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1.
Artículo en Inglés | MEDLINE | ID: mdl-39285113

RESUMEN

Biomonitoring of persistent pesticides in birds of prey has been carried out for decades, but few studies have investigated their relevance for the monitoring of non-persistent pesticides. Herein, we determined the contamination patterns of multiple pesticides in Montagu's harrier (Circus pygargus) chicks in an intensive farming area of southwestern France. Blood samples from 55 chicks belonging to 22 nests in 2021 were assessed for 104 compounds (herbicides, fungicides, insecticides, safeners and synergists). All chicks had at least one herbicide in their blood, and half had at least two compounds. The 28 compounds detected comprised 10 herbicides, 12 fungicides, 5 insecticides and 1 synergist. Mixtures in blood were predominantly composed of herbicides, and six chicks presented a mixture of the three pesticide classes. The most prevalent compounds were sulcotrione (96% of chicks), tebutam (44%) and chloridazon (31%), of which the latter two had been banned in France for 19 and 3 years, respectively, at the time of sampling. Most compounds are considered non-acutely toxic, but sulcotrione is potentially carcinogenic, mutagenic and reprotoxic, raising questions about the effects on the health of nestlings. Biomonitoring of multiple pesticides through Montagu's harrier chicks in agroecosystems is clearly relevant because it reflects the general pattern of agricultural pesticide use in the study area. It also raises questions about exposure pathways in chicks, and further investigations are needed to disentangle the roles of dietary routes and maternal transfer for the established pesticide contamination patterns.

2.
Anal Chim Acta ; 1307: 342624, 2024 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-38719414

RESUMEN

BACKGROUND: Pesticides are used in agricultural production for prevent and control crop diseases and pests, but it is easy to cause excessive pesticides residues in agricultural products, polluting the environment and endangering human health. Due to their unmatched and sustainable capabilities, nanoextraction procedures are becoming every day more important in Analytical Chemistry. In particular, nanoconfined liquid phase extraction has shown extraction capabilities toward polar, medium polar, and/or nonpolar substances, which can be easily modulated depending on the nanoconfined solvent used. Furthermore, this "green" technique showed excellent characteristics in terms of recoveries, extraction time (≤1 min), reliability, and versatility. (97) RESULTS: In this work, the advantages of this technique have been coupled with those of filtration membrane extraction, making use of carbon nanofibers (CnFs) growth on carbon microspheres (CµS). This substrate has been deposited on a filter, which combined with gas chromatographic mass spectrometry (GC-MS) analysis successfully employed for the nanoextraction of 30 pesticides (18 organochlorine and 12 pyrethroids) in tea samples. Under the optimized extraction conditions, the linear range with standard solutions was from 1 to 1000 ng mL-1 (R2 ≥ 0.99), the limit of detections in tea samples were in the range 0.56-17.98 µg kg-1. The accuracy of the developed method was evaluated by measuring the extraction recovery of the spiked tea samples, and recoveries between 74.41 % and 115.46 %. (119) SIGNIFICANCE: Considering the versatility of nanoconfined liquid phase extraction and the functionality of the filtration membrane extraction procedure, this new extraction method can be considered a powerful candidate for automatized high-throughput analyses of real samples. (34).


Asunto(s)
Filtración , Hidrocarburos Clorados , Extracción Líquido-Líquido , Plaguicidas , Piretrinas , , Té/química , Piretrinas/análisis , Piretrinas/aislamiento & purificación , Hidrocarburos Clorados/análisis , Hidrocarburos Clorados/aislamiento & purificación , Extracción Líquido-Líquido/métodos , Filtración/métodos , Plaguicidas/análisis , Plaguicidas/aislamiento & purificación , Cromatografía de Gases y Espectrometría de Masas/métodos , Membranas Artificiales
3.
Toxics ; 11(11)2023 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-37999535

RESUMEN

The escalating utilization of pesticides has led to pronounced environmental contamination, posing a significant threat to agroecosystems. The extensive and persistent global application of these chemicals has been linked to a spectrum of acute and chronic human health concerns. This review paper focuses on the concentrations of airborne pesticides in both indoor and outdoor environments. The collection of diverse pesticide compounds from the atmosphere is examined, with a particular emphasis on active and passive air sampling techniques. Furthermore, a critical evaluation is conducted on the methodologies employed for the extraction and subsequent quantification of airborne pesticides. This analysis takes into consideration the complexities involved in ensuring accurate measurements, highlighting the advancements and limitations of current practices. By synthesizing these aspects, this review aims to foster a more comprehensive and informed comprehension of the intricate dynamics related to the presence and measurement of airborne pesticides. This, in turn, is poised to significantly contribute to the refinement of environmental monitoring strategies and the augmentation of precise risk assessments.

4.
Molecules ; 28(18)2023 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-37764387

RESUMEN

The vast quantity and high variety of pesticides globally used in agriculture entails considerable risks for the environment and requires ensuring the safety of food products. Therefore, powerful analytical tools are needed to acquire qualitative and quantitative data for monitoring pesticide residues. The development of ambient ionization mass spectrometry methods in the past two decades has demonstrated numerous ways to generate ions under atmospheric conditions and simultaneously to reduce the need for extended sample preparation and circumvent chromatographic separation prior to mass analysis. Swab spray ionization enables the generation of ions directly from swabs via the application of high voltage and solvent flow. In this study, swab sampling of fruit surfaces and subsequent ionization directly from the swab in a modified electrospray ion source was employed for the screening and quantitation of pesticide residues. Aspects regarding sample collection, sampling efficacy on different surfaces, and swab background are discussed. The effect of solvent composition on pesticide-sodium adduct formation and the suppression of ionization by the background matrix have been investigated. Furthermore, a novel approach for the quantitation of pesticide residues based on depletion curve areas is presented. It is demonstrated that swab spray ionization is an effective and quick method for spectral library-based identification and the quantitative analysis of polar contact pesticide residues on food.


Asunto(s)
Residuos de Plaguicidas , Plaguicidas , Residuos de Plaguicidas/análisis , Frutas/química , Espectrometría de Masas , Plaguicidas/análisis , Solventes/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos
5.
Foods ; 12(16)2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37628000

RESUMEN

The development of efficient methods for evaluating pesticide residues is essential in order to ensure the safety and quality of agricultural products since the Republic of Korea implemented the Positive List System (PLS). The objective of this research was to establish a method for the simultaneous analysis of 322 pesticide residues in fruits and vegetables (such as coffee, potato, corn, and chili pepper), using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach in combination with gas chromatography-tandem mass spectrometry (GC-MS/MS). This study introduces a robust, high-throughput GC-MS/MS method for screening the target pesticide residues in agricultural products, achieving the PLS criterion of 0.01 mg/kg LOQ. Despite some compounds not aligning with the CODEX recovery guideline, sufficient reproducibility was confirmed, attesting to the method's applicability in qualitative analyses. A health risk assessment conducted using estimated daily intake/acceptable daily intake ratios indicated low risks associated with product consumption (<0.035391%), thereby confirming their safety. This efficient method holds significant implications for the safe distribution of agricultural products, including during import inspections.

6.
Adv Exp Med Biol ; 1425: 507-512, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37581825

RESUMEN

Tirupati is one of the famous tourist places in India. So, safe drinking water is a priority. Therefore, to handle ground water contamination and to make aware the people in the area of Tirupati, in the present paper, research was conducted with the goal to estimate water quality by using physico-chemical parameters and to analyse pesticides with analytical technique Gas Chromatography-Mass Spectrometry (GC-MS) of ground water in and around Tirumala, Tirupati, located in Andhra Pradesh State of India. For this estimation, ground water samples were collected from different locations of Tirupati, i.e. Sri Padmavati Mahila Visvavidyalayam (SPMVV) (Women's University), Mallamgunta, LalBahudhur (LB) Nagar, Singalagunta, Sri Venkateshwara (SV) University, Perumallapalli, Settipalli, Akkarampalli (AK Palli), Srikrishna Nagar, Gandhipuram, Pathalaganga and Cherlopalli areas, and water quality parameters (alkalinity, pH, total hardness, chloride, calcium, potassium and silica) were tested. Based on the physico-chemical parameters obtained it can be concluded that the water was good. Tirumala Pathalaganga water was found be within the standard limits set by the World Health Organisation (WHO), so it is pure water without any contaminants. Reverse Osmosis (RO) water does not contain any contaminants; it is free from dissolved solids and ions so it is pure and clean water. Ground water sample that was collected from Tirupati area was less polluted than surface water sample, so it is pure when compared with tap water. Hence, drinking water pollution should be controlled by the proper environment management plan. Ground and surface water of this area should be treated to make it suitable for drinking and to maintain proper health conditions of people living in this area. All samples that were collected from groundwater from the fields of Settipalli area exceeded the standard limits set by the WHO and Bureau of Indian Standards (BIS), which suggests poor water quality. The present study reported the contamination status of diclorvos, methyl parathion, parathion and malathion in ground water of Tirupati in Settipalli, Andhra Pradesh, India. In agriculture, pesticides are frequently viewed as a quick, simple and low-cost option for controlling weeds and insect pests. The results obtained from the present study shall be useful in future management of the ground water in Tirupati area.


Asunto(s)
Plaguicidas , Contaminantes Químicos del Agua , Femenino , Humanos , Calidad del Agua , Abastecimiento de Agua , Monitoreo del Ambiente
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 301: 122954, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37270975

RESUMEN

Pesticide active ingredients (AIs) are often applied with adjuvants to facilitate the stability and functionality of AIs in agricultural practice. The objective of this study is to investigate the role of a common non-ionic surfactant, alkylphenol ethoxylate (APEO), on the surface-enhanced Raman spectroscopic (SERS) analysis of pesticides as well as its impact on pesticide persistence on apple surfaces, as a model fresh produce surface. The wetted areas of two AIs (thiabendazole and phosmet) mixed with APEO were determined respectively to correct the unit concentration applied on apple surfaces for a fair comparison. SERS with gold nanoparticle (AuNP) mirror substrates was applied to measure the signal intensity of AIs with and without APEO on apple surfaces after a short-term (45 min) and a long-term (5 days) exposure. The limit of detection (LOD) of thiabendazole and phosmet using this SERS-based method were 0.861 ppm and 2.883 ppm, respectively. The result showed that APEO decreased the SERS signal for non-systemic phosmet, while increased SERS intensity of systemic thiabendazole on apple surfaces after 45 min pesticide exposure. After 5 days, the SERS intensity of thiabendazole with APEO was higher than thiabendazole alone, and there was no significant difference between phosmet with and without APEO. Possible mechanisms were discussed. Furthermore, a 1% sodium bicarbonate (NaHCO3) washing method was applied to test the impact of APEO on the persistence of the residues on apple surfaces after short-term and long-term exposures. The results indicated that APEO significantly enhanced the persistence of thiabendazole on plant surfaces after a 5-day exposure, while there was no significant impact on phosmet. The information obtained facilitates a better understanding of the impact of the non-ionic surfactant on SERS analysis of pesticide behavior on and in plants and helps further develop the SERS method for studying complex pesticide formulations in plant systems.


Asunto(s)
Malus , Nanopartículas del Metal , Plaguicidas , Fosmet , Plaguicidas/análisis , Malus/química , Fosmet/análisis , Tensoactivos , Oro/química , Tiabendazol/análisis , Nanopartículas del Metal/química , Lipoproteínas
8.
J Chromatogr A ; 1694: 463906, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-36907077

RESUMEN

Clean-up step is essential during the multiresidue sample preparation process to remove undesired matrix components that may cause analytical interferences or suppression effect. However, its application generally by specific sorbents entails time-consuming work producing low recoveries for some compounds. Moreover, it usually needs to be adapted to the different co-extractives from the matrix present in the samples by using different chemical sorbents increasing the number of validation procedures. Therefore, the development of a more efficient and automated and unified clean-up procedure means a significant time reduction and laboratory work with improved performance. In this study, extracts from different matrices (tomato, orange, rice, avocado and black tea) were purified by manual dispersive clean-up (different procedures according to the matrix group) in parallel with an automated µSPE clean-up workflow, in both cases based on QuEChERS extraction. The latter procedure employed clean-up cartridges containing a mixture of sorbent materials (anhydrous MgSO4/PSA/C18/CarbonX) suitable for multiple matrices. All the samples were analysed by liquid chromatography mass spectrometry and the results obtained from both procedures have been compared in terms of the extract cleanness, performance, interferences, and sample workflow. At the levels studied, similar recoveries were achieved by both techniques (manual and automated) except for reactive compounds when PSA was used as the sorbent material producing low recoveries. However, the µSPE recoveries were between 70-120%. Furthermore, closer calibration line slopes were provided when µSPE was applied to the different matrix groups studied. It is important to note that up to 30% more samples per day can be analysed using an automated µSPE compared to the manual method (which requires shaking, centrifuging, then taking the supernatant and adding formic acid in ACN); it also provides good repeatability - an RSD (%) < 10%. Consequently, this technique is a very useful option for routine analyses, greatly simplifying the work of muti-residue methods.


Asunto(s)
Residuos de Plaguicidas , Plaguicidas , Humanos , Masculino , Plaguicidas/análisis , Residuos de Plaguicidas/análisis , Espectrometría de Masas en Tándem/métodos , Antígeno Prostático Específico/análisis , Cromatografía Liquida/métodos , Extracción en Fase Sólida/métodos
9.
Foods ; 12(6)2023 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-36981154

RESUMEN

With the popularity of multi-residue pesticide analysis based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) cleanup and liquid chromatography-mass spectrometry (LC-MS), matching optimal matrix-matched calibration protocols and LC-MS conditions to reduce matrix effects (MEs) has become a crucial task for analysts in their routines. However, dozens to hundreds of pesticide analytes in a single run generate increasingly multi-dimensional ME data, requiring appropriate tools to handle these data sets. Therefore, we established an ME analysis strategy by drawing on analytical thinking and tools from metabolomics analysis. Using this, matrix species-induced and mass spectrometry-induced systematic ME variations were distinguished, and pesticides contributed to the variations were scanned out. A simultaneous weakening of MEs on 24 pesticides in 32 different matrices was achieved using the time-of-flight-mass spectrometry (TOF-MS) scan under the information-dependent acquisition (IDA) mode of high-resolution mass spectrometry (HR-MS), compared to multiple reaction monitoring (MRM) scanning by tandem mass spectrometry (MS/MS). Bay leaf, ginger, rosemary, Amomum tsao-ko, Sichuan pepper, cilantro, Houttuynia cordata, and garlic sprout showed enhanced signal suppression in the MRM scan for 105 differential MRM transitions for 42 pesticides and in IDA mode for 33 pesticides, respectively. This study revealed the interference of matrix species and mass spectrometry on MEs and provided a novel strategy for ME analysis.

10.
J Environ Sci Health B ; 58(2): 158-194, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36840342

RESUMEN

The paper reports a multiresidue method that was validated on 220 multi-class pesticides in three major Indian soils, namely, (i) new alluvial soil (NAS); (ii) red lateritic soil (RS) and (iii) black soil (BS) from three different regions. An ethyl acetate-based extraction method with a freezing-out cleanup step was employed for sample preparation, followed by gas chromatography-tandem mass spectrometric analysis. The method that was initially optimized on BS worked satisfactorily for the other two soil matrices. At the spiking level of 10 µg/kg (LOQ), the recoveries were satisfactory (within 70-120%) with precision-RSDs, ≤20% (n = 6) for 85, 88.6, and 89% of compounds in BS, RS, and NAS respectively. At 20 µg/kg, the method performance was satisfactory in each soil for all pesticides. When this validated method was applied to analyse 25 field samples, 6 pesticides were detected in them. In each case, precision (RSD) was <20%. The method sensitivity, accuracy and precision complied with the SANTE/2020/12830 guidelines. The method can be applied for environmental monitoring and risk assessment purposes, thus aiding in regulating pesticide usage in agricultural fields. The limitations and future scope of the study are also discussed.HighlightsA multiresidue method is reported for simultaneous analysis of multi-class pesticides in diverse soilsThe method was validated on 220 pesticides in new alluvial, red lateritic and black soilsSample preparation involved extraction with ethyl acetate and cleanup by a freezing stepThe residues were estimated by gas chromatography tandem mass spectrometry (GC-MS/MS)The method accuracy and precision complied with the EU's SANTE guidelines.


Asunto(s)
Residuos de Plaguicidas , Plaguicidas , Plaguicidas/análisis , Espectrometría de Masas en Tándem/métodos , Residuos de Plaguicidas/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Suelo , Extracción en Fase Sólida/métodos
11.
Sci Total Environ ; 870: 161872, 2023 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-36716873

RESUMEN

This study systematically investigated the occurrence, spatiotemporal distribution, and ecological risk of 106 pesticides in the surface water of the Jiaodong Peninsula in China. The results show that 52 pesticides, including 21 insecticides, 10 fungicides, and 21 herbicides, were detectable in the surface water. The concentrations of target pesticides in water samples ranged from 0.42 (tebuconazole in the wet season) to 645.31 ng/L (thiamethoxam in the normal season). The two most polluting and widespread pesticides were quintozene (maximum concentration of 481.46 ng/L and detection rate of 94 %) and atrazine (maximum concentration of 465.73 ng/L and detection rate of 100 %). The total pesticide concentrations in surface water in different seasons revealed the order of dry season > wet season > normal season. Based on aquatic pesticide concentrations, their frequency of occurrence, and effect concentrations, insecticides posed higher risks to aquatic organisms and human health than either fungicides or herbicides. Total pesticide concentrations were significantly positively correlated with suspended particulate matter, dissolved organic carbon, soil pH, normalized difference vegetation index, adjacent cropland area; and were negatively associated with adjacent grassland area. The cropland area largely influences pesticide distribution in the surface water of the Jiaodong Peninsula.


Asunto(s)
Fungicidas Industriales , Herbicidas , Insecticidas , Residuos de Plaguicidas , Plaguicidas , Contaminantes Químicos del Agua , Humanos , Residuos de Plaguicidas/análisis , Agua , Contaminantes Químicos del Agua/análisis , Plaguicidas/análisis , Agricultura , China , Monitoreo del Ambiente/métodos
12.
J Chromatogr A ; 1662: 462738, 2022 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-34915191

RESUMEN

This paper represents the results of a case study investigating the development of a novel, simple, cost-effective, solventless and sensitive chromatographic method for the determination of volatile pesticides in aqueous samples by an electrothermally prepared pencil graphite (PG). In this study, PG were conditioned by passing a suitable direct current to activate PG by Joule effect. Conditioned PG was used for the extraction of Chlorpyrifos (CP), which is used as case study. The method was also found successful in the determination of CP in real water samples, providing acceptable recovery values (82-111%).


Asunto(s)
Cloropirifos , Grafito , Residuos de Plaguicidas , Plaguicidas , Cloropirifos/análisis , Residuos de Plaguicidas/análisis , Plaguicidas/análisis , Agua/análisis
13.
Environ Pollut ; 289: 117955, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34435567

RESUMEN

Mangroves are unique coastal ecosystems, located in tropical and subtropical regions. Yet, the functioning of these essential ecosystems is threatened by the presence of pollutants, including pesticides originating from agricultural activities. We investigated pesticide residues in the Guayas estuarine environment, since agricultural activities rapidly increased in the Guayas river basin over the past decades. A multi-residue analysis involving a selection of 88 pesticides was performed on the white meat and the hepatopancreas of the red mangrove crab (Ucides Occidentalis) at 15 sampling sites within the Guayas estuary along with water, sediment, and leaves samples. We found that 35 active compounds were present in the Guayas estuary, of which pyrimethanil was most commonly detected and had the highest concentrations in almost all compartments. Also, cadusafos was present in all studied compartments of the Guayas mangrove system and several prohibited pesticides (including carbendazim, carbofuran, and parathion) were detected. An ecotoxicological and probabilistic consumer risk assessment pointed out that current butachlor, carbendazim, and fludioxonil concentrations can cause adverse effects in aquatic organisms in the long term. Moreover, high potential acute and chronic risks of cadusafos residues on aquatic invertebrates and of diuron on algae in the Guayas wetlands were observed. Still, the exposure results indicated that the health risk for the consumers of the commercial red mangrove crab is low concerning cadusafos, chlorpyrifos, diuron, linuron, and pyrimethanil residues in crab tissues. The findings presented in this research can provide a useful basis for local water managers and environmental conservation groups to act and reduce the usage of pesticides, to avoid threatening aquatic and human health.


Asunto(s)
Braquiuros , Plaguicidas , Contaminantes Químicos del Agua , Animales , Ecosistema , Ecuador , Monitoreo del Ambiente , Estuarios , Humanos , Plaguicidas/análisis , Medición de Riesgo , Ríos , Contaminantes Químicos del Agua/análisis
14.
Anal Bioanal Chem ; 413(23): 5849-5857, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34327563

RESUMEN

Abundant studies have been published evaluating different parameters of reverse-phase liquid chromatography (LC) and supercritical fluid chromatography (SFC), both coupled to electrospray (ESI)/mass spectrometry (MS) for pesticide residue analysis. However, there is a lack of a comprehensive comparative study that facilitates deep knowledge about the benefits of using each technique. In the present study, the same mass spectrometer was used coupled to both liquid and supercritical fluid chromatographies with a multiresidue method of 215 compounds, for the analysis of pesticide residues in food samples. Through the injection of the spiked extracts, separate experiments were conducted. A study of the optimum ion source temperature using the different chromatography modes was performed. The results were evaluated in terms of sensitivity with tomato, leek, onion, and orange as representative fruit and vegetable matrices. The compounds which reported the highest area values in each chromatography were evaluated through their substance groups and polarity values. The impact of matrix effects obtained in tomato matrix was similar for both cases; however, SFC clearly showed better results in analyzing matrices with a higher number of natural co-extracted compounds. This can be explained by the combination of two effects: (i) chromatography separation and (ii) ion source efficiency. The chromatographic elution presented different profiles of matrix components, which had diverse impact on the coelution with the analytes, being more beneficial when SFC was used in the matrices studied. The data showed that the best results obtained in SFC are also related to a higher ionization efficiency even when the ESI emitter tip was not optimized for SFC flow. In the present study a comprehensive evaluation of the benefits and drawbacks of these chromatography modes for routine pesticide residue analysis related to target compounds/commodities is provided.


Asunto(s)
Cromatografía Liquida/métodos , Cromatografía con Fluido Supercrítico/métodos , Residuos de Plaguicidas/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos , Residuos de Plaguicidas/normas , Estándares de Referencia
15.
Carbohydr Polym ; 260: 117770, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712128

RESUMEN

Chitin-derived three-dimensional nanomaterials has tremendous potential in pesticide residue analysis as an attractive green substitute for toxic solvents. The work presented herein focuses on constructing the environmentally friendly nitrogen-containing chitin-derived carbon microspheres (N-CCMP) for the efficient adsorption of neonicotinoid pesticides (NPs) including acetamiprid, clothianidin, imidacloprid and thiamethoxam. The N-CCMP displayed hierarchical porous structure, uniform size distribution, and excellent specific surface area of 680.8 m2 g-1. The N-CCMP with N-heterocyclic ring structure and surface oxygen functional groups exhibited good affinity to NPs, which was beneficial for the rapid adsorption. Then, the N-CCMP were utilized as sorbent in extraction of NP residues. Under the optimum conditions, the relative recoveries in water and juice sample were in the range of 85 %-116 % and 74 %-108 %, with relative standard deviations (RSDs) of 0.1 %∼5.2 % and 0.7 %∼5.2 %, respectively. The extraction performance of N-CCMP were still over 80 % after 5 times of reuse.


Asunto(s)
Carbono/química , Quitina/química , Microesferas , Neonicotinoides/química , Nitrógeno/química , Residuos de Plaguicidas/química , Adsorción , Cromatografía Líquida de Alta Presión , Agua Dulce/análisis , Jugos de Frutas y Vegetales/análisis , Neonicotinoides/análisis , Residuos de Plaguicidas/análisis , Porosidad , Espectrometría de Masas en Tándem
16.
Talanta ; 225: 121983, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33592731

RESUMEN

A new hydrophobic deep eutectic solvent (DES) composed of thymol and vanillin (1:1) was prepared and used as the extraction solvent in vortex-assisted emulsification liquid-liquid microextraction of 16 pesticides in olive oil before GC-µECD analysis. Due to the complexity of oil samples, a DES-based liquid-liquid solvent system (n-hexane/acetonitrile/DES) was developed to achieve an effective clean-up. Among the four examined hydrophilic DESs, [choline chloride]:[urea] led to improved sensitivity, and clean chromatograms with low noise and drift from the sample matrix. Besides, the effect of the significant factors such as extraction solvent volume, pH, ionic strength, and vortex time was investigated. At the optimized conditions, the validation parameters such as linear range 0.04-250 µg kg-1, the limits of detection of 0.01-0.08 µg kg-1, intra-day, and inter-day relative standard deviations (RSDs) < 6.8 and < 9.7%, were obtained. This method was followed by GC-µECD and applied to determine pesticides in five olive oil samples. The relative recoveries were in the range of 63.1-119.4%.

17.
Food Chem ; 344: 128570, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33199122

RESUMEN

Novel SERS substrates is urgently in demand for rapid and sensitive analysis of toxic agrochemicals from food. In this work, a monodispersed tungsten disulfide quantum dots modified silver nanosphere (Ag@WS2QD) was prepared and used as SERS substrate. Ag@WS2QD generated uniform and stable SERS signals within 2 min, displaying great promise in "mixing and reading" detection. Compared to unmodified colloidal silver nanoparticles, 4 times higher analytical enhancement factor was found in Ag@WS2QD. Density functional theory calculation verified the enhanced charge transfer within the coupling systems of molecule-Ag@WS2QD. Besides, the unique surface properties are beneficial for the enrichment of specific molecule. Both the chemical extraction and enhanced charge transfer contributes to rapid and sensitive SERS detection of Ag@WS2QD. A "mixing and reading" SERS method for thiram from honey and four kinds of juice was developed from Ag@WS2QD, showing great promise for rapid and direct SERS detection for toxic agrochemicals and further applications.


Asunto(s)
Bebidas/análisis , Miel/análisis , Límite de Detección , Plata/química , Espectrometría Raman/métodos , Sulfuros/química , Tiram/análisis , Compuestos de Tungsteno/química , Transporte de Electrón , Análisis de los Alimentos , Puntos Cuánticos/química
18.
Food Chem ; 342: 128336, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33077280

RESUMEN

Polypyrrole magnetic microspheres were synthesized and used to extract carbaryl, carbofuran, and methomyl before analysis by a high-performance liquid chromatography with diode array detection. Under optimal conditions, four times the preconcentration was achieved with the use of only 1.2 mL of sample. Good linearity with ranges of 3.0-7.5 × 103, 6.0-4.5 × 103, and 15-3.0 × 103 ng kg-1 and limits of detection of 1.37 ± 0.10, 4.7 ± 1.2, and 10.1 ± 5.7 ng kg-1 were obtained, respectively. Good reproducibility (RSDs < 5%) was achieved over 24 cycles of extraction and regeneration. Good accuracy (recoveries 81.6 ± 1.5%-108.3 ± 2.2%) and good precision (RSDs 0.11%-4.5%) were obtained. Carbaryl was detected in apple (2.75 ± 0.23 ng kg-1), carbofuran in tomato (11.34 ± 0.61 ng kg-1), and methomyl in watermelon (34.7 ± 1.7 ng kg-1). The relative expanded uncertainty of the measurement method was less than 14% for all three pesticides.


Asunto(s)
Carbonato de Calcio/química , Carbamatos/aislamiento & purificación , Citrullus/química , Imanes/química , Microesferas , Plaguicidas/aislamiento & purificación , Solanum lycopersicum/química , Carbamatos/química , Técnicas de Química Sintética , Límite de Detección , Plaguicidas/química , Polímeros/química , Pirroles/química , Reproducibilidad de los Resultados
19.
Biosens Bioelectron ; 174: 112819, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33246678

RESUMEN

2,3,9,10,16,17,23,24-Octakis (4-methyl-2,6-bis((prop-2-yn-1-yloxy)methyl)phenoxy) phthalocyaninato zinc(II) (Pc) bearing sixteen terminal ethynyl groups was synthesized and attached to SWCNT (Single-walled carbon nanotube) covalently to obtain three dimensional porous hybrid material (SWCNT-Pc 3D) and its copper complex (Cu-SWCNT-Pc 3D). The structural characterization and electrochemical sensor features of the Cu-SWCNT-Pc hybrid towards to physostigmine pesticide were performed. A fast, direct and suitable determination method for physostigmine detection was offered. The designed sensor, Cu-SWCNT-Pc 3D/GCE (glassy carbon electrode) shows sensitivity ca 1.8, 4.3 and 2.8 times more than that of SWCNT/GCE, SWCNT-Pc-noncovalent/GCE and SWCNT-Pc 3D/GCE in terms of peak heights while bare and Pc/GCE had almost no voltammetric response to 2 µM physostigmine in PBS at a pH of 7.0. The limit of detection and quantification of physostigmine determination with Cu-SWCNT-Pc 3D/GCE were found to be 53 and 177 nM in the range of 0.1-4.8 µM, respectively. This study demonstrated that the modification of the GCE with Cu-SWCNT-Pc 3D as an electrochemical sensor was acted as catalytic role toward physostigmine presence of other interfering pesticides as high sensitivity and selectivity. The electrochemical determination of physostigmine in real samples was performed under the optimized conditions, also accuracy of the electrochemical determination method was evaluated with HPLC as a standard determination method.


Asunto(s)
Técnicas Biosensibles , Nanotubos de Carbono , Plaguicidas , Cobre , Electrodos , Indoles , Isoindoles , Límite de Detección , Fisostigmina , Zinc
20.
Talanta ; 223(Pt 1): 121714, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33303162

RESUMEN

Serious difficulties in evaluating the fungicides captan and folpet by the usual chromatography systems coupled to mass spectrometry are well known. These compounds are highly prone to degradation due to different conditions into tetrahydrophthalimide (THPI) and phthalimide (PHI). Such an effect can be produced at different stages of the analytical procedure or during the growing crop, making their evaluation troublesome. As a consequence, the quantification of captan and folpet is typically performed through or together these metabolites. However, imide ring metabolites can be produced by other unknown sources, including other phthalimide derived pesticides enabling false positive results. For this reason, in the last decade, laboratories demand a robust method to quantify captan and folpet, that overcomes such a situation. In the present work, various operational parameters were optimized to ensure the no degradation of captan and folpet facilitated by supercritical fluid chromatography coupled to mass spectrometry (SFC-MS/MS). A direct comparison with reverse-phase LC-MS/MS and GC-MS/MS was conducted for comparative purposes. The representative commodities selected for this evaluation were pepper and tomato. Furthermore, possible oxidative degradation during the sample milling step was also evaluated and avoided by the application of crio-milling conditions and ascorbic acid addition. By the proposed procedure, captan and folpet were recovered in both matrices at the 84%-105% range and with an RSD below 8% at two concentration levels: 10 and 50 µg/kg. On the contrary, with GC-MS/MS, captan and folpet were not recovered, and, as a consequence, their evaluation was possible only by THPI and PI. In the case of LC-MS/MS a significant decrease in the sensitivity was observed compared to SFC-MS/MS. Other validation parameters evaluated were satisfactory. This new approach can assess the correct analysis of captan and folpet at low concentrations in fruits and vegetables.

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