Application of molecularly imprinted polymers to determine B1, B2, and B3 fumonisins in cereal products

The aim of this study was to develop an analytical method for qualitative and quantitative determination of the B₁, B_2, and B₃ fumonisins in cereal products. A LC coupled to an IT‐MS was used as the analytical instrument. The AFFINIMIP FumoZON Molecularly Imprinted Polymer SPE cartridges (Polyintell) were used to isolate fumonisins from the analyzed samples and the clean‐up step. Statistical parameters evaluated in some validation experiments were as follows: mean recovery 95–106%, precision <17% (expressed as recovery RSD). The developed method was used to determine fumonisins in 49 cereals (42 maize‐based and seven wheat‐based products). In most cases, concentrations of the studied compounds found in the analyzed samples were low. The highest total concentration of the B₁, B₂, and B₃ fumonisins was found in maize flour samples (range, 26–1102 μg/kg, mean 498 μg/kg).     

Rapid screening of amitraz and its metabolite residues in honey using a quick,easy, cheap,effective, rugged,and safe extraction method coupled with UHPLC and Q Exactive

A method for determining amitraz and 2,4‐dimethylaniline in honey was established by using ultra‐high‐performance liquid chromatoghaphy and Q Exactive after applying quick, easy, cheap, effective, rugged, and safe extracting process. A suitable extraction method was designed to extract the amitraz and 2,4‐dimethylaniline after a suitable amount of honey samples was dissolved. A Thermo Syncronis C₁₈ column (100 × 2.1 mm, 1.7 μm) was used for chromatographic separation of the samples. Then the two compounds were quantitatively analyzed via a program of Q Exactive. The linearity of amitraz and 2,4‐dimethylaniline was good in the concentration range of 0.5–100 μg/L, and the correlation coefficient R² was >0.99. The average recovery and relative standard deviation of each component were 81.3–90.0% and 5.1–7.2%. The 24‐ and 48‐h test results showed that the sample needed to be tested within 24 h. The limit of detection was 0.1 μg/kg for amitraz and 2,4‐dimethylaniline, whereas for both the limit of quantitation was 0.3 μg/kg.     

Physiochemical properties and novel biological applications of Callistemon viminalis‐mediated α‐Cr2O3 nanoparticles

We report an eco‐friendly synthesis of α‐Cr₂O₃ nanoparticles (NPs) using Callistemon viminalis (Bottle Brush) flower extracts as an efficient reducing and capping agent. NPs of sizes 15 nm and 17 nm were synthesized by annealing them at 400°C and 500°C, respectively, which were characterized by X‐ray diffraction, UV–Vis, Fourier transform‐infrared, high‐resolution‐transmission electron microscopy/scanning electron microscopy, SAED, energy‐dispersive X‐ray spectroscopy and SQUID. Microplate‐based assay was used for examining antibacterial potential against 12 pathogenic bacterial strains, and their minimum inhibitory concentrations were calculated. MTT cytotoxic assay was accomplished on Leishmania tropica amastigotes and promastigotes, which revealed IC₅₀ values of 44 μg/ml and 10.56 μg/ml, respectively. An IC₅₀ value of 46.32 μg/ml was obtained for HepG2 cancer cells. Enzyme inhibition studies indicated good acetylcholinesterase, moderate butyrylcholinesterase and low alpha‐glucosidase inhibition. Hemolytic assay indicated hemocompatibility at low concentration. In addition, good DPPH radical scavenging and moderate reducing power and total antioxidant potential was revealed by α‐Cr₂O₃ NPs.     

Characterization and application of a lanthanide‐based metal–organic framework in the development and validation of a matrix solid‐phase dispersion procedure for pesticide extraction on peppers (Capsicum annuum L.) with gas chromatography–mass spectrometry

The metal–organic framework [(La_0.9Sm_0.1)₂(DPA)₃(H₂O)₃]_∞ was synthetized and characterized by X‐ray diffractometry, differential thermogravimetric analysis, and infrared spectroscopy. The material was tested for the development and validation of a matrix solid‐phase dispersion procedure for extraction of atrazine, bifenthrin, bromuconazole, clofentezine, fenbuconazole, flumetralin, procymidone, and pirimicarb, from peppers, with analysis using gas chromatography with mass spectrometry in the selected ion monitoring mode. The method developed was linear over the range tested (50.0–1000.0 μg/kg for procymidone and 200.0–1000.0 μg/kg for all other pesticides), with correlation coefficients ranging from 0.9930 to 0.9992. Experiments were carried out at 250.0, 500.0, and 1000.0 μg/kg fortification levels, and resulted in recoveries in the range of 52.7–135.0%, with coefficient of variation values between 5.2 and 5.4%, respectively, for [(La_0.9Sm_0.1)₂(DPA)₃(H₂O)₃]_∞ sorbent. Detection and quantification limits ranged from 16.0 to 67.0 μg/kg and from 50.0 to 200.0 μg/kg, respectively, for the different pesticides studied. The results were compared with literature data. The developed and validated method was applied to real samples. The analysis detected the presence of residues of pesticides procymidone, fenbuconazole, flumetralin, clofentezine, atrazine, and bifenthrin.     

Biological Applications of Synthesized ZnO Nanoparticles Using Pleurotus djamor Against Mosquito Larvicidal,Histopathology, Antibacterial,Antioxidant and Anticancer Effect

The present study pertained to biosynthesis, characterization and biomedical application (larvicidal, histopathology, antibacterial, antioxidant and anticancer activity) of Zinc oxide nanoparticles (ZnONPs) from Pleurotus djamor. The synthesized NPs were characterized using spectral and microscopic analyses and further confirmed by UV–Visible spectrophotometer with apeak of 350 nm. The ZnONPs showed strong antioxidant property (DPPH, H₂O₂ and ABTS⁺ radical assay) and expressed good larval toxicity against Ae. aegypti and Cx. quinquefasciatus (IVth instar larvae) with the least LC₅₀ and LC₉₀ values (10.1, 25.6 and 14.4, 31.7 mg/l) after 24 h treatment, respectively. We noticed the morphological changes (damaged anal papillae area and the cuticle layers) in the treated larvae. For the antibacterial assay, the highest growth inhibition zone was recorded in C. diphteriae (28.6?±?0.3 mm), followed by P. fluorescens (27?±?0.5 mm) and S. aureus (26.6?±?1.5 mm). The in vitro cytotoxicity assay depicted a significant level of cytotoxic effects (LC₅₀ values 42.26 μg/ml) of ZnONPs against the A549 lung cancer cells, even at low dose. The overall findings of the study suggest that P. djamor had the ability for the biosynthesis of ZnONPs and could act as an alternative biomedical agent for future therapeutic applications in medical avenues.

     

Synthesis and application of a T-2 toxin imprinted polymer

The synthesis of a T-2 toxin imprinted polymer and its application in food analysis are reported for the first time. A molecularly imprinted polymer (MIP) for the selective recognition of T-2 toxin (T-2) was synthesized by bulk polymerization. Methacrylamide and ethyleneglycol dimethacrylate were applied as functional monomer and cross-linker, respectively. Molecularly imprinted solid-phase extraction (MISPE) procedures were optimized for further application in the analysis of T-2. Scatchard plot analysis revealed that two classes of imprinted binding sites were formed in the imprinted polymer. The dissociation constant (K_D) of the higher affinity binding sites was 7.0 μmol/l, while the K_D of the lower affinity binding sites was 54.7 μmol/l. The performance of the MIP throughout the clean-up of spiked maize, barley and oat sample extracts was compared with the results obtained when using non-imprinted polymer, OASIS HLB^® and immunoaffinity columns (IAC). Depending on the food matrix and the spiked concentration, recoveries after MISPE and non-imprinted solid-phase extraction varied respectively from 60% to 73% and from 21% to 57%. Recoveries obtained after clean-up using OASIS HLB^® and IAC were in the range of 74–104% and 60–85%, respectively. Although highest recoveries were obtained with OASIS HLB^® sorbents, the designed MIP and the IAC were superior regarding selectivity, cross-reactivity, matrix effect, limits of detection (LOD) and limits of quantification (LOQ). Depending on the matrix, LOD after MISPE ranged from 0.4 μg/kg to 0.6 μg/kg and LOQ from 1.4 μg/kg to 1.9 μg/kg. LOD and LOQ after OASIS HLB^® clean-up varied from 0.9 μg/kg to 3.5 μg/kg and from 3.1 μg/kg to 11.7 μg/kg, respectively. The LOD and LOQ values obtained with IAC were in the range of 0.3–2.3 μg/kg and 1.0–7.7 μg/kg, respectively. Analysis of 39 naturally contaminated samples (maize, barley and oat) by liquid chromatography tandem mass spectrometry revealed that the MIP could be an excellent alternative for clean-up of contaminated food samples.     

Development of a Monoclonal Antibody-Based ELISA for the Detection of Sulfaquinoxaline in Chicken Tissues and Serum

Abstract

A monoclonal antibody (Mab) was produced by using sulfaquinoxaline-human serum albumin (SQX-HSA) conjugate as immunogen. The anti-SQX Mab exhibited negligible cross reactivity with other commonly used sulfonamides. Using this Mab, a competitive indirect enzyme-linked immunosorbent assay (ciELISA) was developed to detect SQX in chicken tissues and serum. The ciELISA showed a 50% inhibition (IC₅₀) value of 2.60 ng/mL. The recoveries of SQX from spiked chicken muscle, liver, and serum at levels of 5–50 µg/kg were 82.6–96.5%, 75.3–94.5%, and 69.7–89.3%, respectively. The coefficient variations (CVs) were 6.22–7.17%, 4.9–8.9%, and 1.20–10.15%, respectively. Detection limits were 1.29 µg/kg in muscle, 1.32 µg/kg in liver, and 2.44 µg/kg in serum.     

Phenolic,flavonoid contents,anticholinesterase and antioxidant evaluation of Iris germanica var; florentina

This study was designed to investigate antioxidant and anticholinesterase potential of Iris germanica var; florentina. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potential of plant samples were investigated by Ellman’s assay. Antioxidant activity was performed using DPPH, H₂O₂ and ABTS free radical scavenging assays. Total phenolics and flavonoids contents were expressed in mg GAE/g dry weight and mg RTE/g, respectively. In AChE inhibition assay, Ig.Fl, Ig.Sp and Ig.Cf fractions exhibited highest activity with IC₅₀ values of < 0.1, 5.64 and 19 μg/mL, respectively. In BChE inhibitory assay, Ig.Fl, Ig.Sp, Ig.Cf and Ig.Cr were most active with IC₅₀ of < 0.1, < 0.1, 31 and 78 μg/mL, respectively. In DPPH assay, Ig.Fl and Ig.Cf exhibited highest inhibition of free radicals, 80.52% (IC₅₀ = 9 μg/mL) and 78.30% (IC₅₀ = 8 μg/mL), respectively. In ABTS assay Ig.Cr, Ig.Cf, Ig.Fl and Ig.Sp exhibited IC₅₀ values of < 0.1, 2, 2 and 3 μg/mL, respectively.     

Greenness assessment of a stability indicating simple inexpensive high-performance thin-layer chromatography–dual wavelength method for simultaneous determination of mometasone furoate and salicylic acid in complex matrix using analytical eco-scale

A stability-indicating validated high-performance thin-layer chromatography method was performed for the determination of mometasone furoate (MM) and salicylic acid (SLY), simultaneously within the concentration range of 0.1–1.6 μg/band for MM and 0.4–5 μg/band for SLY. This method was developed to assay the investigated drugs in the presence of their degradation products by alkaline, acidic, neutral, photolytic, and oxidative degradation. Separation was achieved using dual wavelength system, 250 nm for MM and 300 nm for SLY, with mobile phase composed of chloroform–ethanol (9:1, %v/v) and stationary phase of aluminum plates pre-coated with silica gel 60 F₂₄₅. The proposed method is well used for the assay and separation of MM and SLY in pure form and Elicasal^® ointment. The developed method has many advantages such as being rapid, selective and inexpensive. Such advantages promote the suggested method for the high throughput assay of MM and SLY mixture, in pure form and topical preparation. The developed method was validated according to the International Council for Harmonisation guidelines, in terms of linearity, limits of detection and quantification, precision, accuracy, robustness, and specificity. Assessment of greenness has been performed depending on analytical eco-scale approach.

     

Development and Validation of a Modified QuEChERS Method for the Analysis of Bisphenols in Meats by UPLC-MS/MS

A reliable and affordable QuEChERS (quick, easy, cheap, effective, rugged, and safe) methodology in combination with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS) was successfully developed and validated for the determination of eight bisphenols (BPs) residues containing in meats (chicken, duck, beef, pork, fish, shrimp, and mutton). A novel QuEChERS method optimization was carried out in terms of process efficiency (PE), matrix effect (ME), and extraction recovery (RE). After a simple vortex extraction of the samples with acetonitrile, 1 g sodium acetate was used for salting out (NaAC), and 100 mg primary secondary amine (PSA) purifying reagents were used for purification. The properties of the sorbents were assessed by the obtained parameters, such as matrix effect (ME), linearity, sensitivity, accuracy, and precision. Under the optimal conditions, BPs were well separated on an ACQUITY UPLC BEH ® C₁₈ column in 8 min by gradient elution, and exhibited a good linear relationship (R²?>?0.9988) in the linear range. Moreover, the limits of detection (LODs) and the limits of quantification (LOQs) were located in the range of 0.01– 0.11 μg/kg and 0.03 – 0.37 μg/kg, respectively. The developed method was satisfactory in terms of accuracy (relative recoveries: 76.1% – 113.7%) and precision (relative standard deviations below 10.3%). Finally, the developed method was successfully employed to identify and quantify BPs residues in 28 real meat samples. The proposed QuEChERS-UPLC–MS/MS method is simple, high efficiency, cost-effective, practical, and susceptible to being implemented in routine laboratories to quickly detect the BPs in meats (chicken, duck, beef, pork, fish, shrimp, and mutton). In this sense, the method is useful for obtaining BPs residue data to evaluate the contamination status of BPs in meat food and provide scientific support for scientific supervision.

     

Incidence of Fusarium Mycotoxins in Wheat and Maize from Albania

In this study, ten Fusarium toxins were analysed in wheat and maize commodities from Albania. In total, 71 samples of wheat and 45 samples of maize were collected from different producing regions. The analytical procedure consisted of a simple one-step sample extraction followed by the determination of toxins using liquid chromatography coupled with tandem mass spectrometry. Fusarium toxins were found in 23% of the analysed wheat samples and in 78% of maize samples. In maize samples, most often fumonisins B₁ (FB1) and B₂ (FB2) were found. They were present in 76% of samples. They were detected in all positive samples except in one with concentrations ranging from 59.9 to 16,970 μg/kg. The sum of FB1 and FB2 exceeded the EU maximum permitted level (4000 μg/kg) in 31% of maize samples. In wheat samples, the only detected Fusarium mycotoxin was deoxynivalenol (DON), present in 23% of samples. In one sample with the concentration of 1916 μg/kg, the EU maximum permitted level (1250 μg/kg) was exceeded. This is the first report on the presence of Fusarium toxins in wheat and maize grains cultivated in Albania.     

Determination of cyclopiazonic acid in food and feeds by liquid chromatography–tandem mass spectrometry

A new, fast and efficient multiple reaction monitoring (MRM) high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) method for the determination of cyclopiazonic acid (CPA) in mixed feed, wheat, peanuts and rice is presented. The analytical methodology involves sample extraction with an alkaline methanol–water mixture, defatting with hexane and quantification using HPLC–MS/MS without further treatment of sample extracts. Reversed-phase liquid chromatography using a C18 stationary phase coupled to negative mode electrospray triple quadrupole tandem mass spectrometry was applied. The limit of detection was 5 μg/kg while the limit of quantification was 20 μg/kg in the matrices investigated. The detector response was found to be linear over the range 25–250 μg/kg in feed and 25–500 μg/kg in wheat, peanuts and rice. The mean overall recoveries (n = 18) of CPA varied from 79% to 114% in the range of concentrations studied over a period of 4 months. Mean recoveries (n = 3 or 6) of CPA in wheat, peanuts and rice varied from 70% to 111%, 77% to 116% and 69% to 92%, respectively. The method was successfully applied to the analysis of feed and rice samples artificially infected with the fungal strain Penicillium commune, where the toxin was found at different levels.     

Fluctuation in the ergosterol and deoxynivalenol content in barley and malt during malting process

This paper describes determination of the deoxynivalenol and ergosterol in samples from different varieties of barley and, consequently, malt produced from this barley. In total, 20 samples of barley and 20 samples of barley malt were analyzed. The alkaline hydrolysis with consequent extraction into hexane was applied to obtain the ergosterol from cereals. Extraction to acetonitrile/water and subsequent solid-phase extraction (SPE) were used for deoxynivalenol. The determination of the samples was performed on high-performance liquid chromatography using UV detection (ergosterol) and mass spectrometric detection (deoxynivalenol). The influence of the malting process on the production of two compounds of interest was assessed from obtained results. Ergosterol concentration ranged 0.88–15.87 mg/kg in barley and 2.63–34.96 mg/kg in malt, where its content increased to 95% compared to samples before malting. The malting process was observed as having a significant effect on ergosterol concentration (P = 0.07). The maximum concentration of deoxynivalenol was found to be 641 μg/kg in barley and 499 μg/kg in malt. Its concentration was lower than the legislative limit for unprocessed cereals (1,250 μg/kg). The statistic effect of the malting process on deoxynivalenol production was not found. Linear correlation between ergosterol and deoxynivalenol content was found to be very low (barley R = 0.02, malt R = 0.01). The results revealed that it is not possible to consider the ergosterol content as the indicator of deoxynivalenol contamination of naturally molded samples.     

Simultaneous analysis of tropane alkaloids in teas and herbal teas by liquid chromatography coupled to high‐resolution mass spectrometry (Orbitrap)

A new method has been developed for the simultaneous determination of 13 tropane alkaloids in tea and herbal teas using high‐performance liquid chromatography coupled to an Exactive‐Orbitrap analyzer. A mixture of methanol, water, and formic acid was used for the extraction of the target compounds followed by a solid‐phase extraction step. The validated method provided recoveries from 75 to 128% with intra‐ and interday precision lower than or equal to 24% (except for apoatropine). Limits of quantification ranged from 5 to 20 μg/kg. Eleven tea and herbal tea samples and two contaminated samples with Datura stramonium seeds were analyzed. Tropane alkaloids were detected in six samples with concentrations from 5 (apoatropine) to 4340 μg/kg (sum of physoperuvine, pseudotropine, and tropine), whereas concentrations from 5 (apoatropine) to 1725 μg/kg (sum of physoperuvine, pseudotropine, and tropine) were found in the contaminated samples.     

Ciprofloxacin‐isatin‐1H‐1,2,3‐triazole Hybrids: Design,Synthesis, and in vitro Anti‐tubercular Activity against M. tuberculosis

A new set of ciprofloxacin (CPFX)‐isatin‐1H‐1,2,3‐triazole hybrids 6a – l with greater lipophilicity compared with the parent CPFX was designed, synthesized, and assessed for their in vitro anti‐mycobacterial activity against Mycobacterium tuberculosis (MTB) H₃₇Rv as well as cytotoxicity in VERO cell line. The preliminary results showed that all hybrids (MIC: 0.39–50 μg/mL) exhibited promising activities against MTB H₃₇Rv, and six of them (MIC: 0.39–1.56 μg/mL) were more active than the parent CPFX (MIC: 3.12 μg/mL). In particular, the most active conjugate 6h (MIC: 0.39 μg/mL) was comparable with RIF (MIC: 0.39 μg/mL), and eight times more potent than CPFX. All conjugates (CC₅₀: 4–64 μg/mL) were more toxic than the parent (CC₅₀: 128 μg/mL) in VERO cell lines, and the most active hybrids, which also displayed the highest cytotoxicity, should be further optimized.     

1H‐1,2,3‐triazole‐tethered 8‐OMe Ciprofloxacin and Isatin Hybrids: Design,Synthesis and in vitro Anti‐mycobacterial Activities

A new class of 1H ‐1,2,3‐triazole‐tethered 8‐OMe ciprofloxacin (8‐OMe CPFX) isatin hybrids 5a–l was designed, synthesized and screened for their in vitro anti‐mycobacterial activities against Mycobacterium tuberculosis H₃₇Rv and multi‐drug‐resistant tuberculosis (MDR‐TB). All targets (minimum inhibitory concentration (MIC): 0.20–8.0 μg/mL) exhibited promising inhibitory activity against MTB H₃₇Rv and MDR‐TB. Among them, conjugate 5h (MIC: 0.20 μg/mL), was 2–16 times more potent in vitro than the references CPFX (MIC: 3.12 μg/mL), 8‐OMe CPFX (MIC: 1.56 μg/mL) and RIF (MIC: 0.39 μg/mL) against MTB H₃₇Rv. The most potent hybrid 5l (MIC: 0.25 μg/mL) was 8–256 times more active than the three references (MIC: 2.0–64 μg/mL) against MDR‐TB. Both of them warrant further investigations.     

Microwave‐Assisted Synthesis and Antituberculosis Screening of Some 4‐((3‐(Trifluoromethyl)‐5,6‐dihydro‐[1,2,4]triazolo[4,3‐a]pyrazin‐7(8H)‐l)methyl)benzenamine Hybrids

In the present investigation, a series of 4‐((3‐(trifluoromethyl)‐5,6‐dihydro‐[1,2,4]triazolo[4,3‐a]pyrazin‐7(8H)‐yl)methyl)benzenamine analogs 6a–o were synthesized and characterized by IR, NMR (¹H and ¹³C), and mass spectra. All newly synthesized compounds 6a–o were prepared under conventional and microwave irradiation methods. These compounds obtained in higher yields and in shorter reaction times in the microwave irradiation method when compared with the conventional method. Synthesized compounds 6a–o were inspected for their in vitro antitubercular activity against Mycobacterium tuberculosis H₃₇Ra using an established XTT reduction menadione assay. Among the screened compounds, 6i (IC₅₀: 1.82 μg/mL), 6j (IC₅₀: 1.02 μg/mL), and 6k (IC₅₀: 1.59 μg/mL) showed excellent activity. Furthermore, compound 6i showed MIC₉₀ value of 16.02 μg/mL. In summary, the results indicate the identification of some novel, selective, and specific inhibitors against M. tuberculosis that can be explored further for the potential antitubercular drug.     

Determination of 19 sulfonamides residues in pork samples by combining QuEChERS with dispersive liquid–liquid microextraction followed by UHPLC–MS/MS

A new simple and rapid pretreatment method for simultaneous determination of 19 sulfonamides in pork samples was developed through combining the QuEChERS method with dispersive liquid–liquid microextraction followed by ultra‐high performance liquid chromatography with tandem mass spectrometry. The sample preparation involves extraction/partitioning with QuEChERS method followed by dispersive liquid–liquid microextraction using tetrachloroethane as extractive solvent and the acetonitrile extract as dispersive solvent that obtained by QuEChERS. The enriched tetrachloroethane organic phase by dispersive liquid–liquid microextraction was evaporated, reconstituted with 100 μL acetonitrile/water (1:9 v/v) and injected into an ultra‐high performance liquid chromatography with a mobile phase composed of acetonitrile and 0.1% v/v formic acid under gradient elution and separated using a BHE C₁₈ column. Various parameters affecting the extraction efficiency were investigated. Matrix‐matched calibration curves were established. Good linear relationships were obtained for all analytes in a range of 2.0–100 μg/kg and the limits of detection were 0.04–0.49 μg/kg. Average recoveries at three spiking levels were in the range of 78.3–106.1% with relative standard deviations less than 12.7% (n = 6). The developed method was successfully applied to determine sulfonamide residues in pork samples.     

Multiresidue method for the determination of 227 pesticides in hot pepper (Capsicum annuum L.) by liquid chromatography with tandem mass spectrometry†

A high‐throughput, rapid, and efficient modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method with a simple cleanup procedure has been developed for simultaneously determining 227 pesticides in pepper samples by liquid chromatography with tandem mass spectrometry (running time: 10 min). Pesticide residues were extracted/partitioned with an acetonitrile/DisQuE QuEChERS pouch, and the resulting samples were cleaned up with different methods: dispersive solid‐phase extraction with primary secondary amines or multiwalled carbon nanotubes and graphitized carbon solid mini cartridge column. The results indicated that multiwalled carbon nanotubes dispersive sorbents achieved the best recoveries and had less matrix interference. The numbers of pesticides with a recovery in the range of 70–120% were 199 at a spiked level of 40 μg/kg. The correlation coefficients (r²) for 227 pesticides were above 0.99, while the limits of quantitation of pesticides in pepper samples ranged from 0.13 to 13.51 μg/kg (S/N = 10), and the limits of detection ranged from 0.04 to 4.05 μg/kg (S/N = 3). The relative standard deviations of approximately 197 pesticides were below 20% at spiked levels of 40 μg/kg. Based on these results, the proposed method was chosen as the most suitable cleanup procedure for the determination of multiresidue pesticides in pepper samples.     

Performance comparison of dispersive solid‐phase extraction and multiplug filtration cleanup methods for the determination of tefuryltrione in plant and environmental samples using UHPLC–MS/MS

The detection frequencies of tefuryltrione, a new type of 4‐hydroxyphenyl‐pyruvate dioxygenase inhibitor herbicide, are rarely reported, probably because of the paucity of analytical methods. Herein, an effective and sensitive analytical method has been developed to detect tefuryltrione in vegetables (tomato and cucumber), cereals (rice and corn), soil, and water by ultra high performance liquid chromatography coupled with tandem mass spectrometry. Comparisons of the performances of dispersive solid‐phase extraction and multiplug filtration cleanup methods were carried out for tefuryltrione in complex matrices. Extraction solvents and purification sorbents were further optimized for dispersive solid‐phase extraction. Tefuryltrione was analyzed with electrospray ionization in the positive mode within 2.0 min. Mean recoveries for tefuryltrione were 75.4–108.9% with relative standard deviations less than 11.0% at three fortification levels (10, 100, 500 μg/kg) in the sample matrixes. Limits of quantification ranged from 0.70 to 5.12 μg/kg, and an excellent linearity (R ² ≥ 0.9902) was obtained for tefuryltrione at concentrations of 5–1000 μg/L. The results showed that the developed dispersive solid‐phase extraction method could serve as an effective, sensitive, and robust method for routine monitoring of tefuryltrione residue in plants and environmental samples.