Average Initial Deposits Research Articles

Tandem mass spectrometric analysis of residual persistence, decontamination and dehydration on cyantraniliprole residues in Chilli

The dissipation behavior and persistence of cyantraniliprole residues in chilli and soil were assessed using high performance liquid chromatography and tandem mass spectrometry. Analytical methodology was suitably validated for recovery, precision, accuracy and sensitivity Limit of quantification (LOQ) and limit of detection (LOD) were found to be 0.01 and 0.003 mg kg-1. After two applications of cyantraniliprole @ 60, 75, 120 g a.i ha-1, the average initial deposits were found to be 0.69–0.72, 0.88–0.92, 1.40–1.42 mg kg-1, respectively, years 2021 & 2022. Half-life values (T1/2) for cyantraniliprole in chilli were 3.24, 3.53 and 3.89 days in 2021 and 3.78, 3.62 and 3.79 days in 2022, respectively for 60, 75, 120 g a.i ha-1 dose. Household processing methods were evaluated for decontamination of residues such as tap water wash, luke warm water wash, baking soda, common salt, acetic acid, potassium permanganate and boiling water. Among these methods, washing with boiling water was found to be most effective in reducing cyantraniliprole residues (up to 86%) followed by soaking in potassium permanganate (up to 72.27%) and soaking in baking soda (up to 69.37%). After dehydration of red chilli fruits, highest processing factor was 2.40 and 2.45 after application of cyantraniliprole @ 75 and 120 g a.i ha-1 in the test years.

Dissipation kinetics, risk assessment, and waiting period of spiromesifen on chili fruits using gas chromatography-electron capture detector.

A supervised field trial was designed in Rajasthan Agricultural Research Institute, Durgapura, Jaipur, Rajasthan, to assess the dissipation and persistence of spiromesifen in chili fruits. Spiromesifen (22.9% suspension concentrate) was sprayed two times at an interval of 10 days at the recommended dose (96 g. a.i. ha-1 ) and double the recommended dose (192 g. a.i. ha-1 ) with four replications. Sampling was done according to the planned interval of days after the second spray. Extraction and cleanup were performed using the modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method and the spiromesifen residue was analyzed by GC-electron capture detector and confirmation performed using GC-MS. The average initial deposit of spiromesifen was 1.207 mg kg-1 and 1.948 mg kg-1 at the recommended and double the recommended dose, respectively. The half-life values of spiromesifen ranged between 2.7 and 3.2 days at the recommended and double the recommended dose. The safe waiting period was calculated for the respective doses and it was concluded that an average of 7 days is safe for picking. The FSSAI (Food Safety and Standards Authority of India) have set the maximum residue limit of 0.1 mg kg-1 for spiromesifen in green chili. The theoretical maximum residue contribution value of spiromesifen was lower than the maximum permissible intake at both the applications on the 0th day. Hence, there will be no adverse effects on human health after consumption of green chilies.

Residual Behavior of Tebuconazole and Trifloxystrobin in Okra Fruits and Soil

ABSTRACT A field trial was conducted to study the dissipation of trifloxystrobin and tebuconazole on okra following application of Nativo (tebuconazole 50% + trifloxystrobin 25% WG) at 350 and 700 g ha−1. The estimation of trifloxystrobin and CGA 321113 residues was carried on gas–liquid chromatograph equipped with electron capture detector and that of tebuconazole on gas chromatograph–mass spectrometry. Average initial deposits of tebuconazole in okra were found to be 0.75 and 1.45 mg kg−1, whereas trifloxystrobin was found to be 0.28 and 0.61 mg kg−1 following the application of Nativo at 350 and 700 g ha−1, respectively. Residues of tebuconazole dissipated below limit of quantification of 0.05 mg kg−1 after 7 and 10 days and of trifloxystrobin after 5 days of last application at recommended and double of the recommended dosages, respectively. For risk assessment studies, theoretical maximum residue contributions (TMRC) were calculated and compared with maximum permissible intake (MPI). It was observed that TMRC values were below MPI in zero day samples at both recommended and double of the recommended dosages. Therefore, the waiting period of 1 day should be observed for safe consumption of okra treated with tebuconazole and trifloxystrobin.

Dissipation pattern and dietary risk assessment of some commonly used insecticides on tomato (Solanum lycopersicum L.)

Pesticide residue in food commodities is a serious concern in relation to consumer safety and also the most significant barrier in the trade of food commodities. The dissipation pattern of four insecticides, namely novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin, was evaluated on tomato fruits and cropped soil. The residues were extracted using the QuEChERS analytical method and quantized using a gas chromatograph with electron capture detector, gas chromatograph mass spectrometer, and high-performance liquid chromatography with photo diode array detector. The analytical method was validated using parameters like recovery, linearity, accuracy, matrix effect, and specificity, with limit of detection and limit of quantitation established to be 0.01 and 0.05 mg/kg, respectively, for all the pesticides. The average initial deposits (samples collected after 2 h of application) at the recommended dose of novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin were 0.593, 0.293, 0.227, and 0.431 mg/kg on tomato fruits, respectively, and were below the limit of quantification in soil. The pre-harvest interval of 17, 8, 1, and 13 days was suggested for novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin on tomato, respectively. Risk assessment studies revealed that all pesticides under study are safe and do not pose any threat to humans as theoretical maximum dietary intake is less than the maximum permissible intake and acceptable daily intake.

Dissipation and gas chromatographic method for the determination of profenofos residues in/on green pea and cucumber.

Herein we report a novel, accurate and cost-effective gas chromatography method for the determination of average deposits of profenofos on green pea and cucumber following good agricultural practices. Additionally the risk assessment, dissipation and waiting period for profenofos were determined. The average initial deposits (2h after spraying) of profenofos in/on green pea and cucumber were 3.41 and 3.62 mg kg-1 respectively following two applications at a 10 day interval of profenofos 50EC formulation. Profenofos residues on both of the substrates were below the detection limit of 0.05 mg kg-1 after 20 days at the recommended dosage. For risk assessment studies, the 20th day will be safe for consumers for consumption of green peas. The gas chromatography method was validated according to the SANTE guidelines using the various analytical parameters: linearity, accuracy, detection and quantification limits. The developed method is simple, selective and repeatable and can be extended for profenofos-based standardization of pesticide formulations for green pea/cucumber and their use as pesticides.

Dissipation studies of chlorantraniliprole in maize leaves, grains, baby corn and soil

ABSTRACT The estimation of a residual level of chlorantraniliprole (Coragen 18.5 SC) in maize leaves, corn, and soil was studied using high performance liquid chromatograph (HPLC), after foliar spray at an application rate of 37 and 74 g a.i. ha−1. The average initial deposits of chlorantraniliprole in leaves were recorded as 19.84 and 32.57 mg kg−1 after application at 37 and 74 g a.i. ha−1 dose, respectively. The residues in maize leaves was found to be below the limit of quantification (LOQ) of 0.03 mg kg−1 after 30 days of the application at recommended and double the recommended dosage. On the 25th day, the residues level of chlorantraniliprole was not detected in baby corn samples. At harvest time, its residues level in grains and soil was found to be below the LOQ. The half-life calculated following zero-order, first-order and second-order kinetics was, 0.27 and 0.28 days, 98.80 and 232.98 days and 2.88 and 2.72 days for recommended and double recommended dose of chlorantraniliprole, respectively.

Estimation of indoxacarb and thiamethoxam residues in chilli

ABSTRACT Supervised field trials were conducted for two consecutive years to estimate the dissipation and persistence of indoxacarb and thiamethoxam residues in chilliafter two foliar applications of Indoxacarb 14.5 SC @ 55 and 110 g a.i. ha−1 and seed treatment of Thiamethoxam 30 FS @ 2.1 and 4.2 g a.i. ha−1. The chilli fruit samples that were collected at different time intervals were processed by QuEChERS methodology, and residues of indoxacarb and thiamethoxam were determined by Gas Liquid Chromatography (GLC) and Gas Chromatography-Mass Spectrometry (GC-MS/MS). The average initial deposits of indoxacarb on green chilli fruits were found to be 2.75 and 5.93 mg kg−1 at single dose while 2.56 and 5.68 mg kg−1 at double dose, respectively, in years 2019 and 2020. These residues reached below the limit of quantification (0.01 mg kg−1) after 25 and 35 days, respectively, at both the doses. The mean residues of thiamethoxam in seedlings, green chilli fruits and red chilli fruits were observed to be below its limit of quantification (0.05 mg kg−1) while, in nursery soil, the residues remained detectable till 10 and 15 days after single and double doses. The half-life value of indoxacarb in green chilli was calculated to be 3.46–4.77 and 3.58–3.76 days while in soil, it was calculated to be 3.85 and 4.93 days, respectively, at single and double recommended doses.

Permethrin and Cypermethrin Residues on Beans and Cucumber Plants Grown Under Greenhouse Conditions

A simple, accurate, and cost-effective procedure for separation and quantification of two pyrethroid insecticides residues on bean and cucumber plants was achieved using a Gas Chromatograph (GC) equipped with an electron capture detector (GC-ECD) and GC equipped with a Mass Selective Detector (MSD). Following spraying fruits and leaves were collected to determine insecticides dissipation constants and half-lives (T1/2 values). Residues of the two pyrethroids revealed the presence of permethrin isomers at retention times of 26 and 26.6 min that correspond to the cis and trans-isomers, respectively. The GC also revealed the presence of four cypermethrin isomers at retention times of 30.3, 30.9, 31.3, and 31.5 min. The average initial deposits of permethrin were 2.7 and 0.2 on cucumber leaves and fruits surfaces, respectively. Whereas cypermethrin initial deposits were 5.1 and 2 μg g-1 on cucumber leaves and fruits, respectively indicating greater deposits on leaves than fruits. T1/2 values of permethrin and cypermethrin residues on beans pods (7.2 and 9.5 d, respectively) and cucumber fruits (13 and 3.3 d, respectively) indicated that a waiting period of 10 and 15 d are required for consumption of cucumber fruits and bean pods sprayed with cypermethrin at the recommended spraying dosage to drop the residues to the Maximum Residue Limits.

Dissipation kinetics of fenazaquin residues in okra and soil under subtropical conditions of Punjab, India

ABSTRACT The supervised field trials were conducted to estimate the dissipation pattern of fenazaquin residues on okra and soil following its three applications @ 25, 50 and 125 g a.i. ha−1. The residue analysis was carried out using high-performance liquid chromatography followed by confirmation with liquid chromatography–mass spectrometry. The average initial deposits were estimated to be 1.663, 2.037, 3.117 and 1.611, 2.299, 3.100 mg kg−1 on okra crop during the year 2017–18 and 2018–19, respectively, at three application rates, i.e.25, 50 and 125 g a.i ha−1.The residues declined below the limit of quantification (LOQ) (<0.01 mg kg−1) after 10 days during 2017–18 and on 15th day during 2018–19, following its application @ 25 g a.i. ha−1. However, with the application @ 50 and 125 g a.i. ha−1, the residues were below LOQ on 15th day of sampling during both the years. Considering the LOQ <0.01 mg kg−1, the pre-harvest interval of 15 days is suggested for the safe consumption of okra fruits following its application @ 25 g a.i. ha−1. The residues dissipated with half-life of 1.31, 1.59, 1.86 and 1.62, 1.75, 1.92 days at the three application rates during both the years. None of the residues were found in soil samples collected after 15 days of the last application.

Estimation of diafenthiuron residues in cabbage by hplc and confirmation by lc-ms-ms

Diafenthiuron, 1-tert-butyl-3-(2,6-diisopropyl-4-phenoxyphenyl) thiourea, a broad spectrum insecticide cum acaricide belonging to thiourea group, has been found effective in managing sucking pests and mites. The persistence pattern of its Polo 50% WP on cabbage following three applications at 300 and 600 g a.i. ha⁻¹ at an interval of 10 d, is reported. Residues were estimated by HPLC and confirmed by LC-MS-MS. The average initial deposits were 0.60 and 1.27 mg kg⁻¹ on the cabbage heads following its third application at single and double the recommended dosages, respectively. Half-life periods were found to be 1.88 and 2.15 d at the two application rates, respectively. The residues reduced to below its limit of quantification of 0.05 mg kg⁻¹ after 7 and 10 d, at the single and the double dosages respectively.

Persistence and dissipation kinetics of chlorantraniliprole in okra and soil

Persistence and dissipation pattern of chlorantraniliprole, an anthranilic diamide insecticide, is reported in okra and soil following application at 25 (recommended) and 50 g a.i. ha−1. High performance liquid chromatograph (HPLC) was used to estimate the residues. The average initial deposits of chlorantraniliprole in okra were 0.21 and 0.46 mg kg−1 at 25 and 50 g a.i. ha−1, respectively. At the recommended dose, the initial residues were below the MRL (0.3 mg kg−1) in okra fruits. The residues dissipated to below the limit of quantification (LOQ) of 0.03 mg kg−1 after 7 and 10 d of the application of insecticide at the two doses respectively. The residues in soil were below the LOQ after 15 d of spray at the recommended dosage. The half-lives (t1/2) and waiting periods of chlorantraniliprole in okra were calculated to be 2.27 and 2.45 d and 0 and 1 d, at the recommended and double the recommended dosages respectively.

Persistence, dissipation kinetics, and waiting period of ethion on cucumber by gas chromatography‐electron capture detector

AbstractThis study investigated the persistence, half life, dissipation kinetics, and waiting period of ethion on cucumber by gas chromatography‐electron capture detector. The residue analysis of ethion on cucumber was carried out by spraying ethion 50EC 500 g a.i. ha−1 at fruit developing stage followed by another application at 10‐day interval and residue were estimated by validated a method on gas chromatography. The sample extraction and clean up was done by modified quick, easy, cheap, effective, rugged, and safe method. The average initial deposits of ethion on cucumber fruit were found to be 0.92 mg/kg, by following two applications at 10‐day interval of ethion 50EC at 500 g a.i. ha−1. Residues of ethion reached below limit of detection 0.05 mg/kg after 15 days at recommended dosage. Therefore a waiting period of 15 day is suggested to reduce the risk before consumption of cucumber fruit samples after following Good Agricultural Practices. These results would be helpful for safe use of ethion on cucumber and to prevent any health problem to consumers. Since the developed method is simple, sensitive, selective and repeatable, it can be extended for ethion based standardisation of herbal formulations containing cucumber and its use in pesticide industries.

Residual behaviour of imidacloprid in the country bean growing soil

The assessment of residual behavior of imidacloprid (Admire 20SL) in the soil of country bean agroecosystem and its risk assessment for consumption was studied. QuEChERS method was used for the extraction and clean-up of samples and the residues of imidacloprid was estimated using Gas Chromatography. The dissipation studies in the soil system were carried out by application of imidacloprid at five different dosages i.e. 100, 200, 300, 400, and 500 g a.i. ha-1. Average initial deposits of imidacloprid were found to be 0.99, 1.33, 1.62, 1.83 and 2.20 mg.kg-1. The residues reached below determination limit (BDL) of 0.01 mg kg-1 in 9 days for recommended dose and 12 days for remaining higher dosages. Half-life (T1/2)) of imidacloprid in the soil was observed to be 1.88, 1.74, 1.73, 1.56 and 1.52 days for 100, 200, 300, 400, and 500 g a.i. ha-1, respectively. The chemodynamics study of imidacloprid spray indicated that only 27.20 -28.40% sprays were deposited to the target site (plant canopy) and 71.60-72.80% were lost to non-target site such as soil and air. The drift of imidacloprid to soil (39.47-40.20%) was higher than the air (32.13-32.60%). Based on degradation pattern and maximum, the recommended preharvest interval (PHI) might be eight 9 days and a waiting period of two days might be suggested for reapplication of the imidacloprid in country bean agroecosystem.&#x0D; Bangladesh J. Agril. Res. 44(1): 89-101, March 2019

Dissipation and Residual Bioefficacy of Chlorantraniliprole in Tomato and Brinjal Fruits

Dissipation of chlorantraniliprole residues on tomato and brinjal fruits and cropped soil is reported by high performance liquid chromatography and confirmed by liquid chromatograph-mass spectrometer. The average initial deposits of chlorantraniliprole (18.5 SC) were 0.03 and 0.04 mg kg−1 in tomato which dissipated to below the maximum residue limit(0.03 mg kg−1) after 1 and 3 d after application of chlorantraniliprole @ 30 and 60 g a.i. ha−1 respectively. In case of brinjal crop, the initial deposits were 0.19 and 0.40 mg kg−1 after its application @ 40 and 80 g a.i. ha−1 respectively, which dissipated to below the limit of quantification (0.03 mg kg−1) after 7 d of spray. At 30 and 40 g a.i. ha−1 also, it proved effective in managing the damage caused by fruit borers in tomato and brinjal crops respectively.

Persistence and effect of decontamination processes on reduction of cypermethrin in okra (Abelmoschus esculentus) fruits

Persistence of cypermethrin and decontamination processes on reduction of cypermethrin residues was studied in okra (Abelmoschus esculentus L.) fruits following foliar application of formulation at dose of 50 and 100 g a. i./ha in a field at the Research field of CCS HAU, Hisar, India. Samples of okra fruits were collected periodically and residues were estimated by GC-ECD and confirmed by GC-MS. The average initial deposits of cypermethrin were 0.119 and 0.272 mg/kg in the okra fruits at single and double dose, respectively, one hour after the application. Residues of cypermethrin reached equal to below determination level (0.01mg/kg) on 10th in single dose and after 15 days at double dose. Half-life periods for cypermethrin were observed to be 2.74 days and 3.31 days at single and double dose, respectively following first order kinetics. Residues were below maximum residue limit (MRL) value of 0.2 mg/kg on 0 day in single dose and 1 day in double dose. Safe waiting period of 2 days has been suggested for safety sake. Decontamination processes were found very effective in reducing the residues of cypermethrin in okra fruits. Washing reduced the residues in the range of 39-41 %, whereas washing followed by boiling reduced 71 to 79% residues. In soil, residues of cypermethrin reached below detectable level of 0.005 mg/kg after 3rd and 5th days of application at single and double dose, respectively.

Residue behaviour of profenofos and triazophos in okra (Abelmoschus esculentus) and their decontamination using culinary processes

The persistence pattern and risk assessment of profenofos and triazophos in okra (Abelmoschus esculentus (L.) Moench) and cropped soil were studied in the present study. The insecticides were applied twice at 10 days interval @ 500 and 1000 g a.i./ha. Residues were quantified at 0, 1, 3, 5, 7, 10, 15 and 20 days of second application using GC equipped with Flame Photometric Detector (FPD). The average initial deposits of triazophos (1.838 mg/kg) in okra fruits were higher than profenofos (1.418 mg/kg) at the recommended application rates. Both the insecticides followed a first order kinetics with half-lives of 1.6 and 1.4 days, respectively on okra fruits. The initial deposits of 0.483 and 0.500 mg/kg, for respective insecticides, disappeared to BDL on 5th and 7th day in okra cropped soil. Microwave oven cooking proved more promising than other household processing in dislodging the residues of test insecticides from okra fruits. On the basis of this study, waiting periods of 7.6 and 7.4 days were suggested for consumption of okra sprayed with profenofos and triazophos, respectively.

Dissipation pattern and risk assessment studies of triazophos residues on capsicum (Capsicum annuum L.) using GLC-FPD and GC-MS.

The present study was carried out to observe the dissipation pattern of triazophos on capsicum and risk assessment of its residues on human beings and to suggest a waiting period for the safety of consumers. Following two applications of triazophos (Truzo 40 EC) at 500 and 1000g a.i. ha(-1), the average initial deposits were found to be 3.61 and 6.26mgkg(-1), respectively. These residues dissipated below the limit of quantification (LOQ) of 0.05mgkg(-1) in 10 and 15days at the recommended and double the recommended dosages, respectively. The calculated values of half-life were 2.31 and 2.14days at recommended and double the recommended dosages, respectively. Theoretical maximum residue contribution (TMRC) values were found to be 28.8 and 41.6μg person(-1)day(-1) at 500 and 1000g a.i. ha(-1), respectively, and found to be below the maximum permissible intake on capsicum fruit on the 7th day. Therefore, a waiting period of 7days is suggested for consumption of capsicum sprayed with triazophos at the recommended dosages.

Bioefficacy evaluation and dissipation pattern of nanoformulation versus commercial formulation of pyridalyl in tomato (Solanum lycopersicum).

A study was undertaken to evaluate the decline of the residues of pyridalyl in tomatoes grown in two different cultivation systems: open field (conventional cultivation) and net house (pot experiment). Field experiment was conducted with commercial (10 EC) and nanoformulation of pyridalyl on tomato crop. Tomato plants were subjected to pesticide spray, when fruits were close to ripeness. Fruit samples were taken periodically and cleaned up using QuEChERS methodology, and the residue of pyridalyl was analyzed by ultrahigh-performance liquid chromatography (UHPLC). It dissipated in tomato fruit following the first-order kinetics. In field, average initial deposit of pyridalyl in tomato was observed to be 0.222 and 0.371μgg(-1) at recommended and double the recommended application rate, respectively, using nanoformulation while it was 0.223 and 0.393μgg(-1) on using commercial formulation, respectively. The half-life (t1/2) value of nanopyridalyl in tomato fruit was 2.8 and 3.2days while for commercial formulation, it was 2.5 and 2.6days for recommended and double the recommended dose, respectively. In India, maximum residue limit (MRL) on tomato has not been fixed for pyridalyl but its residues were always below European MRLs (5μgg(-1)) on tomato at both application rates. The results of terminal residue showed that pyridalyl residues were below the available MRL. Low residues in tomatoes suggested that this pesticide is safe to use under the recommended dosage. No statistical differences were observed between the cultivation systems in relation to the residue levels of pyridalyl.

Degradation of chlorpyrifos residues in apple under temperate conditions of Kashmir Valley.

The present studies were carried out to observe the dissipation pattern of chlorpyrifos on apple in Kashmir Valley. Persistence of chlorpyrifos in apple was studied following two applications rates of chlorpyrifos (Dursban 20 EC) at 200g a.i. ha(-1) (single dose T 1) and 400g a.i. ha(-1) (double dose T 2). The average initial deposit of chlorpyrifos was found to be 1.61 and 1.98μgg(-1) for T 1 and T 2 application rates respectively on apple. The residues dissipated to 0.09 and 0.06μgg(-1) after 15- and 30-day post treatment with half-life periods of 3.34 and 5.47days in T 1 and T 2 application rates, respectively. The residues of chlorpyrifos dissipated to below limit of quantification (LOQ) of 0.04μgg(-1) after 30day at T 1 application rate. A waiting period of 6days must be observed for chlorpyrifos on apple at recommended application rate for the safety of consumers. Theoretical maximum residue contribution (TMRC) values were found to be far less than maximum permissible intake (MPI) at 0day in both the dosages suggesting chlorpyrifos on apple in Kashmir is unlikely to cause health risks.

Fate of thiodicarb and its metabolite methomyl in sandy loam soil under laboratory conditions.

Fate of thiodicarb and its major metabolite in sandy loam soil were studied by applying thiodicarb (Larvin 75 WP) at 500 and 1000ga. i. ha(-1) under laboratory conditions. Samples drawn periodically were analysed on GC-FTD equipped with capillary column. The average initial deposits of total thiodicarb (thiodicarb and methomyl) were 0.025 and 0.035mgkg(-1) at single and double dosages, respectively. Residues of thiodicarb reached below the determination level (BDL) of 0.005mgkg(-1) after 15days. Half-life periods for total thiodicarb were calculated to be 5.90 and 8.29days at two doses, respectively, following first-order kinetics.