Metabolism of [14C]parathion and [14C]paraoxon in isolated,perfused rat livers

Perfusion of ¹⁴C-(ring)-parathion or ¹⁴C-(ring)-paraoxon with blood through isolated, intact rat livers resulted in the rapid degradation of these insecticides. Degradation was negligible in the absence of rat liver (controls), thus demonstrating the capacity of the liver per se to effectively degrade these compounds. Of the total radiocarbon recovered after liver perfusion with [¹⁴C]parathion, 33 % could be attributed to unchanged [¹⁴C]parathion (similarly distributed between the liver and the blood) while 67.9 % was degraded to water soluble compounds and 2.5% was converted to organic soluble paraoxon and traces of p-nitrophenol. Nearly all of the [¹⁴C]paraoxon, however, was degraded by the intact rat liver, resulting in water soluble products that amounted to 98.5% of the total radiocarbon recovered. Unexplained losses of radiocarbon with the perfusion apparatus used were lower in the presence of rat liver which degraded the insecticides to more water soluble compounds. The water soluble degradation products produced from [¹⁴C]parathion and [¹⁴C]paraoxon were non-toxic to mosquito larvae (Aedes aegypti L.). These ring-labelled products were found to be conjugated p-nito-phenol. Nearly all of the water soluble radiocarbon was located in the perfused blood, while only small amounts (1.8 to 3.0% of recovered) were excreted via the bile or were associated with the liver tissue (1.3 to 1.8 % of recovered).     

Fate of [14C]diflubenzuron on cotton and in soil

Aqueous suspensions and oil emulsions of a commercial [¹⁴C]diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide) formulation (Dimilin W-25) remained on the leaf surface of greenhouse-treated plant tissues. Absorption, translocation, and metabolism of the [¹⁴C]diflubenzuron were not significant. Less than 0.05% of the applied ¹⁴C was found in newly developed plant tissues 28 days after spray treatment. [¹⁴C]Diflubenzuron was degraded in soil. After 91 days, biometer flask studies showed that 28% of the ¹⁴C incorporated into the soil as [¹⁴C]diflubenzuron was recovered as ¹⁴CO₂. Major dichloromethane-soluble soil residues were identified as unreacted [¹⁴C]diflubenzuron and [¹⁴C]4-chlorophenylurea. A minor unknown degradation product cochromatographed with 2,6-difluorobenzoic acid. Insoluble ¹⁴C-residues increased with time and represented 67.8% of the residual ¹⁴C in the soil 89 days after treatment. Cotton plants grown for 89 days in [¹⁴C]diflubenzuron-treated soil contained only 3% of the ¹⁴C applied to the soil. Small quantities of acetonitrile-soluble [¹⁴C]4-chlorophenylurea were isolated from the foliar tissues. Root tissues contained small amounts of [¹⁴C]diflubenzuron and trace quantities of a minor ¹⁴C-product that chromotographed similarly to 2,6-difluorobenzoic acid. Most of the ¹⁴C in the plant tissues (84–93%) was associated with an insoluble residue fraction 89 days after treatment.     

Studies on the mode of action of asulam,aminotriazole and glyphosate in Equisetum arvense L. (field horsetail). I: The uptake and translocation of [14c]asulam, [14C]aminotriazole and [14C]glyphosate

The uptake and translocation of [¹⁴C]asulam (methyl 4-aminophenyl-sulphonylcarbamate), [¹⁴C]aminotriazole (1-H-1,2,4-triazol-3-ylamine) and [¹⁴C]glyphosate (N-(phosphonomethyl)glycine) were assessed in Equisetum arvense L. (field horsetail), a weed of mainly horticultural situations. Under controlled-environment conditions, 21°C day/18°C night and 70% r. h., the test herbicides were applied to 2-month-old and 2-year-old plants. Seven days following the application of 0.07-0.09 °Ci (1.14mg) of the test herbicides to young E. arvense, the accumulation of ¹⁴C-label (as percentage of applied radioactivity) in the treated shoots, untreated apical and basal shoots was as follows: [¹⁴C]asulam, 13.2, 0.18 and 1.02%; [¹⁴C] aminotriazole, 67.2, 3.65 and 1-91%; [¹⁴C]glyphosate, 35.9, 0.06 and 0.11%. The equivalent mean values for the accumulation of ¹⁴C-label in 2-year-old E. arvense were [¹⁴C]asulam, 12.0, 1-15 and 1.74%; [¹⁴C]aminotriazole, 58.6, 9.44 and 4.12%; [¹⁴C]glyphosate, 33.1, 0.79 and 2.32%. In the latter experiment, test plants received 0.25-0.30 °Ci (4mg) of herbicide, they were assessed after a 14-day period and the experiment was carried out at 3-week intervals between 2 June and 25 August on outdoor-grown plants. Irrespective of test herbicide or time of application, very low levels of ¹⁴C-label accumulated in the rhizome system. Only 0.2% of the applied radioactivity was recovered in 2-year-old plants and 0.4% in 2-month-old plants. In the young plants [¹⁴C]asulam accumulated greater amounts and concentrations of ¹⁴C-label in the rhizome apices and nodes than [¹⁴C]aminotriazole or [¹⁴C]glyphosate treatments. Inadequate control of E. arvense under field conditions may be due to limited basipetal translocation and accumulation of the test herbicides in the rhizome apices and nodes.     

[14C]Dicofol association to cellular components of Azospirillum lipoferum

The bacterium Azospirillum lipoferum is able to survive in high concen-trations of the organochlorine acaricide dicofol [1,1-bis-(4-chlorophenyl)-2,2,2-trichloroethanol]. It accumulates this chemical in the cell envelope where it is protected against hydrolysis. We investigated the nature of cell envelope molecules with which [¹⁴C]dicofol is associated; no indication of [¹⁴C]dicofol–saccharide bonds was found. We concluded that about 80% of the total [¹⁴C]dicofol found in the cells was associated with lipids and the remaining 20% with proteins. Electrophoresis did not indicate any correlation of a specific protein band with [¹⁴C]dicofol radioactivity peaks. After Folch partition, [¹⁴C]dicofol distribution in TLC analysis showed 60% of [¹⁴C]dicofol–lipid bonds related to neutral lipids, 20% to phospholipids and the remaining 20% of the bonds associated with other lipids. Experimental results suggested that [¹⁴C]dicofol associates mainly with membrane domains near proteins and that this association influences membrane fluidity as well as enzymatic activity. © 1998 SCI     

DDT and pyrethroids: Receptor binding and mode of action in the house fly

The mode of action of DDT and pyrethroids was investigated in the house fly, Musca domestica L, using drug:receptor binding techniques. Both in vivo and in vitro binding studies demonstrated the existence of membrane receptors which bind specifically to [¹⁴C]DDT and [¹⁴C]cis-permethrin. The receptors show properties to be expected of a critical target site of these insecticides. These include negative temperature correlation with binding, relatively nonsensitivity to DDE, and sensitivity to Ca²⁺. The receptor sites are readily saturated at 45–90 nM [¹⁴C]DDT and have an apparent disassociation constant (K_d) of 12.2 nM. The maximum number of binding sites was estimated to be 17 pmol DDT/mg membrane protein (0.34 pmol/house fly head). Competition studies showed DDT, cis-permethrin, and cypermethrin bind to the same receptor but not at precisely the same site. The addition of Ca²⁺ to the incubation buffer significantly inhibited the binding of both [¹⁴C]DDT and [¹⁴C]cis-permethrin, suggesting the receptor binding is Ca²⁺ sensitive and may have a role in ion conductance.     

The metabolism of [14C] cymoxanil in the rat

A rat, given a single oral dose of [¹⁴C] cymoxanil, 1-(2-cyano-2-methoxyimino-[2-¹⁴C]-acetyl)-3-ethylurea, eliminated 91% of the radioactivity within 72 h. The urine contained 71%, the faeces 11%, and the expired air about 7% of the radiolabel; no ¹⁴C residue was found in the internal organs. Greater than 70% of the radioactivity in the urine was identified. The major metabolite was characterised as glycine, both free and conjugated, as hippuric acid and phenylaceturic acid [N-(phenylacetyl)-glycine], and probably in the form of polypeptides of low molecular weight. The other metabolites identified included 2-cyano-2-methoxyiminoacetic acid, 2-cyano-2-hydroxyiminoacetic acid and 1-ethylimidazolidine-2, 4, 5-trione. The minor metabolites included succinic acid and 2-oxoglutaric acid which indicated reincorporation of metabolic ¹⁴C. Cymoxanil, as such, was not detected in the urine.     

Uptake and distribution of [14C]metalaxyl by detached tobacco leaves

When the petioles of detached tobacco leaves (10–17 cm²) were incubated in aqueous solutions containing [¹⁴C]metalaxyl, uptake of the fungicide was dependent on the temperature and photoperiod. Detached leaves took up 78% more [¹⁴C]metalaxyl at 26°C than at 16°C. The rate of uptake in the light at 21°C was linear, but after an additional 20h in the dark, there was only twice as much fungicide in the leaves. Different sized leaves contained the same amount of fungicide per cm² area. Uptake by detached leaves of the ¹⁴C-labelled anilide lactones ofurace and RE-26940 [2-methoxy-N-(tetrahydro-2-oxo-3-thienyl)acet-2′,6′-xylidide] was similar to that of metalaxyl. At the concentration of metalaxyl (66 ng ml^?1) that controlled blue mould (Peronospora tabacina) on detached tobacco leaves, the amount of fungicide in the leaves was found to be 7.25 ng. Autoradiography showed that the distribution of [14C]metalaxyl in detached leaves after incubation for 23h was uniform, although higher concentrations of the label were present in the smaller veins of the leaves.     

Movement and metabolic fate of [14C]ethephon in flue-cured tobacco

The absorption, distribution, and metabolic fate of [¹⁴C]ethephon in flue-cured tobacco (Nicotiana tabacum L.) was studied using autoradiography, thin-layer chromatography, high-voltage paper electrophoresis, and liquid scintillation spectrometry. Labeled ethephon penetrated mature leaf tissue easily and was translocated primarily in an acropetal direction. No ¹⁴C activity was detected in any other plant part except the treated leaf. The first day after treatment, most of the translocated ¹⁴C was detected in the midrib, and after 2 days radioactivity was noticed in veinal areas distal to the point of application. Four days later, however, ¹⁴C was detected in slight amounts only in the midrib, indicating that [¹⁴C]ethephon was rapidly degraded by the leaf tissue. Depending on leaf position on the stalk, as much as 92% of the radioactivity had disappeared from the leaf tissue during the first day after treatment, and as little as 5% of the applied radioactivity was recovered 4 days later. Methanol-extracted plant residues contained insignificant amounts of ¹⁴C. All of the ¹⁴C in methanol extracts was present in the form of a labeled compound with an R_f value corresponding to that of ethephon, indicating the absence of any detectable metabolites of the parent compound. Smoke analysis of cigarettes showed that more [¹⁴C]ethylene than ¹⁴CO₂ was recovered in the main stream, whereas the trend was reversed in the case of side stream smoke.     

Studies on the mode of action of asulam,aminotriazole and glyphosate in Equisetum arvense L. (field horsetail). II: The metabolism of [14C]asulam, [14C]aminotriazole and [14C]glyphosate

The metabolism of [¹⁴C]asulam (methyl 4-aminophenylsulphonylcarbamate), [¹⁴C] aminotriazole (1H-1,2,4-triazol-3-ylamine) and [¹⁴C]glyphosate (N-(phosphonomethyl)glycine) were assessed in Equisetum arvense L. (field horsetail). Following application of the test herbicides (4mg?0.3 °Ci herbicide/shoot) to the shoots of 2-year-old pot-grown plants, the total recovery of ¹⁴C-label after 1 week and 8 weeks was high for all three herbicides (>80-0% of applied radioactivity). Asulam was persistent (>69-7% of recovered radioactivity) in both shoots and rhizomes. Sulphanilamide, a hydrolysis product of asulam, accounted for the remainder of the recovered radioactivity. Aminotriazole showed evidence of conjugation in shoots and rhizomes. The principal ¹⁴C-labelled component in shoots was composed of high proportions of aminotriazole (>76-3%) together with the metabolites: X (ninhydrin positive), β-(3-amino-1,2,4-triazolyl-1-)α-alanine, Y (diazotization positive) and various unidentified compounds. Rhizomes generally contained lower proportions of intact aminotriazole (>59.4%) together with the metabolites X,Y and unidentified compounds. The proportion of aminotriazole did not decrease with time in shoots or rhizomes; however, the ratio of metabolite X: Y moved in favour of Y as the interval after treatment increased. Glyphosate was extensively metabolised in shoots and rhizomes to yield aminomethylphosphonic acid (AMPA) and various unidentified compounds. Differential metabolism appears to be one of the factors which may govern the persistence and toxicity of the test herbicides in E. arvense.     

Distribution of the radioactivity in sugar beet plants treated with [14C]aldicarb

Sugar beet plants were grown in the field, after in-furrow application of [¹⁴C]aldicarb (3 kg of aldicarb ha^?1) at planting. Some plants (the growing plants) were harvested 99 days after sowing and the rest (the ripe plants) 196 days after sowing. The percentages of the weights of [¹⁴C]aldicarb equivalents (the total aldicarb plus aldicarb sulphoxide and sulphone, plus all the other metabolites of [¹⁴C]aldicarb which contain ¹⁴C, expressed as aldicarb equivalents) incorporated into the beet plants, relative to the weight applied to the soil, were 2.8 and 1.8, respectively for the growing and ripe plants. The concentrations of [¹⁴C]aldicarb equivalents (mg kg^?1 fresh weight) in the growing and ripe plants, respectively were: blades of the external leaves, 3.16 and 0.93; blades of the internal leaves, 0.63 and 0.68; petioles of the external leaves, 0.51 and 0.26; petioles of the internal leaves, 0.15 and 0.05; crowns, 0.14 and 0.15; roots, 0.16 and 0.13. The proportions of the extractable aldicarb plus aldicarb sulphoxide and aldicarb sulphone determined by gas-liquid chromatography (expressed as aldicarb equivalents) relative to [¹⁴C]aldicarb equivalents, in the external and internal leaf blades of the growing beets, were 56 and 60%, respectively; these values declined to 25 and 19%, respectively in the ripe plants. The proportion was 21 % or less in all other parts of the growing and ripe plants.     

A comparison of DDT and its biodegradable analogues tested on ATPase enzymes in cockroach

Analogues of DDT (ethoxymethyl and methoxymethio derivatives) compared with DDT for their inhibitory action on the ATPase system from tissues of the cockroach, Periplaneta americana show similar, but less inhibitory effects. The mitochondrial (oligomycin-sensitive) Mg²⁺ ATPase activity from coxal muscle preparations was more sensitive to DDT than the two analogues; whereas, the muscle and nerve cord homogenates showed about equal sensitivity to the biodegradable analogues. The mitochondrial Mg²⁺ ATPase from nerve cord preparation was more sensitive to the three compounds than the Na⁺K⁺ ATPase activity. The significance of these results in relation to recent reports on the effect of DDT on Na⁺K⁺ ATPase is discussed.     

The sensitivity of mitochondrial Mg2+ ATPase to DDT and analogs at different temperatures

Oligomycin-sensitive (O-S) Mg²⁺ ATPase from American cockroach muscle was more sensitive to DDT, TDE, methoxychlor, and DDE at cool temperatures than at warm temperature, thus showing a negative temperature effect. In contrast, inhibition by acaricides dicofol, chlorfenethol, and Plictran shows a positive temperature effect. Oxidative phosphorylation in a mitochondrial preparation from cockroach coxal muscle was reduced by DDT, but the reduction was greater at a higher temperature (32°C) than at a cooler temperature (22°C). In addition, Na⁺K⁺ ATPase from cockroach nerve cord showed a positive temperature effect with DDT. The inhibition by DDT was much less on Na⁺K⁺ ATPase than on O-S Mg²⁺ ATPase. The negative temperature effect by DDT and analogs on O-S Mg²⁺ ATPase parallels toxicity effects on insects and fish as reported by numerous researchers. The results provide further evidence for this energy-regulating enzyme being a critical component in the biological action of DDT.     

Mineralization of [14C] glyphosate and its plant-associated residues in arable soils originating from different farming systems

The biomineralization of [¹⁴C]glyphosate, both in the free state and as ¹⁴C-residues associated with soybean cell-wall material, was studied in soil samples from four different agricultural farming systems. After 26 days, [¹⁴C]carbon dioxide production from free glyphosate accounted for 34–51% of the applied radiocarbon, and 45–55% was recovered from plant-associated residues. For three soils, the cumulative [¹⁴C]carbon dioxide production from free glyphosate was positively correlated with soil microbial biomass, determined by substrate-induced heat output measurement and by total adenylate content. The fourth soil, originating from a former hop plantation, and containing high concentrations of copper from long-term fungicide applications, did not fit this correlation but showed a significantly higher [¹⁴C]carbon dioxide production per unit of microbial biomass. Although the cumulative [¹⁴C]carbon dioxide production from plant-associated ¹⁴C-residues after 26 days was as high as from the free compound, it was not correlated with the soil microbial biomass. This indicates that the biodegradation of plant-associated herbicide residues, in contrast to that of the free compound, involves different degradation processes. These encompass either additional steps to degrade the plant matrix, presumably performed by different soil organisms, or fewer degradation steps since the plant-associated herbicide residues are likely to consist mainly of easily degradable metabolites. Moreover, the bioavailability of plant-associated pesticide residues seems to be dominated by the type and strength of their fixation in the plant matrix. ©1997 SCI     

Degradation of [14C]Terbuthylazine and [14C]Atrazine in Laboratory Soil Microcosms

The degradation and formation of major chlorinated metabolites of terbuthylazine and atrazine in three soils (loamy clay, calcareous clay and high clay) were studied in laboratory experiments using molecules labelled with ¹⁴C on the s-triazine ring. Soil microcosms were treated with the equivalent of 1 kg ha^-1 of herbicide and incubated in the dark for 45 days at 20(±1)°C. The quantity of [¹⁴C]carbon dioxide evolved in the soils treated with atrazine was negligible and could not be attributed to mineralization of the parent molecule. The mineralization of terbuthylazine accounted for 0·9–1·2% of the initial radioactivity. In the soils studied, the extrapolated half-lives varied from 88 to 116 days for terbuthylazine and 66 to 105 days for atrazine, with no significant differences for the three soils and the two molecules. The deethyl metabolites of the two s-triazines and the deisopropyl-atrazine metabolite appeared during the incubation in the three soils. The completely dealkylated metabolite was not detected in any of the soils. After 45 days of incubation, the non-extractable soil residues for the high clay, loamy clay and calcareous clay soils represented for terbuthylazine, 33·5, 38·3 and 43·1% and for atrazine, 19·8, 20·8 and 22·3% of the initial radioactivity. © 1997 SCI.     

Metabolism of [14C]cymoxanil in grapes,potatoes and tomatoes

Foliar-applied [¹⁴]cymoxanil, 1-(2-cyano-2-methoxyimino-[2-¹⁴C]acetyl)-3-ethylurea was rapidly metabolised in grapes, tomatoes and potatoes, Furthermore, the metabolism of this fungicide was unusual in that the metabolites were found to be naturally occurring compounds, with glycine as the major metabolite. Significant levels of radioactivity were found in other amino-acids, sugars, starch, fatty acids and lignin, indicating incorporation of carbon-14 via the various metabolic pathways.     

Distribution and metabolic fate of [14C]-daminozide injected into silver maple and american sycamore seedlings

The distribution and metabolic fate of [¹⁴C]-daminozide in silver maple and American sycamore seedlings were studied by use of autoradiography, ion-exchange chromatography, thin-layer chromatography (t.l.c.), and liquid scintillation spectrometry. Within one day after treatment with [¹⁴C]-daminozide, radioactivity was detected in all parts of the plant. The ¹⁴C concentrated in meristematic regions of the leaves. Ion-exchange and thin-layer chromatographic analyses of the 50% methanol extracts indicated that no detectable metabolites of daminozide were formed in any of the plant parts but approximately 20% of the applied ¹⁴C, most of it in the stem tissue, was not extractable by aqueous methanol.     

Effects of insecticides and GABAergic agents on a house fly [35S]t-butylbicyclophosphorothionate binding site

Specific binding of [³⁵S]t-butylbicyclophosphorothionate ([³⁵S]TBPS) to a house fly thorax-plus-abdomen membrane preparation at 20°C is characterized by apparent K_d and B_max values of 0.21 μM and 2.5 pmol/mg protein, respectively, an association half-time of 13 min at 2 nM, and a biphasic dissociation curve showing half-times of 15 and 35 min. Specific binding is reduced at 37°C apparently due to instability of the receptor-ligand complex and at 0°C as the result of very slow association. [³⁵S]TBPS binding is diminished by detergents, stimulated by GABA at low ligand concentration, and inhibited by picrotoxinin and certain barbiturates, benzodiazepines, bicyclophosphorus compounds, and polychlorocycloalkane insecticides. The potency of TBPS and three related phosphorothionates in displacing [³⁵S]TBPS parallels their toxicity on injection into house flies; the corresponding bicyclophosphates are less active in both assays. Cyclodienes of low toxicity are generally poor inhibitors of radioligand binding. α-Endosulfan and syn-12-hydroxyendrin are more potent than their β and anti isomers, respectively, both as inhibitors of TBPS binding and as toxicants. Analysis of Scatchard plots indicates that picrotoxinin and heptachlor epoxide are non-competitive inhibitors of [³⁵S]TBPS binding. The [³⁵S]TBPS binding site of the house fly membrane preparation differs from that extensively studied in mammalian brain with respect to their responses to many insecticides and GABAergic agents.     

Biliary secretion of 14C and identification of 5,6-dihydro-5,6-dihydroxycarbaryl glucuronide as a biliary metabolite of [14C]carbaryl in the rat

The biliary secretion of ¹⁴C was observed in conscious, bile-fistulated rats given single oral doses of [¹⁴C]carbaryl (1.5, 30, and 300 mg/kg). Over 94% of the ¹⁴C was absorbed after 12 hr. From 15 to 46% of the ¹⁴C was secreted in bile, 10–40% in urine, and less than 1% in feces 12 hr after dosing. Three metabolites were isolated from bile and identified by mass and/or NMR spectrometric methods. These metabolites were: 5,6-dihydro-5,6-dihydroxycarbaryl glucuronide (12–18% of the biliary ¹⁴C), a conjugate(s) of carbaryl (12% of the biliary ¹⁴C), and conjugated isomers of hydroxy-carbaryl (2% of the biliary ¹⁴C). The majority of the biliary ¹⁴C remains to be identified.     

Metabolism of [C]vernolate in soybeans

Penetration and metabolism of [¹⁴C]vernolate in soybean [Glycine max (L.) Merr. var Ransom] pods and seeds were measured 0, 1, 4, 24, 48, or 72 hr after treatment which occurred at 40 days after flowering. Total ¹⁴C recovery decreased ca. 50% within 4 hr and the loss of ¹⁴C was considered to be a measure of volatility. Total nonpolar extractants decreased in a logarithmic pattern which approached 10% of total ¹⁴C recovered within 24–48 hr. Total polar extractants increased in a logarithmic pattern to a maximum of 90% of total ¹⁴C recovered within 24 hr. Seed nonpolar extractants never exceeded 2% of the total ¹⁴C recovered while pod nonpolar extractants consisted of vernolate plus an unidentified component that did not thin-layer chromatograph (TLC) as the sulfone or sulfoxide. Pod polar extractants increased with time to ca. 75% of the total ¹⁴C recovered (24–48 hr) and decreased to ca. 58% at 72 hr after treatment. Seed polar extractants averaged ca. 10% of total ¹⁴C recovered for the first 48 hr after treatment and then increased to 30% of total ¹⁴C recovered. Thus, [¹⁴C]vernolate per se concentration decreased to <1% of applied material within 72 hr through volatilization and degradation of nonpolar extractants to polar products. Polar metabolites showed two major patterns of vernolate detoxification. One detoxification system produced ¹⁴C-metabolites whose R_f's were equivalent to that reported in corn (Zea mays L.) [J. P. Hubbell and J. E. Casida, [J. Agric. Food Chem. 25, 404 (1977)] and accounted for <30% of the pod polar extractants. A second detoxification system was most prevalent in soybean pod and seed tissues and resulted in very rapid modification of vernolate with an unidentified product that was 85% of the extracted ¹⁴C within 4 hr after treatment and which decreased in concentration with time. Therefore, unexplained vernolate detoxification system(s) exist in soybean pod and seed.     

The metabolism of [14C]aldicarb in the leaves of sugar beet plants

Sugar beet plants were grown in the field, after in-furrow application of [¹⁴C]aldicarb (3 kg of aldicarb ha^?1) at planting. The ripe sugar beet plants were harvested, and the blades and petioles of the leaves were analysed separately. In the whole leaves, 15% of the ¹⁴C (all the percentages of ¹⁴C are relative to the total ¹⁴C incorporated into the whole leaves) was insoluble in ethanol+ water (1+1 by volume), 31% was organo-soluble (and thus unconjugated in the leaves), and 54% was water-soluble (mainly conjugated to plant constituents). The weights and concentrations (as aldicarb equivalents) of various identified metabolites of aldicarb, incorporated into the leaves, were determined; no aldicarb, as such, was detected.