Hanna Barchanska

Degradation study of mesotrione and other triketone herbicides on soils and sediments

PurposeTriketone compounds are considered to be less stable in the ecosystems in comparison with other herbicides. However, their degradation processes in environment are under investigation as both parents and degradation products can exhibit toxicity on non-target organisms. The objective of this research was to investigate the degradation of triketone herbicides: mesotrione, sulcotrione, and tembotrione, as well as their degradation products in soils and sediments.Materials and methodsThe degradation studies were conducted in soil and sediment samples with different physicochemical properties. All experiments were conducted under standard experimental conditions; therefore, it was possible to assess the influence of pH, organic carbon (OC) content of soils and sediments, and the sunlight on the stability of triketones and their degradation products. The conditions of extraction and chromatographic determination were optimized for the determination of triketones and their degradation products in laboratory-spiked sediment and soil samples.Results and discussionThe triketone degradation products exhibited higher stability in soil and sediment samples in comparison with parent herbicides. Soil microorganisms accelerated the degradation of all investigated compounds. In alkaline soil and sediments, all analytes exhibited higher stability in comparison with the acidic sorbents. The influence of OC content in sorbents was not evident. Photodegradation was the main path of triketones decomposition in soils and sediments.ConclusionsSince the stability of triketone herbicides may be significant, depending on the environmental conditions, the monitoring of the concentration of these compounds and in particular their degradation products should be conducted under the field conditions.

Rapid determination of mesotrione, atrazine and its main degradation products in selected plants by MSPD – HPLC and indirect estimation of herbicides phytotoxicity by chlorophyll quantification

A matrix – solid phase dispersion coupled with high-performance liquid chromatography (MSPD – HPLC) method was developed for the isolation and determination of mesotrione, atrazine as well as its degradation products: hydroxyatrazine, deisopropylatrazine, desethyldesisopropylatrazine and deethylatrazine in plant. The method was applied to monitor not only herbicide accumulation levels but also the influence of herbicides accumulation on chlorophyll concentration in crops popular in moderate climate: rape (Brassica napus), radish (Raphanus sativus), carrot (Daucus carota), parsley (Petroselinum sativum), weeds: grass (Gramineae Juss), chamomile (Chamaemelium nobile), thistle, (Carduus L.) and an aquatic plant hornwort (Ceratophyllum demersum L.). Chlorophyll was chosen as a biomarker of plant exposure to triazine and triketone herbicides because these compounds disturb the synthesis of chlorophyll that leads to reduction of this pigment content in plant tissues, which is manifested by whitening of the leaves and finally necrosis of a plant. The MSPD technique coupled with the HPLC–DAD lowers the detection limit of the aforementioned compounds below their maximum residual level (MRLs) 10 ng/g, according to European Union (Commission Regulation No 822/2009), the limits of quantitation (LOQ) were in the 1.0–3.0 ng/g range, while the recovery of analytes was 67–95%. All investigated herbicides turned out to be toxic for the considered terrestrial plant species. The herbicides at concentration of 100 ng/L, the maximum allowable concentration (MAC) in drinking water (Directive 98/83/EC), were innocuous for hornwort, an aquatic plant.

Monitoring of atrazine in milk using a rapid tube-based ELISA and validation with HPLC

Although atrazine has been banned in the European Union since 2007 it still persists in soil from where it can enter the food chain. Milk-producing animals accumulate atrazine from contaminated feed and water and since large quantities of milk and milk products are consumed its quality should be constantly monitored. The objective of this investigation was to develop a simple tube ELISA procedure suitable for use in non-specialised laboratories and in the field. A polyclonal antibody raised in sheep and the hapten-gelatine conjugate was immobilised onto polystyrene tubes. This enables the colour produced to be read on a basic spectrophotometer. Milk samples were collected from three farms in different regions of Poland and diluted before immunoassay was performed. Samples were extracted with hexane-acetone for HPLC analysis. The amount of fat in the milk samples interferes with the dose response so it essential that the standards are prepared in the same samples matrix. A good correlation between 1% and 2% was found between the two methods in the analysis of real samples. However the ELISA procedure was more sensitive that the HPLC method since atrazine was detected in some samples by the ELISA but was not confirmed by the HPLC method. The study demonstrated that the simple antigen-coated tube assay provides a cost effective and valuable screening test that can be easily modified for direct use as a screening tool in the field.

Simultaneous Determination of Selected Insecticides and Atrazine in Soil by Mae–GC–ECD

Abstract The procedure for simultaneous extraction from soil and determination by means of GC-ECD insecticides: aldrin, dieldrin, endrin and herbicide: atrazine was worked out. The proposed GC-ECD technique provides limits of detection in range 12 μg/mL - 18 μg/mL and 2 μg/mL, for insecticides and atrazine, respectively. Two different types of extraction: microwave assisted extraction (MAE) and ultrasound assisted extraction (UAE) with different solvents were tested to choose the procedure that provides the highest recoveries of analytes and low detection limits, typical for trace analysis (100 ppm or 100 mg/g, IUPAC). On the basis of recoveries and precision both extraction methods were compared. The insecticides recovery from soil samples obtained by UAE were in range 40-85%, coefficient of variation (CV): 1.3-5.0%, whereas for atrazine recovery was below 15% (CV: 8-18%). The most efficient and precise extraction procedure turned out to be MAE with n-hexane: acetone. The recoveries were in range 70-85% for insecticides and 84% for atrazine, CV: 0.4-2.2% and 5.3% for insecticides and atrazine, respectively. The presented MAE-GC-ECD procedure enables extraction and determination of aldrin, dieldrin, endrin and atrazine in soil samples with high recoveries, precision and limits of detections in range 6 ng/g - 8 ng/g in the case of insecticides and 1.5 ng/g for atrazine. The MAE-GC-ECD procedure was applied for the above mentioned pesticides determination in environmental samples. Soils were collected in agricultural as well as rural areas in Poland. In all cases atrazine was determined in concentration range: 0.0187 mg/g - 0.1107 mg/g. Aldrin and dieldrin was detected in soil samples from two locations. RÓWNOCZESNE OZNACZANIE WYBRANYCH INSEKTYCYDÓW I ATRAZYNY W GLEBIE TECHNIKĄ MAE-GC-ECD. Opracowano procedurę MAE-GC-ECD umożliwiającą równoczesną ekstrakcję i oznaczanie insektycydów: aldryny, dieldryny i endryny oraz herbicydu: atrazyny z gleb. Zastosowana metoda GC-ECD charakteryzuje się granicą wykrywalności w zakresie 12-18 μg/ml dla insektycydów oraz 2 μg/m for dla atrazyny. W celu opracowania procedury analitycznej o wysokim odzysku analitów i granicy oznaczalności typowej dla analizy śladowej (100 ppm lub 100 mg/g wg. IUPAC) przeprowadzono badania z zastosowaniem ekstrakcji rozpuszczalnikowej wspomaganej ultradźwiękami (UAE) oraz mikrofalami (MAE) dla różnych rozpuszczalników. Dokonano porównania precyzji oraz odzysków analitów dla obu technik ekstrakcyjnych. Wydzielanie insektycydów z próbek gleb na drodze ekstrakcji rozpuszczalnikowej wspomaganej ultradźwiękami przeprowadzono z odzyskiem 40-85% (CV: 1,3-5,0%), natomiast atrazyny 15% (CV: 8-18%). Najwyższą precyzją i odzyskiem charakteryzowała się metoda MAE z zastosowaniem mieszaniny n-heksan-aceton. Odzyski mieściły się w tym przypadku w zakresie 70-85% (CV: 0,4-2,2%) dla insektycydów oraz 84% (CV: 5,3%) dla atrazyny. Opisana procedura MAE-GC-ECD umożliwia ekstrakcję i oznaczenie aldryny, dieldryny, endryny oraz atrazyny w próbkach gleb. Charakteryzuje się wysokimi odzyskami, precyzją i granicami wykrywalności mieszczącymi się w granicach 6-8 ng/g, w przypadku insektycydów oraz 1,5 ng/g dla atrazyny. Metodyka MAE-GC-ECD została zastosowana do oznaczanie wymienionych pestycydów w próbkach gleb pobranych z terenów rolniczych oraz przemysłowych. We wszystkich próbkach gleb oznaczono atrazynę, której stężenie mieściło się w granicach od 0,0187 mg/g do 0,1107 mg/g w zależności od pochodzenie próbki. Aldryna i dieldryna została wykryta w dwóch próbkach na poziomie poniżej granicy oznaczalności.

Procedures for analysis of atrazine and simazine in environmental matrices.

There is an ongoing need to monitor soil and trophic chain samples for residues of triazine herbicides, particularly atrazine and simazine, because these herbicides are among the most used members of their class, are toxic, can be persistent, and are widely distributed in the environment. The main purpose of this review is to provide an overview of principle techniques and approaches used in analyzing atrazine, simazine, and other triazine herbicide residues in environmental matrices. The methods covered generally provide low detection limits, acceptable levels of matrix interferences, and are relatively fast and inexpensive. Atrazine and simazine are popular herbicides used to control a variety of broad leaf and grassy weeds in agriculture and on industrial sites. Because they are widely and frequently used, the environmental contamination of these compounds is considerable. Atrazine, simazine, and other triazines have the ability to translocate in ecosystems. When this occurs, it is often necessary to monitor their residue content in soils, vegetation, biota, and water. There is a vast literature available that addresses the extraction and clean-up of soil, vegetation, animal tissue, and animal fluid samples; unfortunately, few of these publications compare the effectiveness of results obtained on similar matrices. In this review we endeavor to review and provide comparative information on methods dedicated to determining residues of atrazine, simazine, and other triazines in several environment matrices: soil, plants, animal tissues, and water.

Analysis of herbicides: demonstration of the utility of enzyme immunoassay verification by HPLC

Abstract Evidence has accumulated that herbicides in the environment present a significant health hazard to the population. Therefore, the levels of heavily used substances such as atrazine and simazine and their metabolites need to be regularly assessed. The objective was to develop a rapid and simple tube ELISA procedure suitable for use in field studies and non-specialized laboratories. The antisera used were polyclonal antibodies raised in sheep against atrazine or simazine amido caproic acid conjugated to bovine serum albumin. The antibodies were first used to construct a two-step competitive ELISA procedure in 96-well microtitre plates. The 96-well format was then adapted to a coated-tube enzyme immunoassay, by immobilization of hapten-gelatine conjugates on polystyrene tubes. This enabled the colour to be read using a basic spectrophotometer. Soil samples were collected from agricultural and non-agricultural sites in Poland. Atrazine and simazine were extracted by liquid extraction from soil and assayed by tube ELISA. In addition, the samples were extracted by solid-phase extraction before analysis by HPLC. The immunoassays and chemical analysis were carried out by different individuals who were unaware of each others results, which were then compared at the end of the study. Correlation of the two methods was excellent, with R=98.7 and 81.3 for atrazine and simazine, respectively. The immunoassay yielded the same order of results without having to perform solid-phase extraction before analysis. The study has demonstrated that the simple antigen-coated tube assay provides a cost-effective and valuable screening test. Comparison with the more elaborate, heavily labour-intensive HPLC analysis demonstrated that the results obtained by the simpler enzyme-immunoassay tests were within the same order.

Chemometric Characterization of the Liphophilicity Parameters of Triketone Herbicides and Their Degradation Products

The aim of this work was to determine the correlations between retention factors of selected triketone herbicides (mesotrione MES, sulcotrione SUL, and tembotrione TEMB), their derivatives (AMBA, MNBA, CMBA, CHD, and TEMB MET), and their physicochemical properties as well as chemical structures. Moreover, the comparison of chromatographic lipophilicity scales by means of principal component analysis (PCA) and hierarchical cluster analysis (HCA) was conducted. All experiments were conducted using thin-layer chromatography (TLC). Acetonitrile and 0.1% formic acid in water, as well as the mixtures of the above-mentioned solvents in the ratios 30:70, 50:50, and 70:30 (v/v) were used as mobile phases. Silica gel modified with alkyl chains of different lengths (C-2, C-8, C-18) as well as hydroxyl (OH) and amine (NH2) groups were employed as stationary phases. HCA and PCA were employed to investigate the influence of chemical properties and structures of triketones and their derivatives on chromatographic separations. The chemometric analysis applied in this study enables classification of the chemical and structural properties of the investigated compounds using solely information from thin-layer chromatography.

Determination of Mesotrione, Simazine and Atrazine by RP- HPLC in Thermal Water, Sediment and Vegetable Samples

Abstract This paper presents a simple, relatively inexpensive method for the detection of a group of commonly used herbicides such as mesotrione, simazine and atrazine in vegetables, thermal water and sediment samples by means of reversed phase-high performance liquid chromatography (RP-HPLC) with ultraviolet detection (DAD). The calibration curves were linear in the concentration range of 0.10-5.00 μg/mL. The limits of detection calculated at a signal-to-noise ratio of 3 were in the range of 0.03-0.10 μg/mL. The uncertainties of analytical methods were lower than 10 %. The method was validated by spiking recovery test of mesotrione, simazine and atrazine from the samples. Simazine and atrazine in the concentration range of 0.03-0.82 μg/g were detected in most of the vegetable samples, whereas mesotrione in the concentration of 2.40 and 4.96 μg/ mL was found only in thermal waters and 0.28 μg/g in a sediment sample.

Degradation Processes of Pesticides Used in Potato Cultivations.

Potato is one of the most important crops, after maize, rice and wheat. Its global production is about 300 million tons per year and is constantly increasing. It grows in temperate climate and is used as a source of starch, food, and in breeding industry.Potato cultivation requires application of numerous agro-technical products, including pesticides, since it can be affected by insects, weeds, fungi, and viruses. In the European Union the most frequently used pesticides in potato cultivations check are: thiamethoxam, lambda-cyhalothrin and deltamethrin (insecticides), rimsulfuron (herbicide) and metalaxyl (fungicide).Application of pesticides improves crop efficiency, however, as pesticides are not totally selective, it affects also non-target organisms. Moreover, the agrochemicals may accumulate in crops and, as a consequence, negatively influence the quality of food products and consumer health. Additional risks of plant protection products are related to their derivatives, that are created both in the environment (soil, water) and in plant organisms, since many of these compounds may exhibit toxic effects.This article is devoted to the degradation processes of pesticides used in potato crop protection. Attention is also paid to the toxicity of both parent compounds and their degradation products for living organisms, including humans. Information about the level of pesticide contamination in the environment (water, soil) and accumulation level in edible plants complement the current knowledge about the risks associated with widespread use of thiamethoxam, lambda-cyhalothrin and deltamethrin, rimsulfuron and metalaxyl in potato cultivation.

Quality Control of Plant-Based Foods in Terms of Nutritional Values: Influence of Pesticides Residue and Endogenous Compounds

Abstract Agrochemicals not only increase the efficiency of crop but also accumulate in plant tissues. Moreover, according to the latest reports, pesticides disrupt the natural biochemical processes in plant tissue. In the context of food quality, control monitoring of the metabolism of pesticides in plant organisms becomes particularly essential. Therefore special attention should be paid to the determination not only of pesticides residue but also endogenous compounds (e.g., vitamins, biogenic amines), since their biosynthesis may be interfered by agrochemicals. In this chapter, the quality control problems related to pesticides residue and selected endogenous compounds in food of plant origin will be discussed. Particular emphasis will be placed on the interactions between the previously mentioned compounds leading to changes of nutrient parameters of food. Analytical problems with the determination of agrochemicals, their metabolites, vitamins, and catecholamines and indoloamin will be discussed. The work will be a compendium of information on the interactions between pesticides and certain endogenous compounds in plants. Concurrently it will include a critical discussion of analytical issues related to food control on the contents of the previously mentioned compounds.