Determination Of Herbicide Residues Research Articles

A Facile Determination of Herbicide Residues and Its Application in On-Site Analysis.

Abuse of herbicides in food safety is a vital concern that has an influence on the sustainable development of the world. This work presents, a modified ionization method with separation of the sample and carrier gas inlets, which was utilized for efficient ionization and analyte transfer of herbicides in crops. The working parameters of voltage, injective distance, desorption temperature, and the carrier gas flow rate were optimized to achieve the high efficiency of the transfer and ionization of the analyte. When it was applied in the analysis of herbicides in laboratory, the method exhibited excellent performance in achieving the quantitative detection of herbicides in solutions and residues spiked in an actual matrix with a limit of quantification of 1-20 μg/kg and relative standard deviations of less than 15%. Although a simple QuEchERS process was used, the programmable heating platform ensured efficient gasification and transfer of the target analyte, with the advantages of high speed and selectivity, avoiding the noted matrix effect. The method exhibited a relatively acceptable performance by using air as the discharged gas (open air). It could be used to monitor herbicide residues in the growth stage via on-site non-destructive analysis, which obtained low LODs by dissociating the herbicides from the crops without any pretreatment. It showed great potential for the supervision of the food safety market by achieving non-destructive detection of crops anytime and anywhere. This finding may provide new insights into the determination of pesticide emergence and rice quality assessment.

A new sample treatment strategy based on supramolecular solvent for determination of herbicide residues in water samples by Box-Behnken design

This paper describes a sensitive, simple and green analytical method for pretreatment of sulfonylurea and pyrethroid herbicides in water samples by supramolecular solvent-based liquid phase microextraction (SUPRAS-LPME). The SUPRAS was rapidly formed by nonanoic acid and tetrahydrofuran (THF)/water solution. The attractive features of SUPRAS-LPME include the simplicity, high enrichment factor, low cost and less consumption of organic solvents. The main influencing factors including type and volume of fatty acids, volume of THF, ionic strength, vortex time and volume of formic acid were optimized in detail, and then the significant variables were optimized by Box-Behnken design (BBD). Under the optimized condition, the proposed method shows high precision (RSDs < 13.7 %), low limits of detection (0.5–10 μg L-1) and limits of quantitation (10–45 μg L-1), acceptable recovery (71.3 %-95.9 %). The proposed method was successfully applied for analysis of sulfonylurea and pyrethroid herbicides in water samples, making it an alternative analytical strategy for determination of trace analytes at the microgram per liter range with desirable sensitivity.

Comparison of Ultrasonic and QuEChERS Extraction Methods Efficiency for the Determination of Herbicides Residues in Soil and Maize Cob

In this study, the optimization and application of ultrasonic extraction and QuEChERS methods was conducted for the effective extraction of pesticides from maize and their corresponding soil samples. The characterization pesticides (Atrazine, glyphosate, 2,4-dichlorophenoxyacetic acid and mesotrione) was done with gas chromatography-flame ionization detector. Factors influencing the efficiency of the extraction methods such as the extraction solvent, extraction time, solvent volume and spiking concentration were assessed. Under the optimum experimental conditions, the recoveries of analytes ranged between 100 - 104 % in maize cop and 91 - 97 % in soil for ultrasonic method, while they were 94 - 115 % in maize cob and 89 - 101 % in soil for QuEChERS method. The repeatability, articulated as RSD values were less than 5 % for all analytes in both methods. The limits of detection and limit of quantification ranged from 0.02 - 0.15 µg L−1 and 0.2 - 0.5 µg L−1 for ultrasonic method and 0.01 - 0.23 µg L−1 and 0.13 - 0.8 µg L−1 for QuEChERS method. The lower limits of detection and quantification with higher recoveries suggests that both methods can be accurately applied for the determination of the assessed pesticides in soil and maize cop. Herbicides concentrations ranged between 0.33 - 45.10 µg L−1 in soil and 6.15 - 34.2 µg L−1 in maize cob. In all studied herbicides, maize residues detected were found to be higher compared to maize allowable maximum residue limits however, atrazine in all soil samples was found to be lower compared to soil allowable maximum residue limits. This indicates the importance of continuous monitoring the herbicides residues in maize to safeguard health for the consumers. HIGHLIGHTS Crops compete with lots of undesired plants that naturally grow and compete for carbon dioxide, space, nutrients, sunshine and water Agricultural sector plays a significant role in food security, production and steady supply by employing herbicides and agrochemicals to achieve high crop yield in a short space of time Crop and soil health are evaluated for herbicides toxicity as herbicides contains toxic chemicals that poses a risk to the consumer and the environment GRAPHICAL ABSTRACT

Гербіциди з групи нітродифенілових етерів: застосування в Україні, методи контролю, методика визначення залишків оксифлуорфену в зерні та олії сої

A review of analytical methods for the determination of herbicide residues from the group of nitrodiphenyl ethers in the environment and agricultural products, developed and validated a method for oxyfluorfen determination in soybean grain and oil method GC/ECD, which meets regulatory requirements and solves the problem of toxicant control in the above matrices. The developed method uses modern methods of sample preparation, identification and quantification of oxyfluorfen (selective extraction, capillary gas-liquid chromatography (GC/ECD GC/MS). The method is validated according to EU requirements) (SANTE/12682/2019 quality control and analytical validation procedures for pesticide residues analysis in food and feed). Key words: gas-liquid chromatography, mass spectrometry, herbicides, nitrodiphenyl ethers, control, residual amounts.

Dynamics of the Degradation of Acetyl-CoA Carboxylase Herbicides in Vegetables.

(1) Background: Aryloxyphenoxy-propionates and cyclohexanediones are herbicides most widely used in dicot crops worldwide. The main objective of the study was to determine the dynamics of herbicide residues in carrot, lettuce, cauliflower, and onion in order to suggest a low level of residues in harvested vegetables. (2) Methods: Small plot field trials were carried out in four vegetables in the Czech Republic. The samples of vegetables were collected continuously during the growing season. Multiresidue methods for the determination of herbicide residues by LC-MS/MS were used. Non-linear models of degradation of individual herbicides in vegetables were calculated using the exponential decay formula. Action GAP pre-harvest intervals for the 25% and 50% maximum residue limit (MRL) and 10 µg kg−1 limit (baby food) were established for all tested herbicides. (3) Results: The degradation dynamics of fluazifop in carrot, onion, and cauliflower was significantly slower compared to quizalofop and haloxyfop. The highest amount (2796 µg kg−1) of fluazifop residues was detected in cauliflower 11 days after application. No residue of propaquizafop and cycloxydim was detected in any vegetable samples. (4) Conclusions: Aryloxyphenoxy-propionate herbicide (except propaquizafop) could contaminate vegetables easily, especially vegetables with a short growing season. Vegetables treated with fluazifop are not suitable for baby food. Lettuce and cauliflower treated by quizalofop are not suitable for baby food, but in onion and carrot, quizalofop could be used. Propaquizafop and cycloxydim are prospective herbicides for non-residual (baby food) vegetable production.

Determination of Herbicide Residues using LC-MS/MS in Direct Seeded Cultivated Paddy under Drip Irrigation System

Determination of Herbicide Residues using LC-MS/MS in Direct Seeded Cultivated Paddy under Drip Irrigation System

Herbicide Residues in Soil and Varieties of Rice (&amp;lt;i&amp;gt;Oryza sativa&amp;lt;/i&amp;gt; L.) Samples from Borno State, Nigeria

The objectives were to determine the concentrations of herbicide residues in soil and different varieties of rice (Oryza sativa L.) and to compare the levels with allowable limits set by WHO/FAO. Four varieties of rice samples (Narica 1, Marica 2, De-gold and Faro 44 were collected from Zabarmari and Bulamari agricultural locations for the determination of herbicide residues. Extraction and cleanup of the samples were carried out using standard analytical procedures. The levels of the studied herbicide residues were determined using Agilent 7890A GC/MS. From the results of the study, it was observed that paraquat and butachlor are the most dominant used herbicides in the study area due to their higher concentrations in the soil and rice samples. The concentrations of all the studied herbicides were significantly higher in the soil samples as compared to the rice samples. The concentrations of all the herbicides in the soil samples were observed to be higher at depth of 0-10cm, while the lowest concentrations were detected at the depth of 20-30 cm. The study clearly indicates that some of the studied herbicide residues in the rice samples were significantly higher than the WHO and FAO maximum residue limits (MRLs) and acceptable daily intake values (ADIs). Hence, this high values of residues of herbicide call for strict vigilance and constant monitoring in other to protect further contamination of the cultivated rice by herbicides.

Development and Validation of a Liquid Chromatography–Tandem Mass Spectrometry Method for Multiresidue Determination of 25 Herbicides in Soil and Tobacco

In the cultivation of tobacco, crop rotation patterns, such as tobacco/rice or tobacco/corn, are widely used. However, the use of herbicides in the rice or corn phase can lead to their being taken in during the tobacco phase by inner conduction action. In the present study, to monitor the use of herbicides in tobacco, a sensitive and simple analytical method coupled with liquid chromatography-tandem mass spectrometry (LC–MS/MS) has been established for determination of 25 herbicides in soil as well as fresh and flue-cured tobacco leaf. The herbicides analyzed include six aryloxy phenoxy propionate herbicides (APPs) and 19 sulfonylureas herbicides (SUs). The samples were extracted using acetonitrile and purified using C18 sorbent before analysis. Optimum separation of the analytes was achieved using an Agilent Eclipse XDB-C18 column at 40 °C and gradient elution with acetonitrile and 0.1% aqueous formic acid as the mobile phase at a flow rate of 0.8 mL min−1. The limits of quantification and detection are in the ranges 0.08–1.00 mg kg−1 and 0.024–0.30 mg kg−1, respectively, and matrix effects in the range − 70 to 50% were achieved. The recovery rates obtained from spiked soil and tobacco leaf samples ranged from 72.32 to 116.83% with intra-day and inter-day relative standard deviations of 0.44–11.55%. In addition, the method developed was applied to the determination of herbicides residues in actual soil and tobacco samples, revealing that the proposed method can detect trace amounts of APPs and SUs in soil as well as in fresh and flue-cured tobacco leaf.

Ionic Liquid-Assisted Liquid-Liquid Microextraction based on the Solidification of Floating Organic Droplet in Sample Preparation for Simultaneous Determination of Herbicide Residues in Fruits.

An ionic liquid-assisted liquid-liquid microextraction based on the solidification of floating organic droplet (ILSFODLLME) was investigated for analysis of four herbicide residues (i.e. simazine, atrazine, propazine, and linuron) by high performance liquid chromatography. For ILSFOD-LLME, the optimal extraction conditions were 5% w/v Na2SO4, 30 μL [C4MIM][PF6]RTIL, 100 μL of 1-octanol, ultrasonication time 30 s and centrifugation at 5000 rpm for 5 min. Under the optimal conditions, linearity was obtained within the range of 0.1-1000 μg kg-1, with the correlation coefficients greater than 0.999. The high enrichment factors of the target analytes were in the range of 64.5-139.9 and low limit of detection could be obtained. A modified QuEChERS was applied for fruit sample preparation before analysis. Matrix effects were also investigated using matrix matched standards for construction of the calibration graph. The proposed method has been successfully applied for extraction and preconcentration of herbicide residues in fruit samples, and good recoveries in the range of 87.32% to 99.93% were obtained.

Simultaneous determination of herbicide residues in tobacco using ultraperformance convergence chromatography coupled with solid-phase extraction.

A time-saving and organic solvent efficient method to simultaneously determine six kinds of herbicide residues in tobacco using solid-phase extraction for sample clean-up and preconcentration and the highly sensitive ultraperformance convergence chromatography method was developed. Parameters for ultraperformance convergence chromatography, including the choice of stationary phase and modifiers, autobackpressure regulator pressure, column temperature, and the flow rate of mobile solvents, were optimized. The herbicide residues of napropamide, alachlor, quizalofop-ethyl, diphenamid, metolachlor, and clomazone in tobacco samples were successfully separated and detected at levels as low as 0.0043-0.0086 mg/kg within 5 min using a nonpolar high strength silica C18 selectivity for bases column and methanol as the cosolvent of the mobile phase of carbon dioxide (75-99.9%, v/v). Analysis of tobacco samples had recoveries of 69.8-95.0%, limit of quantitation of 0.0127-0.0245 mg/kg, limit of detection of 0.0043-0.0086 mg/kg, and correlation coefficient of >0.9990. Results support this method as an efficient alternative to current methodologies for the determination of herbicide residues in tobacco.

Quantification of triazine herbicides in soil by microwave-assisted extraction and high-performance liquid chromatography

A method for the determination of herbicides residues, triazine (atrazine, metribuzin, ametryn, and terbutryn), in soil samples with high-performance liquid chromatography (HPLC)-UV detection is described. The proposed method is based on microwave-assisted extraction (MAE) of soil samples for 4 min at 80% of 850-W magnetron outputs in the presence of mixture of solvents (methanol/acetonitrile/ethylacetate). Related important factors influencing the MAE efficiency, such as the solvent type and volume, irradiation energy, and time, were optimized in detail. Calibration curve ranges established using HPLC for metribuzin, atrazine, ametryn, and terbutryn are 1.0-19.0, 0.9-18.0, 0.6-11.0, and 0.7-11.0 µg mL( -1), respectively. The limits of detection of metribuzin, atrazine, ametryn, and terbutryn are 0.30, 0.24, 0.16, and 0.20 µg mL( -1) while limits of quantification are 1.0, 0.80, 0.50, and 0.60 µg mL( -1), respectively. A Plackett-Burman factorial design was used as a screening method in order to select the variables that influence MAE extraction. The recoveries of the method at three different spiked levels were assessed by analyzing real soil samples and were found to be in the range of 83.33 ± 0.12-96.33 ± 0.23 with good precision (<8%).

Ultrasonic solvent extraction and nonaqueous CE for the determination of herbicide residues in potatoes

In the present work we address the development of a simple and effective method for the determination of triazine herbicide residues in horticultural products by CE in nonaqueous media (NACE). Potato samples were selected as a representative matrix of such foods with a nonfatty content. Isolation of the analytes from the sample matrix was accomplished by extraction with organic solvents, assisted by ultrasound; a clean-up step of the organic extracts was carried out with SPE, using an Oasis MCX(R) sorbent to retain the analytes directly from the organic medium. The detection limits achieved in spiked potatoes (1.7-4.0 mug/kg) were lower than the default value of maximum residue level (MRL) established by current EU legislation for pesticide residues in foodstuffs. The results obtained were compared with HPLC in order to evaluate the performance of the NACE procedure.

Identification and determination of herbicide residues in wheat by HPLC

Identification and determination of herbicide residues in wheat by HPLC

Microwave pretreatment and gas chromatography–mass spectrometry determination of herbicide residues in onion

A rapid multi-residue method was developed for the determination of 16 herbicides in onion. The analytical procedure was based on preventing formation of sulfur-containing compounds in onion by microwave inactivation of the enzyme alliinase. The onion samples which had been pretreated were extracted with acetonitrile and cleaned by solid-phase extraction. The herbicide residues in onion were detected by gas chromatography/mass spectrometry with selected ion monitoring. The recoveries of 16 herbicides ranged from 69.2% to 105.0% with the relative standard deviations (RSD) below 10.7%. The limit of quantitation (LOQ) ranged from 0.003 to 0.015 mg kg −1. The method was applied to the analysis of herbicide residues in onion samples.

Determination of Herbicide Residues in Garlic by GC–MS

A rapid multi-residue method has been developed for the determination of 16 herbicides in garlic. The analytical procedure is based on prior microwave heating prevention of the generation of sulfur-containing compounds. The garlic samples which had been pretreated were extracted with acetonitrile and cleaned up by solid-phase extraction. The herbicide residues were detected by gas chromatography–mass spectrometry with selected ion monitoring. The recoveries of 16 herbicides ranged from 69.0 to 105.4% with the relative standard deviations (RSD) below 10.1%. The limit of quantification (LOQ) ranged from 0.003 to 0.015 mg kg−1.

Determination of herbicide residues in olive oil by gas chromatography–tandem mass spectrometry

This paper reports a method for the analysis in olive oil of multiresidues of the herbicides of low-medium polarity most widely used by Andalusian olive growers. The method, which uses gas chromatography/tandem mass spectrometry (GC–MS/MS), was developed within the framework of Project CAO00-005, which spanned the period from 2000 to 2004. The results obtained for more than 3000 samples of virgin olive oil and organic olive oil analyzed over such a period are reported. Samples were extracted with an acetonitrile/ n-hexane mixture and cleaned up by passage through Florisil columns prior to analysis. A linear determination range for the herbicides from 1 to 500 μg kg −1 and a correlation coefficient better than 0.996 were achieved. The reproducibility, as relative standard deviation, was quite acceptable (8–11%), and so were herbicide recoveries (90–102%). The proposed method has been transferred to both public and private laboratories in the Andalusian region.

Effect of temperature on the disappearance of four triazine herbicides in environmental waters

The influence of temperature on the disappearance of four s-triazine herbicides, terbuthylazine, simazine, atrazine and prometryn was studied in sea, river and groundwaters spiked with approx. 5 mg l −1 of each during long-term laboratory incubation. Residues were analyzed by GC-NPD and confirmed by GC-MSD. No clean-up was necessary and a micro on-line method for the determination of herbicide residues was used. The results showed that temperature had little effect on the behaviour of the four herbicides in river and seawaters but strongly affected their behaviour in groundwater. Simazine was the most readily affected compound in sea, river and groundwaters, while terbuthylazine and atrazine were the most persistent in all cases, especially in riverwater. Half-lives ranged from 41 days (constant rate=0.017 days −1) to 196 days (constant rate=0.003 days −1) for simazine (40 °C) and terbuthylazine (20 °C), respectively, in riverwater. Only for terbuthylazine in riverwater was the remaining percentage at the end of the experiment higher than 50% (58%, 3.21 mg l −1). In the other cases, the remaining percentage varied from 4% (0.20 mg l −1, 40 °C) to 43% (2.25 mg l −1, 20 °C) for simazine and terbuthylazine, respectively, in groundwater.

Chromatographic determination of herbicide residues in various matrices.

The newest results in the use of various extraction techniques and chromatographic methods such as gas-liquid and high-performance liquid chromatography used for the assessment of herbicide residues in various matrices have been compiled and critically evaluated. Practical employments in water and soil research, environmental protection, clinical and food chemistry are presented.

Determination of herbicide residues in juice by matrix solid-phase dispersion and gas chromatography–mass spectrometry

A rapid multiresidue method was developed for the determination of 15 herbicides in carrot, grape, and multivegetable juices. The analytical procedure was based on the matrix solid-phase dispersion of juice samples on Florisil, placed in glass columns, and subsequent extraction with ethyl acetate with assisted sonication. The recoveries through the method ranged from 82 to 115% with relative standard deviations equal or lower than 10% for all the herbicides studied. The analysis of samples was accomplished using gas chromatography–mass spectrometry with selected ion monitoring. Spiked blank samples were used as standards to counteract the matrix effect observed in the chromatographic determination. The detection limits ranged from 0.1 to 1.6 μg/l. The developed method was applied to the analysis of herbicide residues in commercial juice samples.

Determination of herbicide residues by laser microprobe mass analysis (Lamma)

Diffusion of herbicide residues and derived substances in ecosystems can arise from agrochemical treatments, depending on environmental interactions and the chemical characteristics of the parent molecules and their degradation products. As adsorption phenomena affect both herbicide residues and their metabolites, a complete extraction and identification of them is very difficult with traditional methods. Laser ablation could be an effective system of analysis of herbicides on solid surfaces (soil, leaves) especially in the presence of degraded residues and several by-products. Acifluorfen, a diphenylether herbicide, and rimsulfuron, a sulfonylurea herbicide, were irradiated with a Nd:YAG laser at 266 nm. The decomposition fragments were detected by using a time-of-flight mass spectrometer. This technique allows the identification of stable ions useful for a better determination of the analytes. Fragments derived from a decarboxylation reaction and cleavage of the ether function of acifluorfen were obtained. In the case of rimsulfuron, fragments deriving from the pyrimidine ring, such as 2-amino-4,6-dimethoxypyrimidine, were detected.