Simultaneous Determination of Five Neonicotinoid Insecticides in Edible Fungi Using Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-MS/MS)

Synthesis of multiwalled carbon nanotubes/metal-organic framework composite for the determination of neonicotinoid pesticides in medicine and food homology products

A novel extraction adsorbent composite of MWCNTs/NH2-MIL-101(Fe) was synthesized, and was used to extract 6 kinds of neonicotinoid pesticides in medicine and food homology products. The composite was characterized by scanning electron microscope (SEM), fourier transform-infrared (FT-IR) spectroscopy, and X-ray powder diffraction (XRD). MWCNTs were enveloped around MOFs to provide physical support for the crystal structure. The adsorbent has higher adsorption capacity and reusability than pure NH2-MIL-101(Fe). Combined with UPLC-MS/MS, the method showed the low limit of detection (LOD) and limit of quantitation (LOQ) of 0.01-0.07 μg/kg and 0.04-0.22 µg/kg, respectively. It exhibited high extraction recovery of 77.86-101.10% for neonicotinoid pesticides in spiked samples. Meanwhile, this novel method could be successfully employed for the detection of other medicine and food homology products. Compared with previous reports, this method has advantages in detection limit and extraction recovery, indicating that it can be a preferential choice for the detection of neonicotinoid pesticides.

Design of hydroxyl-functionalized nanoporous organic polymer with tunable hydrophilic-hydrophobic surface for solid phase extraction of neonicotinoid insecticides

As being widely used insecticides, neonicotinoid residues are toxic and harmful to human health and aquatic ecosystems. Thus, the sensitive monitoring of neonicotinoids in water and food samples is highly desirable to reduce their risks to humans. Herein, four novel hydroxyl-functionalized nanoporous organic frameworks (OH-NOP1, OH-NOP2, OH-NOP3 and OH-NOP4) with tunable hydrophilic-hydrophobic surface have been designed and fabricated for the first time by employing luteolin as monomer and 4,4'-bis(chloromethyl)-1,1'-biphenyl as crosslinker at the molar ratio of 3:1, 1:1, 1:3 and 1:6, respectively. When the molar ratio of luteolin to crosslinker was 1:3, OH-NOP3 was obtained and it presented the highest affinity with excellent adsorption performance towards the studied neonicotinoids. The adsorption mechanism was proposed to be the strong hydrogen bond, polar interaction, Lewis acid-base interaction and pore adsorption between OH-NOP3 and neonicotinoids. Then, utilizing OH-NOP3 as sorbent for solid phase extraction cartridges, an effective method for extraction and preconcentration of neonicotinoids followed by high performance liquid chromatography analysis has been developed for quantitative detection of neonicotinoids from water and edible fungi. The method provided good linearity over the range of 0.06-100.0 ng mL^-1 for lake water, 1.5-100.0 ng g^-1 for pleurotus eryngii and sea-shroom. Low detection limit (at the signal to noise ratio of 3) was achieved in the range of 0.02-0.08 ng mL^-1 for water, 0.50-0.60 ng g^-1 for pleurotus eryngii and 0.50-0.80 ng g^-1 for sea-shroom, while the limit of quantification was 0.06-0.25 ng mL^-1, 1.50-1.80 ng g^-1 and 1.50-2.50 ng g^-1, respectively. Satisfactory method recoveries (85.1-112%) were obtained, with relative standard deviations below 8.2%. This study offered a new strategy for designing efficient sorbents to adsorb or remove organic pollutants based on the structure and properties of substrates.

Method Development and Validation of Seven Pyrethroid Insecticides in Tea and Vegetable by Modified QuEChERS and HPLC-MS/MS

This study developed a quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure for determining seven pyrethroid pesticide residues in tea, cucumber, and tomato via high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The overall average recoveries of the seven pyrethroids were 72%-104% (relative standard deviation (RSD); 2.0%-16.1%, 89%-109% (RSD; 0.7%-17.3%), 82%-110% (RSD; 1.6%-17.1%) for tea, cucumber and tomato, respectively. The determination coefficient (R²), the limit of detection (LOD), and the limit of quantification (LOQ) were ≥ 0.99, 0.007-1.875 μg kg^-1, and 0.025-6.250 μg kg^-1, respectively. The method was successfully used to monitor the pyrethroid pesticide residues in market samples. HPLC-MS/MS rapidly, sensitively, and accurately determined the pyrethroid pesticide residues.

A porous boron nitride nanorods-based QuEChERS analysis method for detection of five neonicotinoid pesticide residues in goji berries

To accurately determine neonicotinoid pesticide residues in goji berries, porous boron nitride nanorods (p-BNNRs) were prepared and used as a new QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) clean-up sorbent. Combined with ultrahigh-pressure liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), a modified QuEChERS method was developed to determine five neonicotinoid pesticide residues in goji berries. In goji berries, the p-BNNRs were shown to have a greater clean-up ability than typical clean-up materials (C18, PSA) The recoveries of the five targets ranged from 78.1 to 117.3% at three fortified levels, and the LODs ranged from 2.2 to 3.7 μg kg^-1. The results indicate that this approach could be successfully used to quickly determine of the five neonicotinoid insecticide residues in goji berries for risk assessment purposes, demonstrating the applicability and suitability of p-BNNRs for the routine evaluation of neonicotinoid insecticide residues in goji berries.

Simultaneous determination of spirodiclofen, spiromesifen, and spirotetramat and their relevant metabolites in edible fungi using ultra-performance liquid chromatography/tandem mass spectrometry

A fast, sensitive, and reliable analytical method was developed and validated for simultaneous identification and quantification of spirodiclofen, spiromesifen, and spirotetramat and their relevant metabolites in edible fungi by ultra-performance liquid chromatography/tandem mass spectrometry (UHPLC–MS/MS). First, sample extraction was done with acetonitrile containing 1% formic acid followed by phase separation with the addition of MgSO₄:NaOAc. Then, the supernatant was purified by primary secondary amine (PSA), octadecylsilane (C18), and graphitized carbon black (GCB). The linearities of the calibrations for all analytes were excellent (R² ≥ 0.9953). Acceptable recoveries (74.5–106.4%) for all analytes were obtained with good intra- and inter- relative standard deviations of less than 14.5%. The limit of quantification (LOQs) for all analytes was 10 μg kg⁻¹. For accurate quantification, matrix-matched calibration curve was applied to normalize the matrix effect. The results indicated that the method was suitable for detecting the three acaricides and their relevant metabolites in edible fungi.

Imidacloprid dissipation, metabolism and accumulation in Agaricus bisporus fruits, casing soil and compost and dietary risk assessment

An improved understanding of imidacloprid (IMI) metabolism and accumulation in casing soil or compost-mushroom systems will help to optimise the safe use of IMI for agricultural pest control in Agaricus bisporus cultivation. In this study, the dissipation, metabolites and accumulation of IMI in casing soil or compost-A. bisporus systems were investigated. The results show that the IMI dissipation half-lives at doses of 10 and 50 mg kg^-1 were 65 d and 59 d in casing soil and 6.6 d and 6.2 d in compost, respectively during the cultivation period. Three IMI metabolites were observed in casing soil during cultivation of mushrooms. Urea-imidacloprid (IMI-urea) was a major metabolite, accounting for more than 59%. In compost, the main metabolite in the first 5 days was IMI-urea, from 5 to 10 days olefin-imidacloprid (IMI-ole) and 6-chloronicotinic acid (6-CNA) were both the most prominent compounds, and after 10 days 6-CNA alone. At 50 mg kg^-1 dose, IMI and the metabolites (IMI-urea, IMI-ole) were detected in the fruiting body with IMI applied to casing soil and only the metabolite 6-CNA was detected in fruiting body with IMI applied to compost. The bio concentration factors (BCFs) of IMI-ole and IMI-urea were higher than of IMI and 6-CNA, and the BCFs had no obvious relationship with log K_ow. Furthermore, the potential dietary risk of IMI in A. bisporus was acceptable when application rates in casing soil or compost was up to 50 mg kg^-1. Our study supports a safe use of IMI as agricultural pest control in A. bisporus cultivation.

Development and validation of a method for the analysis of five diamide insecticides in edible mushrooms using modified QuEChERS and HPLC-MS/MS

In this study, a new method for simultaneous determination of cyantraniliprole, chlorantraniliprole, tetrachlorantraniliprole, cyclaniliprole and flubendiamide in edible mushrooms by high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) combined with a modified QuEChERS procedure. The samples were extracted using acetonitrile and then cleaned up by primary secondary amine (PSA) and octadecylsilane (C18). The determination of these insecticides was achieved in less than 5 min using an electrospray ionization source in positive mode (ESI+) for cyantraniliprole and chlorantraniliprole, while negative mode (ESI-) for tetrachlorantraniliprole, cyclaniliprole and flubendiamide. The linearities of the calibrations for all target compounds were acceptable (R² ≥ 0.9922). The limits of detection and quantification were 0.05-2 μg kg^-1 and 5 μg kg^-1, respectively. Acceptable recoveries (73.5-110.2%) were acquired for these insecticides with RSDs less than 12.7%. The results demonstrated that the proposed method was effective and convenient for the determination of these insecticides in edible mushrooms.

Method development and validation of ten pyrethroid insecticides in edible mushrooms by Modified QuEChERS and gas chromatography-tandem mass spectrometry

A method for simultaneous determination of ten pyrethroid insecticides residues in edible mushrooms was developed. The samples were pretreated by a quick, easy, cheap, effective, rugged (QuEChERS) method. The ten pyrethroid insecticides were extracted from six kinds of edible mushrooms using acetonitrile and subsequently cleaned up by octadecylsilane (C18) or primary secondary amine (PSA). Instrumental analysis was completed in 16 min using gas chromatography-tandem mass spectrometry (GC-MS/MS). The overall average recoveries in the six kinds of edible mushrooms at three levels (10, 100 and 1000 μg kg^-1) ranged from 72.8% to 103.6%. The intraday and interday relative standard deviations (RSD) were lower than 13.0%. The quantification limits were below 5.57 μg kg^-1 in different matrices. The results demonstrated that the method is convenient for the quick detection of pyrethroid insecticides in edible mushrooms.

Automated Photochemically Induced Method for the Quantitation of the Neonicotinoid Thiacloprid in Lettuce

In this work, we present an automated luminescence sensor for the quantitation of the insecticide thiacloprid, one of the main neonicotinoids, in lettuce samples. A simple and automated manifold was constructed, using multicommutated solenoid valves to handle all solutions. The analyte was online irradiated with UV light to produce a highly fluorescent photoproduct (λexc/λem = 305/370 nm/nm) that was then retained on a solid support placed in the flow cell. In this way, the pre-concentration of the photoproduct was achieved in the detection area, increasing the sensitivity of the analytical method. A method-detection limit of 0.24 mg kg-1 was achieved in real samples, fulfilling the Maximum Residue Limit (MRL) of The European Union for thiacloprid in lettuce (1 mg kg-1). A sample throughput of eight samples per hour was obtained. Recovery experiments were carried out at values close to the MRL, obtaining recovery yields close to 100% and relative standard deviations lower than 5%. Hence, this method would be suitable for routine analyses in quality control, as an alternative to other existing methods.