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This work presents a simple procedure for pre-column derivatization of glyphosate and aminomethylphosphonic acid (AMPA) and their determination by high-performance liquid chromatography (HPLC). Derivatization was achieved by mixing a solution of 0.02 M FMOC-Cl, 0.05 M borate buffer and glyphosate or AMPA, then shaken for 1 hour, later washed with d...
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... of GLY or AMPA occurs in alkaline condition and is based on the reaction between FMOC-Cl and amino functional group of GLY or AMPA thus, is achieved through a substitution of H atom from GLY or AMPA with aromatic ring of FMOC-Cl yielding FMOC-GLY or FMOC-AMPA and HCl [24] as shown in Fig 1. These resultant derivatives are compounds with both polar and non-polar properties. ...
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In this work, the direct determination methodology of glyphosate and aminomethylphosphonic acid (AMPA) by high performance liquid chromatography (HPLC) using inductively coupled plasma with triple quadrupole mass spectrometer (ICP-MS/MS) was compared with the conventional method using diode array detector (HPLC-DAD). Both methods were selective, bu...
Citations
... When liquid chromatography with derivatization is applied, the prevalent derivatizing agent is FMOC-Cl (9-fluorenylmethyl chloroformate). FMOC-Cl reacts with glyphosate and AMPA to give the corresponding derivatives [33][34][35][36][37][38][39][40][41][42]. The determination of glyphosate by liquid chromatography is also possible without derivatization. ...
... Choosing an analytical method depends on the objective to be achieved. For compliance control purposes, an instrument with sensitivity of at least 1 mg kg −1 would be suitable for 91% of the established MRLs listed in Table 2. So, the much simpler and historically widely used HPLC-fluorimetry (HPLC-FLD) [98][99][100][101] or HPLC-UV [39,42,85] would be still suitable for the aim, in fact the limit of quantitation of these techniques is about 0.5 mg kg −1 [98]. Similar considerations apply to gas chromatography with nitrogen phosphorus (NPD) or a flame photometric detector (FPD), which are less specific detectors than mass spectrometers but of higher affordability and of good sensitivity [51,102]. ...
The European Union’s recent decision to renew the authorization for the use of glyphosate until 15 December 2033 has stimulated scientific discussion all around the world regarding its toxicity or otherwise for humans. Glyphosate is a chemical of which millions of tons have been used in the last 50 years worldwide to dry out weeds in cultivated fields and greenhouses and on roadsides. Concern has been raised in many areas about its possible presence in the food chain and its consequent adverse effects on health. Both aspects that argue in favor of toxicity and those that instead may indicate limited toxicity of glyphosate are discussed here. The widespread debate that has been generated requires further investigations and field measurements to understand glyphosate’s fate once dispersed in the environment and its concentration in the food chain. Hence, there is a need for validated analytical methods that are available to analysts in the field. In the present review, methods for the analytical determination of glyphosate and its main metabolite, AMPA, are discussed, with a specific focus on chromatographic techniques applied to cereal products. The experimental procedures are explained in detail, including the cleanup, derivatization, and instrumental conditions, to give the laboratories involved enough information to proceed with the implementation of this line of analysis. The prevalent chromatographic methods used are LC-MS/MS, GC-MS/SIM, and GC-MS/MS, but sufficient indications are also given to those laboratories that wish to use the better performing high-resolution MS or the simpler HPLC-FLD, HPLC-UV, GC-NPD, and GC-FPD techniques for screening purposes. The concentrations of glyphosate from the literature measured in wheat, corn, barley, rye, oats, soybean, and cereal-based foods are reported, together with its regulatory status in various parts of the world and its accumulation mechanism. As for its accumulation in cereals, the available data show that glyphosate tends to accumulate more in wholemeal flours than in refined ones, that its concentration in the product strictly depends on the treatment period (the closer it is to the time of harvesting, the higher the concentration), and that in cold climates, the herbicide tends to persist in the soil for a long time.
... When Liquid Chromatography with derivatization is used the prevalent method is with FMOC-Cl (9fluorenylmethyl chloroformate). FMOC-Cl reacts with glyphosate and AMPA to give the corresponding derivatives [33][34][35][36][37][38][39][40][41][42]. The determination of glyphosate by liquid chromatography is also possible without derivatization: in such a case Ion Exchange Liquid Chromatography is used. ...
... Other detectors more affordable than mass spectrometry in terms of costs, maintenance, and learning, also 7 exist. We are talking about the much simpler and historically widely used HPLC-Fluorimetry (HPLC-FLD) [98][99][100][101] or HPLC-UV [39,42,87] which have less sensitivity and specificity than mass spectrometry but would still be suitable for checking the compliance of many of the cereal products listed in Table 2. The same apply to gas chromatography with nitrogen phosphorus detection (NPD) or with flame photometric detection (FPD) which are more affordable than gas chromatographymass spectrometry but with less sensitivity and specificity [51,102]. ...
The European Union's recent decision to renew the authorization for the use of glyphosate until 15 December 2033 stimulates the scientific discussion all around the world regarding its toxicity or otherwise for humans. Glyphosate is a chemical used by millions of tons in the last 50 years worldwide to drying weeds in cultivated fields, greenhouses, roadsides. Concern has been raised in many quarters about the possible presence in the food chain and the consequent adverse effects on health: both aspects that argue in favor of toxicity and those that instead may indicate limited toxicity of glyphosate are here discussed. The great debate that has been generated requires further investigations and field measurements to understand its fate once dispersed in the environment and its concentration in the food chain. Hence the need for validated analytical methods that are available to analysts in the field. In the present review, methods for the analytical determination of glyphosate and its main metabolite, AMPA, are discussed, with a specific focus on chromatographic techniques applied to cereal products. The experimental procedures are explained in any detail, including cleanup, derivatization, and instrumental conditions to give the laboratories involved enough information to proceed with the implementation of this line of analysis. The prevalent chromatographic methods used are LC-MS/MS, GC-MS/SIM, and GC-MS/MS but sufficient indications are also given to those laboratories that wish to use the simpler HPLC-FLD, HPLC-UV, GC-NPD or GC-FPD techniques for screening purposes. Concentrations from literature measured in wheat, corn, barley, rye, oats, soybean, and cereal-based foods are reported together with the regulatory status in various parts of the world and the accumulation mechanism. As for the accumulation in cereals, available data show that glyphosate tends to accumulate more in wholemeal flours than in refined ones, that its concentration in the product strictly depends on the treatment period (the closer it is to the time of harvesting, the higher the concentration) and that in cold climates the herbicide tends to persist in the soil for a long time.
... After digestion of plant samples (Estefan et al. 2013), determination of N, K, and P contents in samples was done through the Kjeldahl apparatus, flame photometer, and spectrophotometer, by following the standard procedures (Olsen et al. 1954;Bremner and Mulvany 1982;Baghel 2012). The glyphosate analysis was done by following the procedure of Garba et al. (2018). Briefly, 10 g of soil spiked with glyphosate was added into 50-mL centrifuge tubes and then 20 mL 0.01 M KH 2 PO 4 was poured into it, and the mixture was shaken for 2 h on a rotary shaker. ...
... The mixture was kept on a shaker for 60 min at 180 rpm, after which 2 mL diethyl ether was added to each tube and swirled for another 2 min to remove unreacted FMOC-Cl. Thereafter, the organic layer was discarded, and the aqueous solution was transferred to GC vials for further analysis (Garba et al. 2018). ...
Here, a pot experiment was carried out to assess the effectiveness of co-application of a microbial consortium and L-tryptophan (L-TRP) on bioremediation of glyphosate and growth of mungbean (Vigna radiata L.) in glyphosate-contaminated soil. Mungbean seeds (untreated or treated with L-TRP) were sown in the soil that was spiked with glyphosate (600 mg kg−1) and the microbial consortium (comprising of Achromobacter xylosoxidans strain MH-13, Stenotrophomonas sp. strain MH-18, Alcaligenes faecalis strain MH-22 and Stenotrophomonas rhizophila strain MH-24) was applied to the selected pots. Results depicted that the microbial consortium and L-TRP considerably ameliorated the physiology, nutrient uptake, growth, and
yield attributes of mungbean plants, and their co-application signifcantly increased agronomic (57–70%), nutrient uptake (19–38%), and physiological (24–78%) and yield (37–72%) attributes of mungbean over un-amended contaminated controls.
Furthermore, successful removal of glyphosate was observed by the sole addition of microbial consortium (73%) and L-TRP (49%), and this removal of glyphosate was further increased by co-addition of microbial consortium and L-TRP (61% and 82% in unplanted and planted treatments, respectively) over respective controls. Findings from this study imply that the co-addition of a microbial consortium with L-TRP could be a sustainable strategy for improving the glyphosate remediation and productivity of mungbean in glyphosate-contaminated soil.
... Data were obtained and investigated using clarity chromatography computer software. For quantification, a calibration curve was constructed using the known quantities of glyphosate standards [47]. Glyphosate biodegradation was checked after 7-, 14-, and 28-day intervals, and the degraded concentration was calculated using Equation (1). ...
Glyphosate is a non-selective herbicide that is used to control perennial weeds in agriculture. However, its vast application may result in glyphosate residues in food chain. Due to its toxicity to non-target organisms, glyphosate contaminated soils needed to be remediated, and bioremediation is a conventional remedial method. The success of this depends on isolation of bacteria with the ability to degrade glyphosate. The goal of this study iswas to isolate glyphosate-degrading bacteria from the rhizosphere of maize and wheat with repeated application history of glyphosate for 5-10 years and test their roles in promoting the growth of maize (Zea mays) and glyphosate degradation in vitro. Eleven isolated bacteria were isolated,inoculated and their role in plants growth was compared at different levels (100 and 200 mg/kg) of glyphosate. The results revealed that E. ludwigii improved highest shoot length 26% and root length 34% as compared to control at 100 mg/kg. Relative water contents in leaves significantly improved 58% by P. aeruginosa at 100 mg/kg. Maximum electrolyte leakage form leaves significantly reduced 73% by E. ludwigii at 100 mg/kg as compared to control (uninoculated). While highestHigh Pressure Liquid Chromatography instrument was used to assess the glyphosate concentrations. Highest degradation of glyphosate was observed in treatments inoculated with E. ludwigii (99 and 40%), P. aeruginosa (95 and 39%), K. variicola, (91 and 38%) E. cloacae (92 and 38%) and S. liquefaciens (87 and 36%) respectively at 100 and 200 31 mg/kg within 28 days. These five strains demonstrated a great potential for degrading glyphosate and promoting the growth of maize in vitro, and they will be further exploited for biodegradation of glyphosate and growth promotion of broader crop species in situ in the near future.
... AMpA. The analysis of GLY and AMPA in the solution was performed according to a method developed earlier 29 . Briefly, 1 mL of either standard solution or extract was mixed with 1 mL of 0.02 M FMOC-Cl solution in the presence of 2 mL 0.05 M borate buffer. ...
Glyphosate (GLY) is a major herbicide used throughout the world, and its continuous application has become an environmental issue. Adsorption is an important mechanism for removing organic contaminant in water. The present study characterized cow dung (CD) and rice husk ash (RHA), and determined the adsorption-desorption of GLY and its metabolite, aminomethylphoshonic acid (AMPA), on to them. The results revealed that both CD and RHA were alkaline and had no or low content of arsenic, cadmium, chromium and lead. The CD had lower surface area (13.104 mg2g−1) than RHA (21.500 m2g−1). The CD contained amines, phenol, ethers and carboxylic functional groups, while in addition to carboxylic and ether, RHA contains siloxane. Both CD and RHA had high affinities for GLY and AMPA. The Freundlich sorption coefficient (Kf) on AMPA were 2.915 and 2.660 for CD and RHA, respectively, while the values on GLY were 1.168 and 1.166 (mg g−1) for CD and RHA, respectively. Desorption of GLY only occurred at lower concentrations, while no desorption of AMPA was recorded, indicating their strong adsorption on CD and RHA. Considering their availabilities and affordable prices, both CD and RHA can be recommended as economical adsorbent for the removal of GLY and AMPA.
Introduction. Traditionally, the hygienic assessment of working conditions when using glyphosate preparations, an extremely popular herbicide in the world, is based on the use of thin layer chromatography. In this paper, alternative approaches are considered. On the basis of experimental data, the conditions for the analysis of glyphosate content in air by high performance liquid chromatography were optimized. Material and methods. All work with glyphosate solutions was carried out in polypropylene vessels. Sampling from the air medium was carried out on a medium filtration filter (“blue ribbon”). Subsequent extraction was carried out with water. The measurements were performed by high performance liquid chromatography with a fluorimetric detector at an excitation wavelength of 270 nm and an emission wavelength of 313 nm. To transfer glyphosate to a molecule with fluorimetric properties after derivatization of glyphosate in an alkaline medium using 9-fluorenylmethyl chloroformate by heating and washing off the excess of the reagent with toluene. A C18 reverse phase column was used; ammonium acetate with the addition of acetic acid and acetonitrile were used as eluents. Results. Approbation of the developed technique was carried out on real samples taken during ground treatment of fallow fields and lands of industrial territories with glyphosate preparations. The detected levels of glyphosate did not exceed the lower limit of quantitative determination: 0.5 mg/m3 in the air of the working area and 0.025 mg/m3 in the atmospheric air (with maximum allowable concentrations of 1.0 and 0.1 mg/m3, respectively). Limitations. The study considers a limited number of chromatographic columns. The study is performed on 25 model samples of the air of the working area and atmospheric air. Conclusion. Based on the results of the work performed, methodological instructions “Measurement of glyphosate concentrations in the air by high-performance liquid chromatography” were formed and sent for metrological certification in the approved manner.
The intensive use and accumulation of glyphosate cause many environmental and ecological problems. There is an urgent need for an effective detection method for glyphosate. Many studies in the literature determine glyphosate by an enzyme-based method, requiring appropriate temperature, pH, substrate and ionic strength. In this study, we presented a simple enzyme-free reaction system. Two new simple Schiff base derivatives, 4-(((3-chloropyridin-4-yl)imino)methyl)-N,N-dimethylaniline (BNP-Cl) and 4-((3-((3-chloropyridin-4-yl)imino)propenyl)-N,N-dimethylaniline (CNP-Cl), were prepared by combining a pyridine moiety with a cinnamaldehyde or a benzaldehyde moiety. The pyridine moiety contains a chlorine atom, and this chlorine atom is replaced by the nitrogen or oxygen of glyphosate (Glyp) in ACN/Tris buffer (pH=8.14, 10 mM, v/v 2:1). This binding caused color changes ranging from colorless to yellow for BNP-Cl and yellow to orange for CNP-Cl. The sensors BNP-Cl and CNP-Cl have a rapid and excellent selectivity for glyphosate with low detection limits (1.78 µM for BNP-Cl and 1.60 µM for CNP-Cl). The sensors were also successfully applied to detect Glyp in real samples such as soil, tap water, and potatoes.
