Atrazine Degradation Products Research Articles

Immunochemical Techniques and Immunosensors for the Analysis of Dealkylated Degradation Products of Atrazine

Abstract Two different immunoassay (IA) formats for pesticide residue analysis, a field format (dipstick IA) and an automated version (flow injection immunoanalysis, FIIA), are described with regard to method development and validation performed by measuring water, soil, and liquid food samples and comparing the results with the respective GC data obtained. As representative analyte a pesticide metabolite, deethylatrazine as the major atrazine metabolite, was selected. The measuring range for deethylatrazine was from 0.1–10 μg/L with the dipstick IA and from 0.01–10 μg/L with the FIIA. With both formats, water and liquid food samples can be measured directly without the need for any prior enrichment or clean-up steps. In the case of the soil samples, two extraction steps can be omitted as compared to extract preparation for GC analysis which usually takes further 3–4 h. A close correspondence was found between the results of the two immunoassay formats and GC measurements.

Analytical performance testing of an atrazine immunoassay system.

A rigorous performance evaluation of an enzyme immunoassay (EIA) kit for the determination of atrazine in water samples was undertaken. Eleven individual batches of samples containing standards and spiked drinking waters were analysed and precision, bias and limit of detection were measured using statistical analysis. The technique was shown to be capable of achieving performance criteria (a total standard deviation of less than 5% or 2.5 ng, whichever is the greater) demanded of modern analytical systems and achieved a limit of detection of 9.2 ng l-1. There was no statistically significant bias measured for drinking water samples. Interference tests showed that the atrazine immunoassay was not significantly affected in the pH range 4.0-8.0 or by drinking water matrix components (anions, cations and chlorination by-products), even at their maximum allowable concentrations. There was a small extent of cross-reaction with simazine and atrazine degradation products, but given the persistence of atrazine, through its resistance to hydrolysis, breakdown products are likely to be present at much lower concentrations than the parent compound in drinking water. Simazine may potentially be more problematic, so it would be prudent to monitor a proportion of samples for simazine to determine the extent to which this may be contributing to the 'atrazine' measured in drinking water samples using the EIA kit.

Adsorption of atrazine, simazine, and glyphosate in soils of the Gnangara Mound, Western Australia

Sandy soils were sampled from second rotation sites of Pinus pinaster Ait. on the Gnangara Mound in Western Australia. Adsorption isotherms were measured for atrazine [6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine], simazine [6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine], and glyphosate [N-phosphonomethyl-aminoaceticacid]. Adsorption isotherms were also measured for degradation products of atrazine: hydroxyatrazine [6-hydroxy-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine] (HA), desethylatrazine [6-chloro-N-isopropyl-1,3,5-triazine-2,4-diamine] (DEA); and of glyphosate: aminomethylphosphonic acid (AMPA). The adsorption of the 2 triazines was proportional to soil organic carbon content and was not affected significantly by other soil parameters. The affinity for soil organic carbon was in the order atrazine = simazine = DEA > HA. Affinity of atrazine for the type of organic matter in the Gnangara Mound soils (expressed as Koc) was significantly greater than is commonly reported for other soils. The adsorption of glyphosate and AMPA increased strongly with iron and aluminium content of soils and decreased with increasing soil organic carbon content. This would indicate that glyphosate and AMPA are mainly adsorbed by clay minerals, while soil organic matter competes for adsorption sites and inhibits adsorption. Contrary to what is usually reported for batch adsorption of pesticides in soils, significant increases in adsorption of the triazines and glyphosate were measured after 1 day of equilibration.

Hydroxylated Atrazine Degradation Products in a Small Missouri Stream

This research assessed the occurrence of hydroxylated atrazine degradation products (HADPs) in streamwater from Goodwater Creek watershed in the claypan soil region of northeastern Missouri. Streamwater was sampled weekly from June 1992 to December 1994 at a V-notch weir used to measure streamflow for this 7250-ha watershed. Filtered water samples were prepared by cation exchange solid-phase extraction and analyzed for hydroxyatrazine (HA), deethylhydroxyatrazine (DEHA), and deisopropylhydroxyatrazine (DIHA) by high-performance liquid chromatography with UV detection. HADPs were confirmed by mass spectrometry and an alternative HPLC/UV method. Frequency of HADP detection was 100% for HA, 25% for DEHA, and 6% for DIHA. Concentrations ranged from 0.18 to 5.7 μg L -1 for HA, from <0.12 to 1.9 μg L -1 for DEHA, and from <0.12 to 0.72 μg L -1 for DIHA. These results establish that HADPs can contaminate surface water and that HA contamination of surface water is a significant fate pathway for atrazine in this watershed.

Comparison of sorbents for the solid-phase extraction of the highly polar degradation products of atrazine (including ammeline, ammelide and cyanuric acid)

Three different types of non-polar sorbents, i.e., C 18 silica, apolar styrene-divinylbenzene copolymer (PRP-1) and porous graphitic carbon (PGC), were compared for the solid-phase extraction of atrazine, simazine and nine degradation products obtained by dealkylation, dehalogenation, hydroxylation or deamination mechanisms. The C 18 silica was shown to be effective only for the first degradation products (deethyl-, deisopropyl- and hydroxyatrazine), the others being too polar. Despite a higher retention provided by PRP-1, the retention of the hydroxy-dealkylated derivatives is too low to allow the handling of a sufficiently large volume for determinations below the μg/l level. The more polar derivatives, i.e., ammeline, ammelide and cyanuric acid, are not retained by either C 18 silica or PRP-1, whereas the capacity factor measured on a PGC column eluted with water was above 100. The conditions of extraction and elution using a cartridge packed with 500 mg of PGC are described for all the series of compounds and recoveries above 90% were obtained from 500-ml samples. The analytical separation was carried out using a C 18 silica column and confirmation was obtained using a PGC column. Determinations of the degradation products in real samples are presented with detection limits below the 0.1 μg/l level.

Identification of Fenton's reagent‐generated atrazine degradation products by high‐performance liquid chromatography and megaflow electrospray ionization tandem mass spectrometry

AbstractHigh‐performance liquid chromatography megaflow electrospray tandem mass spectrometry (HPLC/ES‐MS/MS) with an on‐line radioisotope detector was used to identify [2,4,6‐14C] atrazine degradation products generated by treatment with Fenton's reagent (Fe2+ and H2O2). Fenton's reagent produced dealkylated and/or partially oxidized [2,4,6‐14C] atrazine products in preference to dechlorinated products. Seven major products were identified by collision‐induced dissociation spectra: 4‐acetamido‐2‐chloro‐6‐(isopropylamino)‐s‐triazine, 4‐amino‐2‐chloro‐6‐(isopropylamino)‐s‐triazine, 4‐acetamido‐2‐chloro‐6‐(ethylamino)‐s‐triazine, 6‐amino‐2‐chloro‐4‐(ethylamino)‐s‐triazine, 4‐acetamido‐6‐amino‐2‐chloro‐s‐triazine, 2‐chloro‐4,6‐diamino‐s‐triazine and the first report of 4‐acetamido‐2‐hydroxy‐6‐(isopropylamino)‐s‐triazine. HPLC/ES‐MS/MS provided a rapid method for identifying a wide range of atrazine transformation products in aqueous samples and obviated the need for fraction collection, extraction, and chemical derivatization of the more polar atrazine products. Furthermore, because analyte retention times in HPLC/UV and HPLC/ES‐MS/MS were similar, compound identities determined using the latter could be directly assigned to peaks in UV chromatograms.

A polarographic investigation on interactions between cu(ii) ions and natural degradation products of a herbicide atrazine

AbstractA study was performed to investigate the possible formation of coordination compounds between Cu(II), Cd(II), Zn(II), and Pb(II) ions and natural degradation products of atrazine (ATR) desisopropylatrazine (DIA), desethylatrazine (DEA), and desethyldesisopropylatrazine (DEIA), as well as parent compound ATR itself and the related s‐triazine herbicide prometryne (PRO). By using polarographic and voltammetric titrations of a metal ion with a ligand and vice versa, at mercury drop or plain carbon paste electrode, only a formation of coordination compounds involving Cu(II) ions, of a type CuL2 (L = DEA, DIA, and PRO) and CuL (L = DEIA) in aqueous solutions at pHs above 4, were observed. By applying an indirect polarographic method with ligand exchange (EDTA), a conditional stability constant of CuDEIA was determined, and the value β CcuDEIA = 12.7 was obtainted.

Analysis of Hydroxylated Atrazine Degradation Products in Water Using Solid-Phase Extraction and High-Performance Liquid Chromatography. [Erratum to document cited in CA120:238106

Analysis of Hydroxylated Atrazine Degradation Products in Water Using Solid-Phase Extraction and High-Performance Liquid Chromatography. [Erratum to document cited in CA120:238106

Analysis of Hydroxylated Atrazine Degradation Products in Water Using Solid-Phase Extraction and High-Performance Liquid Chromatography

The fate of hydrowylated atrazine degradation products (HADPs) has not been studied extensively in aquatic environments because there are no published quantitative analytical methods that do not use radioisotopes. This paper presents a new method that has been developed to analyze these degradation products in water. Three HADPs, hydroxyatrazine (HA), deethylhydroryatrazine (DEHA), and deisopropylhydroryatrazine (DIHA), were extracted, concentrated, and purified from spiked (1 or 5 ppb) laboratory water and stream water samples (0.25 L) using SCX (propylbenzenesulfonic acid) cation-erchange, solid-phase extraction columns

Seasonal dynamics of atrazine in three soils under outdoor conditions

The fate of 14C labelled atrazine was followed in the first centimeters of soil throughout one year in a microlysimeter experiment under outdoor conditions. Leaching of atrazine reached 40 to 60 % and depends on the soil type and soil structure. As a whole, the pool of reversibly adsorbed residues decreased with time from 100 to less than 5 %, according to the rainfall distribution. Hydroxyatrazine was the main degradation product of atrazine and was preferentially adsorbed rather than leached in the three soils studied. Bound atrazine residues were formed from the first 45 days and their amount increased in the order : pelosol < brown soil < rendzina according to the soil organic matter content. These residues were involved in partial degradation processes after 180 days.

Trace-Level Determination Of Hydroxyatrazine And Dealkylated Degradation Products Of Atrazine In Waters

Abstract Dealkylated degradation products of atrazine, dealkyl- and deisopropyl-atrazine have been now detected in environmental waters, but determination of hydroxyatrazine has not been reported just because this product is not amenable to GC-MS. An analytical procedure has been developed for the simultaneous trace-level determination of some widely used chorotriazines and of three main degradation products, deisopropyl-, deethyl- and hydroxyatrazine, using a selective solid-phase-extraction coupled on-line to liquid chromatography. The preconcentration has been carried out with two precolumns in series. The first one, packed with the PRP-1 sorbent allowed the preconcentration of hydroxyatrazine and other metabolites. Analytes of interest were then desorbed from the PRP-1 precolumn in their ionic form and transferred to a second precolumn packed with a cation exchanger, which was afterwards coupled on-line to an analytical C18 column. The use of the selective cation-exchanger sorbent for the preconcentra...

Fate of major degradation products of Atrazine in Iowa soils

Abstract Five Iowa soils, sampled at two depths each were treated with 14C‐deethylatrazine (DEA) and 14C‐hydroxyatrazine (HYA) and incubated for nine and 17 weeks. 14CO2 evolution was monitored over this period. The degradation of DEA was influenced by both soil type and soil depth. For each soil studied, the degradation of DEA was much higher in the surface layer compared to the respective subsurface layer. The major degradation products from DEA included CO2, soil bound residues, and polar metabolites. Deethylhydroxyatrazine (DEHYA) and didealkylatrazine (DAA) were detected in minor quantities. Increased mineralization of DEA in the extended incubations confirmed the susceptibility of DEA to microbial degradation. In the complete metabolism studies with HYA, the major components identified included HYA, soil bound residues, and CO2. Deethylhydroxyatrazine deisopropylhydroxyatrazine and ammeline were found in smaller quantities. The relatively long persistence (45 to 69% remaining) of HYA was observed in 3 of the topsoils. HYA persisted well in all of the subsurface layer. There was no evidence of HYA forming significant amounts of bound residues.

Formation and Transport of Deethylatrazine in the Soil and Vadose Zone

AbstractAtrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine) and two degradation products were monitored at seven depths in the soil and vadose zone throughout the growing season in two experimental plots in which corn (Zea mays L.) was grown. The soils in these plots were a Kimo silty clay loam (clayey over loamy, montmorillonitic, mesic, Fluvaquentic Hapludoll) and a Eudora silt loam (course, silty, mixed, mesic, Fluventic Hapludoll). The purpose this field study was to identify and quantify the mobile and persistent degradation products of atrazine that comprise the input, or “source term,” to groundwater resulting from the application of atrazine to the soils. The formation of deethylatrazine (2‐amino‐4‐chloro‐6‐isopropylamino‐s‐triazine) and deisopropylatrazine (2‐amino‐4‐chloro‐6‐ethylamino‐s‐triazine) was monitored at vurious depths using suction lysimeters to determine the relative proportions at which these compounds enter the aquifer. Deethylatrazine was the major degradation product of atrazine identified in the soil water and appeared to enter the underlying aquifer at a concentration of 5.0 µg/L, which was greater than the concentration of atrazine entering the aquifer. Deisopropylatrazine also was detected in the soil water, bnt only in minor concentrations relative to atrazine and deethylatrazine. Because deethylatrazine was the major degradation product in the unsaturated zone, the deethylatrazine‐to‐atrazine ratio (DAR) may be a good indicator of transport of atrazine through the soil. The hypothesis is proposed that the DAR may be used to distinguish point‐source from nonpoint‐source contamination of an aquifer.

Uptake and Photosynthetic Inhibition by Atrazine and its Degradation Products on Four Species of Submerged Vascular Plants

AbstractThe photosynthetic inhibitory effect of atrazine (2‐chloro‐4‐ethylamino‐6‐isopropyl amino‐1,3,5‐triazine) and three of its major metabolites (deethylated, deisopropylated, and hydroxyatrazine) were determined for four species of submerged macrophytes: Potamogeton perfoliatus L., Ruppia maritima L., Myriophyllum spicatum L., and Zannichellia palustris L. The four species showed a similar response to varied dosages of the parent atrazine compound with an average I1 (concentration at which photosynthesis is inhibited by 1%) for the four species of 20 µg/L and an average I50 (concentration at which photosynthesis is inhibited by 50%) for the four species of 95 µg/L. The three major degradation metabolites of atrazine produced varying degrees of photosynthetic inhibition in the four species, but generally the order of toxicity was deethylated &gt; deisopropylated &gt; hydroxyatrazine with hydroxyatrazine causing an apparent stimulation of photosynthesis in several species. Of four species tested, Myriophyllum spicatum L. was the most resistant to atrazine and its metabolites. The magnitude of the actual uptake of the compounds [µg compound/grams dry wt (gdw) plant] by the plants correlated closely with the photosynthetic inhibitory response, i.e., at the same concentration the uptake of atrazine &gt; deethylated &gt; deisopropylated &gt; hydroxyatrazine. Considering that an extremely high environmental concentration (0.5 mg/L) of deethylated atrazine for an estuary only produced a photosynthetic inhibition of from 20 to 40% in four major species of submerged macrophytes, it is concluded that the degradation products of atrazine tested did not play a major role in the disappearance of the submerged vascular plants from the Chesapeake Bay.

Extraction and identification of a new degradation product of atrazine in the soil

AbstractGas‐chromatographic analyses of extracts of soil samples from plots, treated with a 50% atrazine wettable powder at dose rates of 2 and 4 kg a.i. ha−1, showed the presence of a new atrazine degradation product. This product was isolated, concentrated and purified by column chromatography and high‐performance liquid chromatography. The chromatographic properties of this material were identical with those of a product isolated from a 0.02% methanolic solution of 2‐amino‐4‐chloro‐6‐isopropyl‐amino‐1,3,5‐triazine that had been stored under laboratory conditions. A combined gas‐liquid chromatographic/mass spectrometric assay identified the new product in soil as 2‐isopropylamino‐4‐methoxy‐6‐methylamino‐1,3,5‐triazine.

Degradation of atrazine by soil fungi

Degradation of 14C-ethylamino-, and 14C-ring-labeled atrazine (2-chloro-4-ethylamino-6-isopropylamino- s-triazine) by pure cultures of several soil fungi was observed. Soil fungi that degraded atrazine, in a basal salts medium supplemented with sucrose, included: Aspergillus fumigatus Fres.; A. ustus (Bainier) Thorn and Church; A. flavipes (Bainier and Sartory) Thorn and Church; Rhizopus stolonifer (Ehr. ex Fr.) Lind.; Fusarium moniliforme Sheld.; F. roseum Lk. ex Fr. emend. Snyder and Hansen; F. oxysporum Schlecht.; Penicillium decumbens Thorn; P. janthinellum Biourge; P. rugulosum Thorn; P. luteum Zukal; and Trichoderma viride Pers. ex Fr. Although all of the fungi were able to degrade atrazine by N-dealkylation of either alkylamino group, both quantitative and qualitative differences in atrazine degradation occurred. 14CO 2 evolution occurred only from inoculated culture solutions containing chain-labeled atrazine. Chromatographie analysis of both ring- and chain-labeled atrazine culture solution revealed that atrazine was metabolized to two or more degradation products. Atrazine degradation products identified included 2-chloro-4-amino-6-isopropylamino- s-triazine and 2-chloro-4-ethylamino-6-amino- s-triazine.

Effects of Atrazine and Hydroxyatrazine on Nitrogen Metabolism of Selected Species

In field, soil culture, and nutrient culture experiments, 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) increased percent total nitrogen in all species studied, whether resistant, intermediate, or susceptible to 1 lb/A of atrazine. However, nitrogen content per plant was either unaffected or decreased by these atrazine treatments. One lb/A of atrazine increased percent protein and nitrate nitrogen in most species studied. Atrazine susceptibility apparently was related to its effect on percent non-protein and ammonia in the species tested. One lb/A of atrazine had no effect on percent non-protein nitrogen and decreased percent ammonia nitrogen in resistant species but increased both fractions in intermediate and susceptible species. One lb/A of 2-hydroxy-4-ethylamino-6-isopropylamino-s-triazine (hereafter referred to as hydroxyatrazine), a degradation product of atrazine, had no consistent effect on any nitrogen fraction studied.