Analytical Study for Chlorpyrifos Breakdown Derivatives Qualication After Silver Vanadate (Agvo3) Nanoparticles Fragmentation Reaction

The use of pesticides in agriculture has become one of the basic necessities to meet the world's food requirements as a result of the continuous population increase. But sometimes the use of some of these pesticides in large quantities and in high concentrations poses a great danger to the environment and then to humans. Through weather factors, pesticides are transferred to the water and then harm aquatic organisms, which leads to a direct impact and harm to the sh wealth. Monitoring these compounds in the environment requires a large cost of time and money to ensure food safety. Therefore, a new method was used in this study in an attempt to get rid of these compounds in water. The silver vanadate nanoparticles (AgVO3) were synthesized using a novel method in an attempt to eliminate different groups of pesticides that had been detected in Egyptian agricultural crops and water. The effect of 0.1 g of AgVO3 nanoparticles were found on three compounds: chlorpyrifos, dimethoate and malathion. Where a concentration of these compounds, which is 0.5 mg / kg, was used and it was estimated using Exion HPLC coupled with Sciex Qtrap API 6500 + LC-MS/MS System. After 15 minutes of treatment with 0.1 g of AgVO3 nanoparticles, these compounds were undetectable on the device's chromatogram, which is regarded a short period in Affecting these compounds and changing their nature in an attempt to get rid of them. Determination of chlorpyrifos breakdown products by using mass scan of Qtrap API 6500 + LC-MS/MS System and Thermo Scientic Q Exactive Focus Orbitrap LC-MS/MS System was investigated. Supported AgVO3 NPs, according to the study, could be used in long-term environmental remediation because they can be used in aqueous solutions at room temperature without the need for additional stimulus such as UV light.


Introduction
The use of pesticides in modern agriculture has become one of the most important necessities to meet the needs of society for food as a result of the continuous increase in the number of the population, and thus millions of tons of pesticides are used annually for this purpose (Rani 2012). Pesticides are among the most widely used chemicals. Despite the importance of using pesticides, they are considered one of the most harmful substances that affect humans, animals, and surface water in particular (McKnight et al. 2015). As a result of applying pesticides in high quantities in the environment, then they may affect surface water and through water storms may lead to a high spread of pollution, which affects aquatic ecosystem (Poulier et al. 2014). Organophosphates are one of pesticide group used to protect plant and increase crop productivity by killing pests and insects. Chlorpyrifos is one of the most popular organophosphate pesticides widely used for controlling pests and diseases for various crops due to its accessibility (Muhamad 2015). Chlorpyrifos (C9H11Cl3NO3PS) O,O-Diethyl O-3,5,6-tri chloro pyridinyl phosphorothioate is one of an organophosphate pesticide used to kill a number of pests including insects and worms. It is used on crops, animals, and buildings (Rathod et al. 2017). In the United States,  (Khan et al. 2018). Ag and Au NPs were used in both approved and unsupported types at room temperature, chlorpyrifos (CP), an organophosphorothioate pesticide, decomposes into 3,5,6-trichloro-2-pyridinol (TCP) and diethyl thiophosphate over. Absorption spectroscopy and electrospray ionisation mass spectrometry were used to identify the degradation products (ESI MS) (Bootharaju et al. 2012). The method presented in this study describes the synthesizing silver vanadate nanoparticles and then using it in degradation of some pesticides. The determination of these compounds were estimated using electrospray positive ionisation (ESI+) by Exion HPLC coupled with Sciex Qtrap API 6500 + LC-MS/MS System. In this study, using mass scan of Qtrap API 6500 + LC-MS/MS System and Thermo Scienti c Q Exactive Focus Orbitrap LC-MS/MS System to determine chlorpyrifos breakdown products. The method used before determination is simple and take a short time to reach to these results by using 0.1 g of silver vanadate nanoparticles.
The column temperature was 40°C and the injection volume was 2 µL. The pesticides are separated using Gradient mixing programme of 10% 50 mM ammonium acetate in deionised water, with 0.1% formic acid as eluent A and methanol as eluent B at 300 µL/min ow rate starting by A bottle 60% for 1 min, changed continuously till 11.5 min to be 10% for 0.5 min, changed progressively till 12 min to be 0% for 2 min and returned to 60% from A in min 14 for 2 min to be 16 min complete run time for every one of the 25 pesticides yet for one pesticide the ow rate starting by A bottle 20%, changed steadily till 3 min to be 20% for 0.5 min and returned to 20% from A in min 3.5 for 1.5 min to be 5 min all out run time. The MS/MS investigation was nished by electrospray ionization in the positive ion mode with multiple reactions monitoring (MRM) mode. The following source and gas parameters were applied: temperature, 400°C; and ion spray voltage, 5500 V.
(6) Ammonia solution (33%) was purchased from Riedel-de Häen (Seelze, Germany). The procedure involves 0.01 mole of ammonium vanadate was dissolved in 20 ml of deionized water and 0.01 mole of silver nitrate was dissolved in 20 ml of deionized water. The silver nitrate solution was added gradually to the ammonium vanadate solution with ultrasonic stirring at room temperature. The PH of colored suspension was adjusted to near 7 using ammonia solution and ultrasonic stirring continued to 3 hour. The obtained suspension was then transferred into Te on-lined vessel and placed in a microwave oven operating at 2.5 GHz and maximum power of 650W at 160°C for 2 hour. The resulting precipitate was ltered and washed several times with deionized water and ethanol using centrifuge for 5 minute at 13000 rpm at each time. After washing, the precipitate was dried at 80°C for 24 hour. At long last the subsequent powder was granulated well to utilize it.

Degradation of pesticides using AgVO3 nanoparticles
The procedure involves 0.1 g of AgVO3 nanoparticles were added to 100 ml of mixture of pesticides 0.5 µg/mL dissolved in in methanol/water (1:1 v/v) using a magnetic stirring to reach equilibrium. AT chosen time intervals, sample aliquots were collected, centrifuged for 5 min at 4000 rpm (3430 rcf) and ltered using syringe lters (0.45 µm) and then transferred to Polypropylene (PP) vial. Finally, the ltrates were further analyzed by LC-MS/MS. The previous steps were repeated again with each pesticide that affected individually. This experiment was conducted repeated several times in dark and visible light using UV lamp at 365 nm and without it at room temperature.

Result And Discussion
A chemical remediation study was evaluated to reducing chlorpyrifos risk from irrigation water. Some chemicals used as catalyst were prepared in Nano-particle phase and were tested in vitro to check their ability to cracking out tested pesticide. An analytical study was used to evaluate catalysts e ciency and the environmental fats for chlorpyrifos using liquid chromatography tandem mass spectrometry. In previews studies the use of gas chromatography coupled with single mass were used to checks compounds with and without a chemical fragmentation test, Also infra-red and NMR determination were used to support compound fat structures. In this investigation a tandem mass was used for the determination of chlorpyrifos breakdown products by using mass scan before multiple reactions monitoring mechanism as a nger prints for the chemical reaction products and also to have relationship between the main compound and its founded products.
Twenty ve pesticides were tested by silver vanadate nanoparticles in visible light at room temperature for 24 hours, only 3 pesticides (chlorpyrifos, dimethoat, malation) were affected till be displayed from solution test, Its clearly they relationships to each other as a organophosphate classi cation which led us to physicochemical theory about the reaction of silver vanadate nanoparticle to breakdown persisted pesticides in environment specially in irrigation water. Table 1 showed dramatically dissipation in 15 min for chlorpyrifos and dimethoat when malation was more resist for more 30 min.
An analytical study was done to investigate chlorpyrifos breakdown fragments using tandem mass spectrometry (Q trap) and hybrid orbitap technique for mass scanning and exact mass determination, Chlorpyrifos and its breakdown derivatives were scanned and determined as a way to investigates bonds breaking pathway. Figure 1 showed the mass scan of chlorpyrifos by rst mass lter including the isotopic distribution of compound due to the present of 3 chlorine atoms, After scanning 350 Dalton was used as mass separation for parent chlorpyrifos in Q1 before special fragmentation in collision cell for two fragments (274 and 198), then Q3 was used as linear ion trap for ltering each fragment before second fragmentation and scanning to found up third mass part from analyte (MS/MS/MS). Figures 2 and 3 showed two different fragments comes from tow fragments from chlorpyrifos (350,274,144 and 350,198,107) as a triple mass nger print for tested analyte. The present of 144 Dalton fragment from 198 parent ion was due to the loss of H2o + Cl when the other fragments 107 was due CO2 + Cl + HCN losses [24]. From the other hand, multiple reactions monitoring mechanism was used to determines all founded compounds in the solution after one day from chlorpyrifos silver vanadate nanoparticles reaction. Figure 4 showed the full scan results found in solution before optimizing best energy and mass unit voltage to found up fragments for these compounds derivatives. Figures 5 and 6 showed the products of two chosen breakdown fragment, the rst one was 174 which broken to 5 detected fragment under instrumental fragmentation and the other was 198 gives 2 fragments one of them was found as third products to main chlorpyrifos, this result led us to similar found in between chemical and instrumental degradation. The present of 198, 199.8 and 202 masses was due to 35Cl3, 35Cl2 37Cl, and 35Cl 37Cl2 isotopomers of TCP (3,5,6-trichloro-2-pyridinol) respectively.
Mass determination with high resolution was studied using hybrid orbitrap mass spectrometry. A high accuracy scan ranged between 85 to 355 Dalton was done for tested solution after Nano reaction as shown in Fig. 7; instrumental method was adjusted for both scanning and special fragmentation for any founded masses between target ranges. Four masses were found in con rming with previews test (Qtrap-6500+): 283.27, 274.27, 197.92 and 169.06.
As showed in Figs. (8-12) the fragments ions with high abundance produced by founded masses after Nano reaction were found 113, 106.945, 108.9423, 209.1536 and 96.0704 respectively which were supported by the triple quadrupole mass instrument and led us to have good idea about the breakdown path way of chlorpyrifos pesticide after remediation reaction with Nano silver vanadate.
This data was in agreement with that found before, the products produced by silver nitrate nanoparticles reaction in 48 hours led to protonated TCP 198 Dalton which produced 144 and 107 Dalton fragments when using 3200 QTrap MS/MS instrument (Bootharaju et al. 2012). Also an accurate mass of 197.9235 was found when scanning chlorpyrifos after Fe oxidation using Triple TOF 5600 mass spectrometry instrument (Liu et al. 2019). From the other hand, the present of 107 as a fragment product from both parents 298 and 274 can explain a possible structure of 274 which was supported in the shown spectrum of TOF triple mass for chlorpyrifos fragmentation (Liu et al. 2019). The use of silver/copper nanoparticles as a catalysts for chlorpyrifos degradation led to TCP and DETP (Diethyl thiophosphate) (Rosbero et al. 2017).
Possible structures for chorpyrifos breakdowns were showed in Figs. (8-12) of orbitrap MS2 scanning and fragmentation can explained the possible pathway of chlorpyrifos when using Nano-silver vanadate in aqueous solution as in vitro examination for this pesticide remediation.
Possible structures for chlorpyrifos breakdowns were showed in Fig. 13 and supported by all previews data that the fragmentations 282 and 198 could be found due to the loss of 2 chlorine atoms in a substitution reaction in chlorpyrifos to get 282 mass and by breaking the single bond between oxygen and phosphorus to get 198 mass, this theory can be supported by the isotopic distribution showed in this scan Fig. 13 and also can explained the possible pathway of chloropyrifos when using silver vanadate nanoparticles in aqueous solution as in vitro examination for this pesticide remediation.

Conclusion
The present study used a mass scan of the Qtrap API 6500 + LC-MS/MS System and the Thermo Scienti c Q Exactive Focus Orbitrap LC-MS/MS System to establish a rapid and simple method for determining chlorpyrifos breakdown products after reaction with synthesized silver vanadate nanoparticles (AgVO3). The addition of 0.1 g of silver vanadate nanoparticles (AgVO3) was enough to decompose 0.5 mg/kg of chlorpyrifos, dimethoate and malathion in 100 ml water/ methanol (1:1 v/v) and breakdown to their products at room temperature in 15 minutes, which was regarded a short period.
The addition of 0.1 g of silver vanadate nanoparticles (AgVO3) were added to different ranges of concentrations of these chemicals up to 5 mg/kg and gave the same results. These chemicals were identi ed using an electrospray positive ionisation (ESI+) by an Exion HPLC paired with a Sciex Qtrap API 6500 + LC-MS/MS system. To determine chlorpyrifos breakdown products, the mass scans of the Qtrap API 6500 + LC-MS/MS System and the Thermo Scienti c Q Exactive Focus Orbitrap LC-MS/MS System were employed. The use of a UV lamp, as well as conducting the experiment in the dark, yielded negative ndings. When the experiment was carried out in visible light at room temperature, good ndings were obtained. The breakdown products of chlorpyrifos were obtained in a short amount of time, demonstrating the clear action of silver vanadate nanoparticles. The synthesized silver vanadate nanoparticles (AgVO3) may be used as a packed lter to avoid its spread in water and it may be increased its e ciency by adding an element as a Nano composite material. The fact that degradation occurs at room temperature and on supported NPs, on the other hand, is signi cant since it allows such materials to be used for water ltration. In such cases, a post degradation phase using adsorbents such as activated carbon is required to remove the degradation products.  Chlorpyrifos triple followed mass lters using Q trap mechanism (350,198,107).

Figure 3
Chlorpyrifos triple followed mass lters using Q trap mechanism (350,274,144).      Total ions chromatogram for all residues after nanoparticles reaction using Orbitrap scanning mode.  Big abundance ion after fragmentation of 197.9 Da ion using Orbitap MS2.

Figure 10
Big abundance ion after fragmentation of 199.9 Da ion using Orbitap MS2.

Figure 11
Big abundance and parent ions after fragmentation of 174 Da ion using Orbitap san and MS2.  Q1 scanning from the most high abundance fragments produced after reaction.