Analysis of pesticide residue levels in juice beverages is important to ensure safe consumption and avoid global trade concerns associated to pesticide contaminations.A simple,inexpensive and effective method was deve...Analysis of pesticide residue levels in juice beverages is important to ensure safe consumption and avoid global trade concerns associated to pesticide contaminations.A simple,inexpensive and effective method was developed for the determination of organochlorine pesticides(OCPs)in bottled juice drinks using GC-MS.Sample pretreatment was performed using dispersive solid-phase microextraction(D-μ-SPE)for matrix desorption and dispersive liquid-liquid microextraction(DLLME)for analyte enrichment.In this study,an affordable and effective sorbent for the adsorption of OCPs from juice samples was synthesized from avocado seeds mixed with magnetic precursors for D-μSPE.The ground avocado seeds combined with a magnetic precursor nanocomposite were characterized using various instruments including scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and Brunauer-Emmett-Teller(BET)analysis.The solution obtained from D-μ-SPE desorption was used as a dispersant for the subsequent DLLME,which made the combination of D-μ-SPE with DLLME much easier.The effectiveness of the method was enhanced by optimizing the influential parameters in both D-μ-SPE and DLLME.Then after,the optimal values were determined for the real sample analysis.Accordingly,there was good linear dynamic range with a coefficient of determination(r2)≥0.9989.The limit of detection and quantification were 0.02–0.69 and 0.06–2.10 ng/L respectively.The method showed high enrichment factors ranging from 96 to 313 with recoveries of 87–100%.Intraday and interday precisions were≤4%.Compared with other reported methods,this method is a one-step,simple,cheap,fast,and environmentally friendly alternative and straightforward method for adsorbing organochlorine pesticides from sample solutions.These results demonstrates the high potential of the proposed method for the extraction and cleanup of contaminants in selected juices and other related samples.展开更多
In this work,Fe3O4-Al2O3@CNFs nanocomposite was synthesised and used as a nanosorbent in the ultrasound-assisted dispersive magnetic solid phase extraction(UA-DMSPE)of 17-beta estradiol(E2)in wastewater samples.The qu...In this work,Fe3O4-Al2O3@CNFs nanocomposite was synthesised and used as a nanosorbent in the ultrasound-assisted dispersive magnetic solid phase extraction(UA-DMSPE)of 17-beta estradiol(E2)in wastewater samples.The quantification of E2 was achieved using high performance liquid chromatography coupled with diode array detector(HPLC-DAD).Various parameters affecting the efficiency of this sample preparation technique were optimised to achieve excellent sensitivity and high recoveries of E2.Response surface methodology was utilised for optimisation of these parameters.Using the optimised conditions,the linear dynamic range was achieved in the range of 0.1e1000 mgL^-1and the correlation coefficient was found to be 0.9981.The preconcentration factor,enrichment factor,limit of detection(LOD)and limit of quantification(LOQ)were 67,169,0.025 mgL^-1and 0.083 mg L1,respectively.The relative standard deviation(%RSD)for the intraday(n?10)and interday(n?5 working days)were 1.8%and 3.3%,respectively.The developed UA-DMSPE/HPLC-DAD method was applied for the preconcentration and determination of E2 in wastewater samples.The obtained results indicated that E2 was present in the wastewater samples.展开更多
基金This work was financially supported by the College of Natural Sciences,Jimma University through the grand research project(CNS-Chem-11-2020/21-SP1).
文摘Analysis of pesticide residue levels in juice beverages is important to ensure safe consumption and avoid global trade concerns associated to pesticide contaminations.A simple,inexpensive and effective method was developed for the determination of organochlorine pesticides(OCPs)in bottled juice drinks using GC-MS.Sample pretreatment was performed using dispersive solid-phase microextraction(D-μ-SPE)for matrix desorption and dispersive liquid-liquid microextraction(DLLME)for analyte enrichment.In this study,an affordable and effective sorbent for the adsorption of OCPs from juice samples was synthesized from avocado seeds mixed with magnetic precursors for D-μSPE.The ground avocado seeds combined with a magnetic precursor nanocomposite were characterized using various instruments including scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and Brunauer-Emmett-Teller(BET)analysis.The solution obtained from D-μ-SPE desorption was used as a dispersant for the subsequent DLLME,which made the combination of D-μ-SPE with DLLME much easier.The effectiveness of the method was enhanced by optimizing the influential parameters in both D-μ-SPE and DLLME.Then after,the optimal values were determined for the real sample analysis.Accordingly,there was good linear dynamic range with a coefficient of determination(r2)≥0.9989.The limit of detection and quantification were 0.02–0.69 and 0.06–2.10 ng/L respectively.The method showed high enrichment factors ranging from 96 to 313 with recoveries of 87–100%.Intraday and interday precisions were≤4%.Compared with other reported methods,this method is a one-step,simple,cheap,fast,and environmentally friendly alternative and straightforward method for adsorbing organochlorine pesticides from sample solutions.These results demonstrates the high potential of the proposed method for the extraction and cleanup of contaminants in selected juices and other related samples.
基金the Department of Science and Technology(DST,South Africa)/National Nanoscience Postgraduate Teaching and Training Programme(NNPTTP)and National Research Foundation(NRF,South Africa,grant no.99270&91230).
文摘In this work,Fe3O4-Al2O3@CNFs nanocomposite was synthesised and used as a nanosorbent in the ultrasound-assisted dispersive magnetic solid phase extraction(UA-DMSPE)of 17-beta estradiol(E2)in wastewater samples.The quantification of E2 was achieved using high performance liquid chromatography coupled with diode array detector(HPLC-DAD).Various parameters affecting the efficiency of this sample preparation technique were optimised to achieve excellent sensitivity and high recoveries of E2.Response surface methodology was utilised for optimisation of these parameters.Using the optimised conditions,the linear dynamic range was achieved in the range of 0.1e1000 mgL^-1and the correlation coefficient was found to be 0.9981.The preconcentration factor,enrichment factor,limit of detection(LOD)and limit of quantification(LOQ)were 67,169,0.025 mgL^-1and 0.083 mg L1,respectively.The relative standard deviation(%RSD)for the intraday(n?10)and interday(n?5 working days)were 1.8%and 3.3%,respectively.The developed UA-DMSPE/HPLC-DAD method was applied for the preconcentration and determination of E2 in wastewater samples.The obtained results indicated that E2 was present in the wastewater samples.
