ppm Tissue Mean radioactivity (mg/ or mg/l pymetrozine eq.) Mean radioactivity (% of total dose) Milk (8 h).44.1 Leg muscle.8 Tenderloin mental fat.19.6 Perirenal fat.69.1 Kidney.5.9 Liver Faeces (8 h) Urine (8 h) Cage debris Cage wash 2.46 Blood Bile GIT/rumen Total excreted.11 Total recovery 8.5 Unchanged pymetrozine was present in small amounts ranging between 2.% TRR in liver tissue and 1% TRR in muscle. In tissue the hydroxylated pymetrozine derivative CGA1124 was found as a major residue in fat (24.% TRR) and kidney (15.1% TRR) and in concentrations of.51 mg eq/ in liver. CGA1124 was also the major metabolite in milk with 4% of the TRR. The phosphate conjugate of CGA1124 was also found in milk, accounting for an additional 4.% TRR. In kidney, 5U/I A2, which represents the carboxylic acid of pymetrozine, was also identified as a major metabolite (11.% TRR,.6 mg eq/). For the composition of radioactive residues in milk and tissues please refer to Table 5. Table 5 Composition of radioactive residues in goats tissues and milk after administration of [triazine- 6- C]-pymetrozine at 1 ppm Metabolite Fractions in mg eq/ (% TRR) a Muscle Fat Milk (8 h) Liver b Kidney TRR Identified.4 (1).1 (.2).15 (.) 4 (2.).52 (9.) 5U/I A2.6 (6.8).8 (.5).6 (11.) CGA (2.6).98 (9.2) CGA (1.2) CGA (9.5).24 (24.).19 (4).51 (4.8).8 (15.1) CGA (4.) phosphate conjugate CGA (.).24 (2.4) 2 (.) (.5) CGA599. (.) GS (.).24 (2.4) (2.2).18 (.2) Characterised IA1 (start).1 (2.6).26 (2.) 6 (24.).64 (11.2)

10 1598 Metabolite Fractions in mg eq/ (% TRR) a Muscle Fat Milk (8 h) Liver b Kidney IIA1.11 (2.5) thers Unresolved.86 (18.2) 4 (4.8) 8 (8.4).45 (42.2).155 (2) Hexane phase.2 (4.9).5 (.6). (.) Sub-total (9.1).9 (92.1).429 (96) 1.5 (98.8).46 (8.) Unextracted.1 (22.).46 (4.) (6.6).1 (.9) (12.9) Total (11.4).949 (96.8).459 (12.6) 1.6 (99.).56 (9.6) a :Means of both animals b After microwave extraction For the investigation of the stability of residues during freezer storage, samples of liver, milk and milk extract were re-analysed after 92 months by TLC and the pattern was compared to the first analysis: Table 6 Storage stability of liver, milk and milk extract samples from lactating goats dosed with [triazine- C]-pymetrozine Fraction % TRR Liver 1 months storage Liver 2 months storage Milk 11 month storage Milk extract 9 additional month storage I A U/I A CGA CGA phosphate conjugate pymetrozine CGA CGA GS unresolved Milk 2 month storage Laying hens The metabolic fate of [pyridine-5- C]-pymetrozine was studied in five laying leghorn hens by Rümbeli (1994, PYMET_2). The compound was administered in gelatine capsules at.82 mg/ body weight, corresponding to a level of 1.8 ppm in the diet, for four consecutive days. Excreta and eggs were collected daily. The animals were slaughtered approximately 6 hours after the last dose. Muscle, skin with attached fat, peritoneal fat, liver, kidney and content of gastrointestinal tract were collected. Radioactivity was measured using liquid scintillation counting. Thin-layer chromatography, high performance liquid chromatography and high voltage electrophoresis were used to identify and characterise radioactive components in sample extracts. The total recovery of the administered radioactivity was 9.%. The gastrointestinal tract was not analysed, which may account for most of the remaining administered radioactivity. The majority of the radioactivity (.%) was found in the excreta. Radioactive residues in the edible tissues were % TRR in lean meat,.5% TRR in skin and fat,.% TRR in liver,.11% TRR in kidney and % TRR in eggs. A summary of the recovered radioactivity is presented in Table. Table Radioactive residues in eggs and tissues after oral administration of [pyridine-5- C]- pymetrozine for 4 consecutive days at a dose of.82 mg/ body weight day (1.8 ppm) Tissue Mean radioactivity (mg/ or mg/l pymetrozine Mean radioactivity (% of total dose) eq.) Egg white (8 h)..16 Egg yolk (8 h).4.5

11 1599 Tissue Mean radioactivity (mg/ or mg/l pymetrozine Mean radioactivity (% of total dose) eq.) Total egg (8 h).6. Lean meat 69 Skin + fat 4.52 Peritoneal fat.11.9 Liver Kidney Blood 9 Gizzard 1.64 Excreta Cage wash.58 Total excreted.4 Total recovery 9.48 Unchanged pymetrozine was present in very small amounts only detectable in egg white (4.9% TRR) and kidney (% TRR). In all tissues and eggs CGA18 (nicotinic acid) & CGA188 (nicotinamide) were the major residue present at 8.6 % TRR to 6.5% TRR. The only other major metabolites identified were IA (skin + fat: 16.6% TRR, egg white: 15.4% TRR and kidney: 12.5% TRR) and CGA4 (egg white: 11.1% TRR). For the composition of radioactive residues in milk and tissues please refer to Table 8. Table 8 Identification of radioactivity in hens after oral administration of [pyridine-5- C]- pymetrozine for 4 consecutive days at a dose of.82 mg/ body weight day (1.8 ppm) Metabolite Fractions in mg eq/ (% TRR) a Lean meat Skin + fat Egg white b Egg yolk b Liver Kidney TRR Identified pymetrozine.1 (4.9).1 () CGA18.15 (1.6).6 (64.) I A.2 (5.).8 (16.6).2 (15.4) 2 (2.4).65 (12.5) CGA188 (6.5).12 (62.6).8 (28.2).1 (8.6).652 (.). (1.) CGA599 <.1 (1.) CGA12862 <.1 (2.2) CGA4 <.1 (1.8).1 (11.1) Characterised I A1 (start) <.1 (1.).11 (5.9) <.1 (8.1).26 (26.1) 4 (4.8).88 (1.) I A5.64 (6.9) 6 (.) thers Unresolved.4 (.8).8 (4.2).12 (1.).28 (2.8).56 (6.).46 (8.9) Hexane phase <.1 (1.1) <.1 (1.9) <.1 (.8).16 (.) Soxhlet 4 (4.8) Sub-total (92.1).18 (9.).89 (8.6).2 (1.6).89 (96.8).51 (96.6) Unextracted.29 (6.).2 (1.8).1 (9.6).19 (19.1) 6 (.9).8 (1.5) Total 2 (98.8).19.9 (9).91 (9.).9 (1.).59 (98.1) (1.8) a Mean of animals 28 h For the investigation of the stability of residues during freezer storage, samples of lean meat and liver were re-analysed after 2 months by TLC and the pattern was compared to the first analysis:

12 16 Table 9 Storage stability of lean meat and liver samples from laying hens dosed with [pyridine- C]- pymetrozine Fraction % TRR Lean meat 1 month storage Lean meat 2 month storage Liver month storage I A CGA I A I A CGA unresolved Liver 2 month storage The metabolic fate of [triazine-6- C]-pymetrozine was studied in five laying leghorn hens by Rümbeli (1994, PYMET_). The compound was administered in gelatine capsules at.9 mg/ body weight, corresponding to a level of 1.4 ppm in the diet, for four consecutive days. Excreta and eggs were collected daily. The animals were slaughtered approximately 6 hours after the last dose. Muscle, skin with attached fat, peritoneal fat, liver, kidney and content of gastrointestinal tract were collected. Radioactivity was measured using liquid scintillation counting. Thin-layer chromatography, high performance liquid chromatography and high voltage electrophoresis were used to identify and characterise radioactive components in sample extracts. The total recovery of the administered radioactivity was 8.8%. The gastrointestinal tract was not analysed, which may account for most of the remaining administered radioactivity. The majority of the radioactivity (82%) was found in the excreta. Radioactive residues in the edible tissues were.% TRR in lean meat, 4% TRR in skin and fat,.86% TRR in liver, 2% TRR in kidney and.55% TRR in eggs. A summary of the recovered radioactivity is presented in Table 1. Table 1 Recovery of applied radioactivity in hens after oral administration of [triazine-6- C]- pymetrozine for 4 consecutive days at a dose of.9 mg/ body weight day (1.4 ppm) Tissue Mean radioactivity (mg/ or mg/l pymetrozine Mean radioactivity (% of total dose) eq.) Egg white (8 h) 9 Egg yolk (8 h).6.6 Total egg (8 h) Lean meat..4 Skin + fat.19 4 Peritoneal fat..4 Liver.1.86 Kidney Blood 2 4 Gizzard Excreta 81.1 Cage wash 8 Total excreted 82.6 Total recovery 8.81 Unchanged pymetrozine was present in small amounts representing 1% to 4.8% of the TRR. In all tissues and eggs CGA was the major residue present at 6.6 % TRR to 44.8% TRR. In addition I A was also a major metabolite in all matrices (5.1% to 48.5% of the TRR). In meat and egg white CGA represented 11.1% TRR and 1.4% TRR, respectively, while GS2199 was a major metabolite in egg white only (1.4% TRR). For the composition of radioactive residues in milk and tissues please refer to Table 11.

13 161 Table 11 Identification of radioactivity in hens after oral administration of [triazine-6- C]- pymetrozine for 4 consecutive days at a dose of.9 mg/ body weight day (1.4 ppm) Metabolite Fractions in mg eq/ (% TRR) a Lean meat Skin + fat Egg white b Egg yolk b Liver Kidney TRR Identified pymetrozine <.1 (1.) <.1 (1.).1 (2.9).2 (1.9).8 (4.8) CGA (8.9).4 (24.4).11 (44.8).2 (1.). (6.6).18 (11.) I A.1 (5.1).8 (22.). (11.1) 8 (26.6).9 (48.5) CGA (11.1).1 (6.2). (1.4) <.1 (.5).2 (2.).6 (.9) GS2199 <.1 (2.2) <.1 (2.6) <.1 <.1 (.5).2 (2.).6 (.9) (1.4) Characterised I A1 (start).1 (5.).19 (12.5).26 (1.4) <.1 (6.1) 4 (22.5).28 (1.) thers Unresolved.52 (24.8). (9.5).25 (1).56 (44.) 9 (2.1) 4 (2.) Hexane phase <.1 (2.) <.1 (.) <.1 (.1) <.1 (4.5).28 (2.6).15 (.9) Soxhlet.51 (4.8) Sub-total.19 (9.).12 (82.2) (91.1).95 (.).99 (9.6).152 (9.8) Unextracted.19 (9.2).25 (16.5).1 (.9). (11.1).65 (6.1). (4.4) Total. (99.9).8 (98.) 4 (95).9 (4.4).16 (99.).159 (98.2) a Mean of animals 28 h For the investigation of the stability of residues during freezer storage, samples of lean meat and liver were re-analysed after 2 months by TLC and the pattern was compared to the first analysis: Table 12 Storage stability of lean meat and liver samples from laying hens dosed with [triazine- C]- pymetrozine Fraction % TRR Lean meat 11 month storage Lean meat 2 month storage Liver 8 month storage I A CGA I A pymetrozine CGA GS2199 unresolved Liver 2 month storage

14 162 H CGA5944 G, H, Rt CH H CH + CGA24542 G CGA599 H CH H G, H, Rt H CH I A H CH H CH 2 H CGA1124* G, Rt H Met 5U G, Rt CH H H 2 H 2 H CGA4 G, H, Rt CH CH CGA5525 Rt CGA G, H, Rt H H H H H H H CGA12862 (P) H H CGA18 (P)* G, H, Rt I A1 * G CH CGA24925* G, H, Rt CH CGA (I A6 ) H, Rt CH GS2199 G, H, Rt H 2 CGA188 (P) G, H, Rt CH H 2 4bU (P) Rt P = atural product G = Goat H = Hen Rt = Rat * = also present in conjugate form. Figure Metabolic pathway of pymetrozine in animals Plant metabolism The fate of pymetrozine in plants was investigated following foliar and granular application of [pyridine-5- C]- and/or [triazine-6- C]-radiolabelled active substance to tomato, potato, cotton and rice. In the first weeks after treatment most of the residue was found on the leaf surface, consisting of unchanged parent substance. Within 4 weeks most of the residue is taken up by the plant and metabolised. Main metabolic steps are oxidation to CGA599 and CGA2584, cleavage of the parent showing both pyridine and triazine metabolites and finally incorporation into glucose, lignin and protein. A proposed metabolic pathway scheme is presented in Figure 4. Tomato The metabolism of pymetrozine was investigated in tomatoes after three spray applications with [triazine-6- C]-pymetrozine by Sandmeier (1999, PYMET_22). Fruit bearing plants were treated with rates equivalent to.4 ai/ha per application with one week s. The plants were protected by a plastic housing and watered by irrigation to avoid run-off of the residues. Samples (mature fruit and leaves) were harvested, and days after the last treatment. All samples were stored for a period of 6 months or less. Tomatoes were dipped and rinsed in methanol. The washings were combined prior to analysis by radio-assay and TLC. Washed tomatoes homogenised in the presence of liquid nitrogen. The total

15 16 radioactive residues in tomatoes and leaves were determined by liquid scintillation counting after combustion of the homogenised samples. The homogenised plant material was extracted with methanol:water (8:2). This procedure was repeated twice with tomato samples and three times with leaf samples until the last extract contained less than 5% of the radioactivity of the first extract. A Soxhlet extraction with methanol was carried out and the unextracted radioactivity was determined by combustion analysis. Characterisation and identification of radioactive components was performed with HPLC-MS using electro spray ionisation (ESI) and atmospheric pressure ionisation (APCI) techniques. The TRR in fruit was similar at the three sampling s:.58 mg/ pymetrozine equivalents after days,.5 mg/ pymetrozine equivalents after days and.51 mg/ pymetrozine equivalents after days. The TRR in leaves decreased from 2.9 mg/ pymetrozine equivalents, days after the final treatment to.6 and 1 mg/ pymetrozine equivalents after and, respectively. Surface washings of the fruit contained 68, 59 and 48.6% of the TRR at s of, and days, respectively, after the final application (see Table 1). Table 1 Summary of the distribution of radioactivity and residual [triazine-6- C]-pymetrozine in tomato plants Days after final application Crop part Total Surface Extractable radioactivity Unextracted Total residues radioactivity (% TRR) (% TRR) (mg eq/) (% TRR) Cold Soxhlet (% TRR) (% TRR) Tomatoes Leaves 2.95 /A Tomatoes Leaves.585 /A Tomatoes Leaves 1.46 /A was the major residue in fruits ranging from 56.8% TRR after days to 1.9% TRR after days. o other fraction accounted for more than 1% of TRR in fruit except CGA after days (1.5% TRR,.691 mg eq/). Table Quantification of metabolite fraction in tomato plants days after the final [triazine-6- C]- pymetrozine application days after final application Fraction Fruit Leaves Washing + extract Extract % TRR mg eq/ % TRR mg eq/ TRR Identified pymetrozine CGA CGA CGA CGA GS GS 2199 n-gluc CGA Characterised I I I I I I 6a I 6b

16 164 days after final application Fraction Fruit Leaves Washing + extract Extract % TRR mg eq/ % TRR mg eq/ I 1a I I 1b.55 ther Unresolved Soxhlet Unextracted Total Table 15 Quantification of metabolite fraction in tomato plants days after the final [triazine-6- C]- pymetrozine application days after final application Fraction Fruit Leaves Washing + extract Extract % TRR mg eq/ % TRR mg eq/ TRR Identified pymetrozine CGA CGA CGA CGA GS GS 2199 n-gluc CGA Characterised I I I I I I 6a I 6b I 1a I I 1b 2 ther Unresolved Soxhlet Unextracted Total Table 16 Quantification of metabolite fraction in tomato plants days after the final [triazine-6- C]- pymetrozine application days after final application Fraction Fruit Leaves Washing + extract Extract % TRR mg eq/ % TRR mg eq/ TRR Identified pymetrozine CGA CGA CGA CGA

17 165 days after final application Fraction Fruit Leaves Washing + extract Extract % TRR mg eq/ % TRR mg eq/ GS GS 2199 n-gluc CGA Characterised I 1 (start) I I I I I 6a I 6b I 1a I I 1b.1.19 ther Unresolved Soxhlet Unextracted Total In an older set of studies also conducted by Sandmeier (1992, PYMET_2 & 199, PYMET_24) the distribution and degradation of [triazine-6- C] pymetrozine was studied in field grown tomatoes after foliar application. Three months old tomato plants (with green tomatoes, approx. 2 cm in diameter) were twice treated in an of days with a WP formulation at a rate of about 5 ai/ha each. The sampling followed two strategies. In a short-term experiment plant material (tomatoes and leaves) was sampled about 1 and 4 hours; 1, 2 and days after the last application. The long-term experiment involved sampling 26 and 49 days. All samples were analysed within 22 months. Leaves and tomatoes were shortly washed with MeH/H 2. After cold extraction a soxhlet extraction with methanol was performed. The unextracted radioactivity was determined by combustion of the dry material. The radioactivity was measured with a scintillation counter or by autoradiography. Besides the TLC Liquid Chromatography, HPLC, chemical reactions and enzyme cleavage were used to characterise fractions. Quantification of metabolites was performed by 2D TLC. In the short-term experiment about 5% of the initial radioactivity was found after seven days in the treated leaves and fruits. Most of the residue was present on the surface consisting of unchanged parent substance. However, a quick and steady absorption into the plants was observed. In the extracts, the amount of pymetrozine was lower than on the surface, indicating a quick degradation within the plants. An overview of the radioactivity found in tomato samples is presented below. All samples were analysed only for the amount of pymetrozine present. Table 1 Penetration of radioactivity and residual [triazine-6- C]-pymetrozine in tomato leaves and fruits Interval Plant part Total residue Surface wash Extracts Total mg eq/ mg/ % TRR % pymetrozine % TRR % pymetrozine % unextracted % TRR 1 hr leaves fruits hrs leaves fruits day leaves fruits

18 166 2 days leaves fruits days leaves fruits In the long-term experiment the composition of the radioactive residues in tomato leaves and fruits was investigated. After 26 and 49 days the parent substance was extensively metabolized. Although pymetrozine was still present as the only major metabolite in treated plant parts (8.61.2% TRR), most of the recovered radioactivity was distributed into minor metabolites or characterised. Table 18 Quantification of metabolite fractions in various tomato plant parts after spray application of [triazine-6- C]-pymetrozine Fraction Metabolite Fractions in mg eq/ (% TRR) 26 days 49 days upper upper upper treated treated fruit, leaves, fruit, lower lower newly newly newly fruit leaves grown grown grown treated lower fruit upper leaves, newly grown treated lower leaves TRR Identified pymetrozine CGA5525 CGA24925 CGA599 CGA GS2199 GS2199 n- Gluc Characterised I 1 (start) I 2 I I 4 I 6 I 1 Soxhlet & unresolved Unextracted Total 5 (1) (1.). (.9).5 (1.4) <.1 (1.9) (8.5).18 (5.2).5 (1.5).9 (22.2) <.1 (2.1) <.1 (2.2) <.1 (.) <.1 (1.1) <.1 (.5).62 (1.4) 5 (12.).4 (95.6) (12.2).6 (1.1).16 (1.2) 9 (1.8) 9 (2.1).49 (.).611 (4.6) 1.82 (1.) 9 (2.1).1 (.8).12 (.9).8 (1) 52 (1.9) 2.42 (18.2) 4.56 (4.) 1.1 (98.2) <.1 (.).1 (2.2).5 (8.9).1 (2.2) 5 (4.4) <.1 (2.2) <.1 (1.) <.1 (4.9).86 (16.2).8 (15.).5 (11) (9.8) <.1 (.).5 (2.1) <.1 (1.4) (8.9).16 (.1).4 (1.8).6 (2.5) <.1 (1.8) <.1 (1.5) <.1 (.4) <.1 (.) <.1 (.4) (1.) 4 (15). (.2).16 (1.2).52 (.9).116 (8.6).16 (12.1) <.1 (.) (8.6).12 ().89 (1.4).89 (1.4).1 (1.9).1 (2.1).42 (6.6).815 (12.8) 6 (4.2) (.5) (1.8).8 (1.) <.1 (.5) 4 (15.1).62 (45.8). (1.1).81 (12.) 2.8 (44.2) 2 (96) 1. (96.5) 6. (99) Distribution and degradation of [pyridine-5- C]-pymetrozine were studied by Gross (1994, PYMET_25) in field-grown tomatoes protected by a plastic housing. Three month old tomato plants (with green tomatoes approximately 2 cm diameter) were treated twice at days with approximately 5 ai/ha formulated in a WP product. Whole plants were sampled approximately hours and 15 days after the first application, and at 1 hour, days (first mature fruit) and 2 days (maturity) after the second application.

19 16 Tomatoes were rinsed in methanol:water (1:1 v/v). The total radioactive residues were determined by liquid scintillation counting after combustion of the homogenised samples. The homogenised plant material was extracted thrice with methanol:water (8:2). The combined extracts were used for determination of the parent by TLC. A Soxhlet extraction with methanol was also carried out and the unextracted radioactivity was determined by combustion analysis. Characterisation and identification of radioactive components was performed with TLC, ion exchange LC, HPLC using authentic standards of metabolites as reference compounds, and GC-MS. The first mature tomato fruits were harvested days after the second treatment. Total residues were 29 mg eq/ with a parent content of mg eq/. Total residues in leaves were.42 mg eq/ with a parent content of 2.2 mg eq/. At harvest (2 days after the second treatment), total residues reached.1 mg eq/ in tomato fruit and 2.4 mg eq/ in leaves. Parent residues were.16 mg eq/ and 86 mg eq/ in fruit and leaves respectively. The radioactivity of the surface of tomato fruit decreased from nearly 9% 1 hour after the first treatment to less than 1% 15 days later. An overview of the total radioactive residues and their extractability is presented in Table 19. Table19 Summary of the distribution of radioactivity and residual [pyridine-5- C]-pymetrozine in tomato plants Days after final application h after 1 st application 15 days after first application 15 days (1 h after 2 nd application) 2 days ( days after 2 nd application 42 days (2 days after 2 nd application) Total residues (mg eq/) (mg eq/) Surface radioactivity (% TRR) Extractable radioactivity Unextracted (% TRR) Total (% TRR) Crop part Cold Soxhlet (% TRR) (% TRR) Leaves Fruit Leaves Fruit Leaves Fruit Leaves Fruit Leaves Fruit The composition of radioactive residues showed unchanged pymetrozine as the only significant residue directly after application. Most of the parent was located on the fruit and leaf surface. Within the first days after treatment the active substance is absorbed and in plants degraded into various minor metabolites. The major metabolite identified was CGA96956, representing up to % of the TRR in fruits and leaves. The only other major metabolite found in fruits and leaves was CGA12862 present up to 19.5% of the TRR. Table 2 Quantification of metabolite fraction in tomato plants hours and 15 days after first application of [pyridine-6- C]-pymetrozine Fraction h after the first application 15 days after the first application Fruit Leaves Fruit Leaves Surface Extract Total Surface Extract Total % TRR % TRR mg eq/ (% TRR) mg eq/ (% TRR) % TRR % TRR mg eq/ (% TRR) TRR Identified mg eq/ (% TRR)

20 168 Fraction h after the first application 15 days after the first application Fruit Leaves Fruit Leaves Surface Extract Total Surface Extract Total % TRR % TRR mg eq/ (% TRR) mg eq/ (% TRR) % TRR % TRR mg eq/ (% TRR) mg eq/ (% TRR) pymetrozine (6.4) (9.).62 (16.) (84.8) CGA (1.).8 (.2) (26.4) (.1) CGA (.6).52 (4.8) (8.6) 5 (6.6) (sugar conj) CGA19251 (.4).5 (1.5) CGA18.4 <.1 (.4) CGA188.8 <.1 (.6) CGA (1.2) (2.1).8.1 (.8).92 (2.4) CGA4.5 (.).16 (1.5) <.1 (.) () Characterised IP2a. <.1 (.) IP5 IP8.8.1 (.8) 2U (2.).5 <.1 (.5) Unresolved (2.9) 8 (2.6) (2.2).15 (.9) Soxhlet.1 <.1.44 (4.1).5 <.1 2 (1.1) (.1) (.5) Unextracted.8.4 (.8) 1. (9.5)..5 (.).55 (.) Total.526 (9.8) 1 (92.6).129 (98.4).61 (94.5) Table Quantification of metabolite fraction in tomato plants 1 hour and days after second application of [pyridine-6- C]-pymetrozine Fraction 1 h after the second application days after the second application Fruit Leaves Fruit Leaves Surface Extract Total Surface Extract Total % TRR % TRR mg eq/ (% TRR) mg eq/ (% TRR) % TRR % TRR mg eq/ (% TRR) mg eq/ (% TRR) TRR Identified pymetrozine (58.5) (28.2) (8.1) (29.9) CGA (9.) (2.) (12.5) (4.5) CGA (.).8 (6.1) (19.1) (sugar conj) (11.5) CGA (.9).1 (1.8) CGA (.9) CGA (.1) 1..2 (1.) CGA (.).19 (1.4) 2..5 (2.). (1.9) CGA (1.8) 2 (1.6) (1.9).52 (.) Characterised IP5 <.1 () IP8.1.1 (.1).4 <.1 (.4) 2U 1..1 (1.) 1.. (1.) Unresolved (1.). (2.2) (.).1 (4.2) Soxhlet.1.1 (.1).59 (4.).8.2 (.8).89 (1.2) Unextracted.. (.) 1.2 (.5) (5.4) 1.2 (1.)

21 169 Fraction 1 h after the second application days after the second application Fruit Leaves Fruit Leaves Surface Extract Total Surface Extract Total % TRR % TRR mg eq/ (% TRR) mg eq/ (% TRR) % TRR % TRR mg eq/ (% TRR) mg eq/ (% TRR) Total 1.2 (99.1) (91.8) 2 (99.1).2 (94.5) Table 22 Quantification of metabolite fraction in tomato plants 2 days after second application of [pyridine-6- C]-pymetrozine Fraction 2 d after the second application Fruit Leaves Surface Extract Total % TRR % TRR mg eq/ (% TRR) mg eq/ (% TRR) TRR Identified pymetrozine (6.8) 56 (1.5) CGA (65.1).8 (2.9) CGA (.6).65 (8.6) (sugar conj) CGA (1.8) CGA18. <.1 (.) CGA (1.) CGA (1.1) 2 (1.) CGA4.1 <.1 (.1).12 (.5) Characterised IP2a <.1 () IP5.1 <.1 (.1) IP8..1 (.8) 2U <.1 () Unresolved.4.8. (4.2).68 (2.8) Soxhlet.4 <.1 (.4) (1.1) Unextracted 4.2. (4.2).418 (1.1) Total.159 (92.1) 2.1 (94.) Potato For the investigation of the plant metabolism of pymetrozine in potato a study was conducted by Fleischmann (2, PYMET_26) involving treatment either with [triazine- C]-pymetrozine or [pyridine- C]-pymetrozine formulated as a WP product. The plants were treated with three foliar sprays in one week s. The applications using [triazine- C]- and [pyridine- C]-pymetrozine were conducted with.15 ai/ha each (total rate.45 ai/ha) or at exaggerated rates of 1.5 ai/ha each (total rate.1 ai/ha). The first of the three foliar spray applications was 61 days after planting. Potato foliage and tubers were harvested, and 29 days after the third application. Samples were extracted with acetonitrile:water (8:2) or methanol:water (8:2) and purified using C 18 SPE techniques. Unextracted radioactivity in tubers were refluxed with neutral solvent acetonitrile/water or methanol/water. Additional radioactive residues were released after treatment with enzymes and then refluxing with acid or an alternative sequence refluxing with H 2 and then refluxing with base. Extracts were characterised by reverse phase HPLC and 2D-TLC. Radioactivity in liquid samples and extracts were determined by LSC. The TRR in potatoes treated at a rate of.15 ai/ha with [triazine- C]-pymetrozine were.1,.12 and.11 mg eq/ pymetrozine equivalents in tubers and 11., 8.5 and 6.4 mg eq/ pymetrozine equivalents in foliage harvested at, and 29 days after the final application, respectively. The TRR in potatoes treated with rates of 1.5 ai/ha were.4,.41 and. mg eq/ in tubers and 46.2,.2 and 4.4 mg eq/ in foliage harvested after, and 29 days, respectively.

22 161 Potatoes treated at a rate of.15 ai/ha with [pyridine- C]-pymetrozine had TRRs of 6,.1 and.6 mg eq/ in tubers and 8.2, 6.8 and.8 mg eq/ in foliage harvested at,, and 29 days, respectively. The treatments with 1.5 ai/ha using [pyridine- C]-pymetrozine resulted in tuber residues of.8,.8 and 1.1 mg eq/ and foliage residues of 29.4, 1.4 and 5.6 mg eq/ at the same respective harvest s. A summary of the total radioactive residues is presented in Table 2. Table 2 Summary of extraction of potato samples following treatment with [pyridine-5- C]- and [triazine-6- C]-pymetrozine Substrate Interval TRR Extracted residues (AC:H 2 ) mg % TRR mg eq/ eq/ Extracted residues (MeH:H 2 ) % TRR mg eq/ Unextracted % TRR mg eq/ Total % TRR Triazine- C-label Tubers,.15 DAT ai/ha DAT DAT Foliage,.15 DAT ai/ha DAT DAT Tubers, 1.5 DAT ai/ha DAT DAT Foliage,.15 DAT ai/ha DAT DAT Pyridine- C-label Tubers,.15 DAT ai/ha DAT DAT Foliage,.15 DAT ai/ha DAT DAT Tubers, 1.5 DAT ai/ha DAT DAT Foliage,.15 DAT ai/ha DAT DAT DAT: days after treatment The triazine radiolabelled tuber extracts showed a complex mixture of aqueous soluble polar moieties separated into at least 11 fractions by reverse phase HPLC. Approximately % of the tuber TRR eluted in four early eluting HPLC regions. The largest early eluting HPLC region (T) was 1% to 15% TRR and was further characterised as a mixture of multiple components. In tubers the major metabolites identified were pymetrozine (14% TRR), GS-2199 (approximately 2% TRR) and its glycoside conjugate (5% TRR), CGA (12% TRR) and CGA (1% TRR). The major residues in foliage extracts were pymetrozine (9% TRR) and the glycoside of GS-2199 (916% TRR). ther identified components in the foliage were GS (12% TRR), CGA (12% TRR) and CGA (1% TRR). The pyridine radiolabelled residues from tubers were primarily identified as CGA96956 ( trigonelline, 545% TRR), monosaccharide conjugates of CGA-18 (1222% TRR), CGA- 18 (15% TRR), CGA-188 (< 2% TRR), CGA (approximately 1% TRR) and pymetrozine ( 2% TRR).

23 1611 The major residues in foliage were identified ascga96956 ( trigonelline, 6% TRR), CGA18 (< 1% TRR), CGA188 (< 2% TRR), glycoside conjugate of CGA12862 (11% TRR), CGA12862 ( 2% TRR) and pymetrozine (518% TRR). Table 24 Distribution of metabolites in potato tubers and foliage after application of [triazine-6- C]- pymetrozine at rates of.15 ai/ha Fraction Tuber Foliage day DAT day DAT 29 day DAT day DAT day DAT 29 day DAT % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ TRR Identified pymetrozine CGA & CGA5525 CGA GS GS2199 gluc Characterised T T T a T T T T T T T T T15.85 T T T T T T2 2. T T T T ther Unextracted MeH:H Reflux Final unextracted Total characterised Total identified a Characterised as multiple components

24 1612 Table 25 Distribution of metabolites in potato tubers and foliage after application of [triazine-6- C]- pymetrozine at rates of 1.5 ai/ha Fraction Tuber Foliage day DAT day DAT 29 day DAT day DAT day DAT 29 day DAT % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ TRR Identified pymetrozine CGA & CGA5525 CGA GS GS2199 gluc Characterised T T T a T T T T T T T T T15.8. T T T T T T T T T26.5 T ther Unextracted MeH:H Reflux Enzyme HCl Reflux Final unextracted Total characterised Total identified a Characterised as multiple components

25 161 Table 26 Distribution of metabolites in potato tubers and foliage after application of [pyridine-5- C]- pymetrozine at rates of.15 ai/ha Fraction Tuber Foliage day DAT day DAT 29 day DAT day DAT day DAT 29 day DAT % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ TRR Identified pymetrozine CGA CGA CGA18-gly CGA CGA CGA12862-gly Characterised P P P P.8. P P P P P P P P P P P P P P2...2 P28.2 ther Unextracted MeH:H Reflux Final unextracted Total characterised Total identified

26 16 Table 2 Distribution of metabolites in potato tubers and foliage after application of [pyridine-5- C]- pymetrozine at rates of 1.5 ai/ha Fraction Tuber Foliage day DAT day DAT 29 day DAT day DAT day DAT 29 day DAT % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ % TRR mg eq/ TRR Identified pymetrozine CGA CGA CGA18-gly CGA CGA CGA12862-gly Characterised P P P P P P1. P P P P.6 - P P P.9.1 P P P P P P2.9 2 ther Unextracted MeH:H Reflux Final unextracted Total characterised Total identified The storage stability of residues in potato matrices was investigated by re-analysing the samples after 1922 weeks. Recovered residues are presented in the following table.