Persistence of foliar applied and pre-storage seed-treated insecticides in rice and its processed products.

A field study was conducted to investigate the persistence of foliar-applied thiamethoxam 25% WG at a rate of 25 g ai ha-1 and chlorantraniliprole 18.5% SC at 30 g ai ha-1 in various parts of rice plants, including whole grain rice, brown rice, bran, husk, straw, and cooked rice. Liquid Chromatography-Mass spectrometry/Mass spectrometry was used for sample analysis. Chlorantraniliprole residues were found to persist in whole grains, bran, husk, and straw at the time of harvest, while thiamethoxam residue was not detected in harvested grains, processed products, or straw. The study concluded that foliar-applied chlorantraniliprole and thiamethoxam did not pose any dietary risk in cooked rice. In a pre-storage seed treatment study, thiamethoxam 30% FS at 3 mL kg-1 was evaluated against Angoumois grain moth infestation during storage. The seeds remained unharmed for nine months and exhibited significantly less moth damage (2.0%) even after twelve months of storage. Thiamethoxam residues persisted for more than one year in whole rice grain, brown rice, bran, and husk with seed treatment, with higher residue levels observed in bran and husk. Parboiling and cooking led to the degradation of thiamethoxam residues.

Determination of chlorantraniliprole for managing Helicoverpa armigera and Spodoptera litura in cotton ecosystem.

Cotton bollworm incidence and damages are high in India. In addition, it causes considerable yield loss. A new insecticide formulation Chlorantraniliprole 600 g/L SC was used along with recommended insecticides for managing Spodoptera litura and Helicoverpa armigera in two consecutive experimental trials during the period October 2021 to September 2022. Two foliar applications of Chlorantraniliprole (40 and 30 g a. i/ha) at ten days interval period reduced significantly the larval populations of H. armigera, S. litura without any phytotoxic symptoms in cotton. Chlorantraniliprole application in open field condition was found to be harmless to natural enemy (coccinellids and spiders). Even though, a temporary lessening of natural enemy populations was noticed after spray, progressively the population was increased within a week time. Cotton yield was high in chlorantraniliprole @ 40 g a. i/ha treated plot (22.66, 22.12 q/ha) when compared to untreated control. Similar effect was also noticed in the dose at 30 g a. i/ha (22.35, 21.81 q/ha) and it was statistically on par in both experiments. Residue analysis results confirming that, cotton lint, cotton seed and soil samples collected from treated (30 and 60 g a. i/ha) and untreated samples during harvest were free from chlorantraniliprole residues (below detectable levels of 0.008 µg/g).

Flagellin and elongation factor of Bacillus velezensis (VB7) reprogramme the immune response in tomato towards the management of GBNV infection.

The present study investigates the reprogramming of plant defense system, upon interaction with MAMP (Microbe Associated Molecular Pattern) gene products including, flagellin (Flg) and elongation factor (EF-Tu) of Bacillus velezensis (VB7) and groundnut bud necrosis virus (GBNV) in tomato (Shivam). The MAMP gene products induced the plant defense genes including, PAL, PPO, LOX, JAR, MYC2 and PDF 1.2. Secondary metabolites of Bacillus spp. at 1000 parts per million (ppm) concentration effectively reduced GBNV symptom expression in cowpea (CO7) up to 83.1 % compared to untreated, GBNV inoculated, control. The secondary metabolites from B. velezensis (VB7) and B. licheniformis (Soya 1) reduced GBNV symptoms in cowpea (CO7) up to 1.7 lesions/cm2 leaf area compared to 8.6 lesions/cm2 in virus inoculated control. Further, field study revealed that the combined application of B. velezensis (VB7) and B. licheniformis (Soya1) at 1% (10 mL/L) as, soil and foliar application reduced the percent disease incidence (PDI) up to 10.5 (PDI) compared to 28.4 (PDI) in untreated control plants. Besides, it also improved the plant growth and yield up to 23.5 tonnes/ha compared to 13.8 tonnes/ha in untreated control.

Analysis of tebuconazole residues in coconut water, kernel and leaves using LC-MS/MS.

A method was validated for determining tebuconazole residues in coconut water, kernel and leaves using Liquid chromatography-Mass spectrometry/Mass spectrometry (LC-MS/MS) with electro spray ionization in positive ion mode. Samples were extracted with acetonitrile and subsequent clean-up was done using dispersive solid phase extraction. Recovery ranged between 70 and 114.39 % and the RSD was between 0.64 and 10.24 %. Root feeding studies with tebuconazole @ 5 and 10 mL/100 mL of water/tree revealed the presence of tebuconazole residues in coconut leaves until three days after treatment but dissipated to below quantifiable limit on 5th day at single dose while the residues went below quantifiable limit after 10 days at double the dose. Residues were below quantifiable limit in coconut water and kernel until three days. Data obtained from the study were used for estimating the risks associated with the exposures to tebuconazole residues in coconut.

Sublethal and transgenerational effects of spinetoram on the biological traits of Plutella xylostella (L.) (Lepidoptera: Plutellidae).

Spinetoram, a spinosyn insecticide is used to manage lepidopteran pests, including diamondback moth, Plutella xylostella. In addition to determining the lethal effects, identifying low and/or sublethal effects of an insecticide is crucial to understanding the total impact of an insecticide. We assessed the low lethal and sublethal effects of spinetoram on two successive generations of P. xylostella. The initial bioassay results showed that spinetoram exhibited high toxicity against P. xylostella with an LC50 of 0.114 mg L-1 after 48 h exposure. The low lethal (LC25) and sublethal (LC10) concentrations of spinetoram showed significant reduction in pupation rate, pupal weight and adult emergence. The fecundity of F1 generation was significantly lower in LC25 (117.85 eggs/female) and LC10 (121.34 eggs/female) treated group than untreated control (145.32 eggs/female). The intrinsic rates of increase (r) was significantly lower (r = 0.1984 day-1) in spinetoram treated P. xylostella F1 progeny compared to untreated control (r = 0.2394 day-1). Our results suggest that LC10 and LC25 concentration of spinetoram might affect P. xylostella population growth by reducing its survival, development, and reproduction.

Visible-Light Driven Photocatalytic Degradation of Eosin Yellow (EY) Dye Based on NiO-WO3 Nanoparticles.

Herein, we report a simple synthesis, characterization and photocatalytic degradation application of composite NiO-WO3 nanoparticles. The nanoparticles were synthesized by facile low-temperature method and characterized by several techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis diffuse reflectance spectra (DRS). The synthesized NiO-WO3 nanoparticles were used as efficient photocatalyst for the photocatalytic degradation of Eosin yellow (EY) dye. Interestingly, the synthesized photocatalytic exhibited a significant visible-light driven photocatalytic degradation of Eosin yellow (EY) dye. Under optimized conditions (pH = 5, catalyst dosage = 3 µM and initial dye concentration= 1.0 g/L), the obtained photo degradation of EY dye was above 95% in 180 min under visible light irradiation. Remarkably, reusability of the prepared photocatalyst was also observed and the photo-degradation reactions follow the pseudo-first-order model.

Electrochemical sensing of nicotine using CuWO4 decorated reduced graphene oxide immobilized glassy carbon electrode.

A novel and selective electrochemical sensing of nicotine is studied using copper tungstate decorated reduced graphene oxide nanocomposite (CuWO4/rGO) nafion (Nf) immobilized GC electrode (GCE). The CuWO4/rGO nanocomposite is synthesized using sonication method and characterized by HR-TEM (High resolution transmission electron microscopy), SEM (Scanning electron microscopy), FT-IR (Fourier transform infrared spectroscopy), SAED (Selected area of electron diffraction pattern), XRD (X-ray diffraction), Raman spectroscopy, Thermo gravimetric analysis (TGA) and EDX (Energy dispersive X-ray diffraction) techniques. The CuWO4/rGO/Nf immobilized GCE shows better electrocatalytic response for the detection of nicotine as compared to bare GCE. A better selectivity and sensitivity is achieved using CuWO4/rGO/Nf immobilized GCE to detect 0.1 µM nicotine in the presence of 100-fold excess concentrations of different interferents. The present CuWO4/rGO/Nf immobilized GCE electrochemical sensor exhibits an ample range of sensing from 0.1 µM to 0.9 µM and the low detection limit is found to be 0.035 µM (S/N = 3). Comparable results are achieved for the determination of nicotine in various real samples such as cigarettes (Gold flake and Wills) and urine samples with improved recoveries.

Validation and quantification of neonicotinoid insecticide residues in rice whole grain and rice straw using LC-MS/MS.

An efficient analytical method was developed and validated using a modified QuEChERS method and LC-MS/MS for the detection and quantification of neonicotinoid insecticide residues in rice whole grain and rice straw. The samples were extracted using acetonitrile and cleaned up by dispersive solid-phase extraction. Validation based on five fortification levels showed good recoveries of neonicotinoids ranging from 75% to 116 % and 60% to 105 % for rice whole grain and straw, respectively. The precision ranged between 3% and 17 %, and 2% and 10 % for grain and straw, respectively. The limit of detection was from 0.007 to 0.0084 mg kg-1 and 0.005 to 0.15 mg kg-1 and the limit of quantification was in the range of 0.024-0.028 mg kg-1 and 0.016-0.051 mg kg-1 for rice whole grain and rice straw, respectively. Monitoring of farm gate samples indicated that, out of 24 samples, 1 rice whole grain sample was contaminated with thiamethoxam residues (0.07 mg kg-1).

Facile sonochemical synthesis of Zn2SnO4-V2O5 nanocomposite as an effective photocatalyst for degradation of Eosin Yellow.

This study presents a novel method for the preparation of Zn2SnO4/V2O5 nanocomposites via a sonochemical aqueous route. This method is mild, convenient, cheap and efficient. The as prepared samples were characterized by XRD, SEM, EDAX, TEM, BET, FT-IR and UV-DRS spectra. DRS spectrum shows the adsorption edge of Zn2SnO4-V2O5 in visible region of spectrum. The structural and morphological features of the as synthesized Zn2SnO4-V2O5 nanocomposites have been observed using both scanning and transmission electron microscopy. BET surface area analysis inferred that the prepared hetero-junctions are meso-porous in nature. The photocatalytic activity of Zn2SnO4-V2O5 nanocomposites for the degradation of Eosin Yellow (EY) dye under visible light was investigated in detail. 3% Zn2SnO4-V2O5 nanocomposite exhibited the highest photocatalytic performance (92% of EY degradation) when compared with 2% Zn2SnO4-V2O5 and 5% Zn2SnO4-V2O5. The adsorption of Eosin Yellow followed the pseudo-first order kinetic model. Simultaneously, high stability of the sample was also investigated by four successive photodegradation of EY under visible light. The relationship between photocatalytic activity and the structure of 3% Zn2SnO4-V2O5 nanocomposite is discussed, and possible reaction mechanisms are also proposed. Therefore, the facile sonochemical preparation process provides some insight into the application of Zn2SnO4-V2O5 nanocomposites in photocatalytic degradation of organic pollutants.

A novel highly selective and sensitive detection of serotonin based on Ag/polypyrrole/Cu2O nanocomposite modified glassy carbon electrode.

A silver/polypyrrole/copper oxide (Ag/PPy/Cu2O) ternary nanocomposite was prepared by sonochemical and oxidative polymerization simple way, in which Cu2O was decorated with Ag nanoparticles, and covered by polyprrole (PPy) layer. The as prepared materials was characterized by UV-vis-spectroscopy (UV-vis), FT-IR, X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM) with EDX, high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). Sensing of serotonin (5HT) was evaluated electrocatalyst using polypyrrole/glassy carbon electrode (PPy/GCE), polypyrrole/copper oxide/glassy carbon electrode (PPy/Cu2O/GCE) and silver/polypyrrole/copper oxide/glassy carbon electrode (Ag/PPy/Cu2O/GCE). The Ag/PPy/Cu2O/GCE was electrochemically treated in 0.1MPBS solution through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The peak current response increases linearly with 5-HT concentration from 0.01 to 250 µmol L-1 and the detection limit was found to be 0.0124 µmol L-1. It exhibits high electrocatalytic activity, satisfactory repeatability, stability, fast response and good selectivity against potentially interfering species, which suggests its potential in the development of sensitive, selective, easy-operation and low-cost serotonin sensor for practical routine analyses. The proposed method is potential to expand the possible applied range of the nanocomposite material for detection of various concerned electro active substances.

Ultrasonic assisted synthesis with enhanced visible-light photocatalytic activity of NiO/Ag3VO4 nanocomposite and its antibacterial activity.

The NiO/Ag3VO4 nanocomposite photocatalysts were developed by ultrasonic assisted preparation method to study the photocatalytic activity under visible light irradiation. The samples were characterized by UV-DRS, XRD, FT-IR, XPS, SEM, EDX, TEM, EIS and BET analysis. The photocatalytic activity of NiO/Ag3VO4 nanocomposite for the photodegradation of 4-Nitro Phenol (4-NP) and Rose Bengal (RB) under visible light irradiation was studied and it is observed that the activity has been much higher than that of the pure Ag3VO4. DRS spectrum shows the absorption edge of NiO-Ag3VO4 in visible region of spectrum. The formation of cubic structured NiO and orthorhombic structured Ag3VO4 was confirmed by powder X-ray diffraction analysis. The results of XPS analysis confirmed the coexistence of NiO and Ag3VO4 in the NiO/Ag3VO4 composite. The specific surface area and pore structure of the prepared samples were measured by BET. Enhanced charge separation efficiency was confirmed by electrochemical impedance spectroscopy (EIS) measurements. The kinetics of the NiO/Ag3VO4 nanocomposite was proposed to investigate the intervened effects of NiO to Ag3VO4 on the promotion of photocatalytic property. NiO/Ag3VO4 was found to be stable and reusable without appreciable loss of catalytic activity up to four consecutive cycles. A possible electron-hole transfer mechanism at the NiO/Ag3VO4 interface is proposed. It also showed effective and efficient bactericidal activities against Staphylococcus aureus, Streptococcus, Proteus and Escherichia coli bacteria. Our results provide some new insights on the performance of visible light photocatalysts on environmental remediation.

Determination of thiamethoxam residues in banana stem and fruit through LC-MS/MS.

An analytical method based on liquid chromatography coupled with mass spectroscopy/mass spectroscopy was developed and validated for the determination of thiamethoxam residues in banana fruit and stem tissue samples. In this study, Waters Alliance LC and Acquity TQD were used with an electrospray ionization interface in the positive ion mode. An isocratic flow of 0.5% HCOOH in water and 0.05% HCOOH in CH3CN was used for separation. Thiamethoxam residue was extracted from the samples using CH3CN and a dispersive solid-phase extraction method was used for subsequent cleanup. Linearity studies were conducted between 0.001 and 0.1 µg mL-1 of standard solution with three replicates for each concentration. Satisfactory recoveries (107.21 to 115.16% and 90.94 to 109.22%) and high precision (relative standard deviations of 3.71 to 12.83% and 3.24 to 10.78%) were obtained for the banana stem and banana fruit matrix, respectively. The lower limits of detection and quantification achieved were 0.002 and 0.008 µg g-1 for banana stem and 0.001and 0.005 µg g-1for banana fruit, respectively. The developed method was used to analyze the banana stem and fruit samples collected from thiamethoxam-treated fields and stems from the local market.

Fabrication of g-C3N4/NiO heterostructured nanocomposite modified glassy carbon electrode for quercetin biosensor.

Herein, we report a one-pot synthesis of structurally uniform and electrochemically active graphitic carbon nitride/nickel oxide (g-C3N4/NiO) nanocomposite and an investigation on the electrocatalytic oxidation of quercetin (QR). The synthesized g-C3N4/NiO nanocomposite has uniform surface distribution, which was characterized with scanning electron microscopy (SEM). Moreover, the composition of synthesized g-C3N4/NiO nanocomposite was characterized by UV-vis-spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR spectra), BET, SEM and HRTEM. The g-C3N4/NiO was electrochemically treated in 0.1 MPBS solution through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The peak current response increases linearly with QR concentration from 0.010 µM to 250 µM with a fast response time of less than 2 s and a detection limit of 0.002 µM. To further evaluate the feasibility of using this sensor for real sample analysis, QR content in various real samples including green tea, green apple, honey suckle were determined and satisfactory results were achieved.

Determination of neonicotinoid insecticide residues in sugarcane juice using LCMSMS.

A simple, sensitive and inexpensive LC-MS/MS method was developed and validated for for the simultaneous detection and quantification of (five) neonicotinoid insecticides in sugarcane juice. The juice samples were extracted with acetonitrile and subsequent cleanup was done by dispersive solid-phase extraction (QuEChERS method). The quantification was carried out by liquid chromatography-tandem mass spectrometry with electrospray ionization source (LC-ESI-MS/MS). After the optimization of the extraction parameters, the method was validated by evaluating linearity, limits of detection and quantification, precision (repeatability) and accuracy (recovery). Validation was based on analyses at three fortification levels that showed satisfactory recoveries (62.06-129.93%) and high precision (RSDs between 2.52% and 14.57%). Detection levels for all the five analytes ranged from 0.0007 to 0.002µgg-1 and quantification level ranged from 0.002 to 0.005µgg-1, respectively.

Synthesis and characterization of doxorubicin modified ZnO/PEG nanomaterials and its photodynamic action.

The aim of this study is to investigate a new strategy of combined application of ZnO/PEG nanospheres with anticancer drug of doxorubicin (DOX) in photodynamic therapy (PDT). We were able to fabricate ZnO/PEG nanospheres as the drug carrier of DOX in drug delivery system. The combination of DOX-ZnO/PEG nanocomposites induced the remarkable improvement in the anti-tumor activity, which has been demonstrated by antibacterial activity, drug release and DNA cleavage study. Furthermore, the possible mechanism was explored by optical spectroscopic studies and EPR - spin trapping technique. It was noted that the photodynamic activity of the non-cytotoxic DOX loaded ZnO/PEG nanocomposite could considerably increase cancer cell injury mediated by reactive oxygen species (ROS) under UV irradiation. In our observations demonstrated that ZnO/PEG nanosphere could obviously increase the intracellular concentration of DOX and enhance its potential anti-tumor efficiency, indicating that ZnO/PEG nanosphere could act as an efficient drug delivery carrier importing DOX into target cancer cells. Nearly 91% of loaded drug was released within 26 h of incubation of conjugates in vitro in an acidic environment. It suggests that there is an efficient drug release of DOX from DOX-ZnO/PEG nanocomposite. DOX loaded on ZnO/PEG nanomaterials showed antibacterial activity was more pronounced with Gram-positive than Gram-negative bacteria under visible light. DOX-ZnO/PEG nanocomposites were effective against HeLa cell lines under in vitro condition and photocleavage of DNA. This result indicated that ZnO/PEG nanomaterials can be used as a nanocarrier for drug delivery system for PDT.

Determination of Doxazosin Mesylate in Tablets by RP-HPLC.

A simple, precise and rapid RP-HPLC method was developed for the determination of doxazosin mesylate in pharmaceutical formulations. The method was carried out on a Chromolith RP-C(18) column using a mixture of potassium phosphate buffer and methanol (40:60 v/v) and detection was done at 251 nm. The linearity range was 1-5 µg/ml. The retention time of the drug was 3.8 min. The LOD and LOQ were found to be 0.1 µg/ml and 0.5 µg/ml, respectively.

Simultaneous HPTLC Determination of Rabeprazole and Itopride Hydrochloride From Their Combined Dosage Form.

A simple, precise, sensitive, rapid and reproducible HPTLC method for the simultaneous estimation of the rabeprazole and itopride hydrochloride in tablets was developed and validated. This method involves separation of the components by TLC on precoated silica gel G60F254 plate with solvent system of n-butanol, toluene and ammonia (8.5:0.5:1 v/v/v) and detection was carried out densitometrically using a UV detector at 288 nm in absorbance mode. This system was found to give compact spots for rabeprazole (Rf value of 0.23 0.02) and for itopride hydrochloride (Rf value of 0.75+/-0.02). Linearity was found to be in the range of 40-200 ng/spot and 300-1500 ng/spot for rabeprazole and itopride hydrochloride. The limit of detection and limit of quantification for rabeprazole were 10 and 20 ng/spot and for itopride hydrochloride were 50 and 100 ng/spot, respectively. The method was found to be beneficial for the routine analysis of combined dosage form.