Parabens are antimicrobial preservatives with extensive applications in cosmetics,toiletries,pharmaceuticals,and food.Considering the legitimate concerns relating to their potential to disrupt multiple endocrine funct...Parabens are antimicrobial preservatives with extensive applications in cosmetics,toiletries,pharmaceuticals,and food.Considering the legitimate concerns relating to their potential to disrupt multiple endocrine functions,it becomes imperative to prioritize the development of innovative bioanalytical techniques for effectively monitoring their presence in biological samples.In this study,an efficient solvent bar microextraction(SBME)was established,utilizing new hydrophobic deep eutectic solvents(DEs)to determine methylparaben and propylparaben in urine and plasma samples.The DEs comprising menthol and tris(2-ethylhexyl)phosphate(M-TEHP)at various molar ratios were synthesized for the first time to enhance the extraction capacity and promote the eco-friendliness of the DE used as an extraction solvent.Fourier-transform infrared(FT-IR)and proton nuclear magnetic resonance(1H NMR)spectroscopies were employed to confirm and investigate the properties of the successful synthesis(M-TEHP)DE at a molar ratio of 1:1.The synthesized DE exhibits low microbial toxicity and can be considered an eco-friendly solvent for extraction.Furthermore,quantum-chemical calculations were utilized to predict synthesized DE's structure and interaction energy with selected parabens.The influential operational factors of DE-SBME on the extraction efficiency(EE%)of both parabens were evaluated using response surface methodology based on central composite design,and a total of 30 extraction tests were conducted to determine the optimal conditions.The optimized DE-SBME,in combination with HPLC-DAD,exhibited low detection limits(0.54–0.91μg L^(−1)),excellent linearity(R^(2)≥0.9993),precise results(RSDs≤7.6%),satisfactory recoveries(92–97%)and negligible matrix effects.Hence,it had remarkable effectiveness and applicability in determining selected parabens in real urine and plasma samples.展开更多
Cadmium“Cd”is a toxic pollutant that may present in soil and water.This work evaluates:i)the use of non-steroidal anti-inflammatory drugs“NSAIDs”-bearing water for washing soil containing Cd(Ⅱ),ii)removal of Cd(...Cadmium“Cd”is a toxic pollutant that may present in soil and water.This work evaluates:i)the use of non-steroidal anti-inflammatory drugs“NSAIDs”-bearing water for washing soil containing Cd(Ⅱ),ii)removal of Cd(Ⅱ)from NSAID-bearing water by adsorption onto magnetic graphene oxide which can be easily separated by strong magnet.The studied NSAIDs are aspirin,ketoprofen,ibuprofern and diclofenac.The Cd(Ⅱ)-NSAIDs complexes were synthesized and characterized by FT-IR.Graphene was initially oxidized by either nitric acid,or ammonium persulphate method,or Hummer's method.Magnetite was then deposited on graphene oxide to give the corresponding magnetic graphene oxides(NA-MGO,APSMGO and Hum-MGO,respectively).The effect of the following factors on Cd(Ⅱ)uptake was investigated:NSAIDs type,pH,graphene oxidation method,magnetite:graphene oxide mass ratio in the adsorbent,(Cd(Ⅱ):NSAID)molar ratio.Maximum Cd(Ⅱ)uptake was achieved using“magnetic graphene oxidized with ammonium persulphate where the mass ratio of magnetite to graphene oxide was 2:1”in the presence of diclofenac at pH6.The best Cd(Ⅱ):diclofenac molar ratio was 1:3.The maximum adsorption capacity of Cd(Ⅱ)was found to be 83 mg L1.The regeneration of the adsorbent was possible by 0.3 M HNO3 solution and 80%of adsorption efficiency was maintained after five cycles.Upon presence of coexisting ions,80%of the adsorption efficiency was maintained.Various NSAIDs-containing waters were used for washing Cd-containing soil;the maximum removal efficiencies of Cd were 18%and 16%using 5 mM diclofenac or 10 mM aspirin,respectively.Using diclofenac or aspirin-spiked real pharmaceutical wastewater gave 28%removal of Cd.The optimum adsorption method was used for removal of Cd(Ⅱ)from diclofenac-containing soil-washing water,where two successive adsorptions were needed for complete Cd uptake.展开更多
In the present work,two magnetic adsorbents(magnetic carbon nanotunes“MCNT”and magnetite“Mag”)were tested for cadmium“Cd(Ⅱ)”removal from water in the presence of various amino acids“AA”(aspartic acid,glutamic...In the present work,two magnetic adsorbents(magnetic carbon nanotunes“MCNT”and magnetite“Mag”)were tested for cadmium“Cd(Ⅱ)”removal from water in the presence of various amino acids“AA”(aspartic acid,glutamic acid“Glu”,glycine and cysteine).MCNT was prepared by initially oxidizing carbon nanotubes(CNT)by three different methods:nitric acid method,ammonium persulphate method,Hummer's method.Magnetite was then deposited on the oxidized CNT to produce the corresponding magnetic carbon nanotube adsorbents:NA-MCNT,APS-MCNT,HUM-MCNT,respectively.Adsorption of Cd(Ⅱ)on various MCNT was investigated in the presence/absence of AA where various factors were studied:pH,oxidation method of CNT,type of AA,magnetite-to-CNT ratio.It was found that the presence of AA significantly reduced the adsorption capacity of MCNT towards Cd(Ⅱ)at all pHs(reduction occurred from 49.8 mg g^(-1)to 12.5 mg g^(-1)).Contrary adsorption capacity of Cd(Ⅱ)on bare magnetite“Mag”was noticeably enhanced in the presence of AA(for Glu,enhancement occurred from 6.9 to 22.3 mg g^(-1)).Due to cheapness of Mag relative to CNT,it was recommended to use Mag rather than MCNT for Cd(Ⅱ)removal from AA-bearing water.So that the optimum uptake method was proposed using Mag at pH 8 in the presence of Glu at concentration ratio(1:3 Cd(Ⅱ):Glu).Mag was selective towards Cd(Ⅱ)even in the presence of co-existing ions.The use of Mag for five cycles decreased adsorption efficiency to 80%which indicated that adsorption system was cost effective.Real water samples gave higher adsorption of Cd(Ⅱ)in the presence of Glu than in distilled water.As a conclusion,it was recommended to use Mag rather than MCNT for Cd(Ⅱ)removal in the presence of AA.展开更多
This project studied Cd(Ⅱ)uptake from phenols-bearing wastewater using magnetic carbon nanotubes(MCNT)as adsorbent.Initially,Cd(Ⅱ)complexation with various phenols was confirmed by FT-IR spectroscopy.Factors affecti...This project studied Cd(Ⅱ)uptake from phenols-bearing wastewater using magnetic carbon nanotubes(MCNT)as adsorbent.Initially,Cd(Ⅱ)complexation with various phenols was confirmed by FT-IR spectroscopy.Factors affecting Cd removal are:solution pH;type of phenol[phenol(Ph),2-chlorophenol(2-CP),2-nitrophenol(2-NP),and 2,4-dinitrophenol(2,4-DNP)];Mag:CNT mass ratio;Cd:phenolic compound molar ratio;and the effect of order of adding adsorption components(MCNT,Cd(Ⅱ),phenolic compound)to the extraction medium.It was found that the presence of phenols in the extraction medium caused a 10e50%decrease in Cd(Ⅱ)uptake.This was probably due to a competition between phenols/surface functional groups towards Cd(Ⅱ);or phenols/Cd(Ⅱ)to occupy the surface functional groups.2,4-DNP was selected as a model phenolic compound.The optimum adsorption conditions[1:1 M ratio of(Cd(Ⅱ):2,4-DNP)at pH 6 using MCNT(1:1)adsorbent]resulted in adsorption capacity of 17.9 mg Cd g^(-1).The best order of adding reagents was(Cd(Ⅱ)þMCNT(1:1))and then 2,4-DNP.The regeneration of the adsorbent was possible by using 0.5 M HNO_(3)where 90%of adsorption efficiency was reserved after three times of successive use.Upon presence of co-existing ions,75%of the adsorption efficiency was maintained.The applicability of the proposed adsorption method on real water samples was evaluated.展开更多
文摘Parabens are antimicrobial preservatives with extensive applications in cosmetics,toiletries,pharmaceuticals,and food.Considering the legitimate concerns relating to their potential to disrupt multiple endocrine functions,it becomes imperative to prioritize the development of innovative bioanalytical techniques for effectively monitoring their presence in biological samples.In this study,an efficient solvent bar microextraction(SBME)was established,utilizing new hydrophobic deep eutectic solvents(DEs)to determine methylparaben and propylparaben in urine and plasma samples.The DEs comprising menthol and tris(2-ethylhexyl)phosphate(M-TEHP)at various molar ratios were synthesized for the first time to enhance the extraction capacity and promote the eco-friendliness of the DE used as an extraction solvent.Fourier-transform infrared(FT-IR)and proton nuclear magnetic resonance(1H NMR)spectroscopies were employed to confirm and investigate the properties of the successful synthesis(M-TEHP)DE at a molar ratio of 1:1.The synthesized DE exhibits low microbial toxicity and can be considered an eco-friendly solvent for extraction.Furthermore,quantum-chemical calculations were utilized to predict synthesized DE's structure and interaction energy with selected parabens.The influential operational factors of DE-SBME on the extraction efficiency(EE%)of both parabens were evaluated using response surface methodology based on central composite design,and a total of 30 extraction tests were conducted to determine the optimal conditions.The optimized DE-SBME,in combination with HPLC-DAD,exhibited low detection limits(0.54–0.91μg L^(−1)),excellent linearity(R^(2)≥0.9993),precise results(RSDs≤7.6%),satisfactory recoveries(92–97%)and negligible matrix effects.Hence,it had remarkable effectiveness and applicability in determining selected parabens in real urine and plasma samples.
文摘Cadmium“Cd”is a toxic pollutant that may present in soil and water.This work evaluates:i)the use of non-steroidal anti-inflammatory drugs“NSAIDs”-bearing water for washing soil containing Cd(Ⅱ),ii)removal of Cd(Ⅱ)from NSAID-bearing water by adsorption onto magnetic graphene oxide which can be easily separated by strong magnet.The studied NSAIDs are aspirin,ketoprofen,ibuprofern and diclofenac.The Cd(Ⅱ)-NSAIDs complexes were synthesized and characterized by FT-IR.Graphene was initially oxidized by either nitric acid,or ammonium persulphate method,or Hummer's method.Magnetite was then deposited on graphene oxide to give the corresponding magnetic graphene oxides(NA-MGO,APSMGO and Hum-MGO,respectively).The effect of the following factors on Cd(Ⅱ)uptake was investigated:NSAIDs type,pH,graphene oxidation method,magnetite:graphene oxide mass ratio in the adsorbent,(Cd(Ⅱ):NSAID)molar ratio.Maximum Cd(Ⅱ)uptake was achieved using“magnetic graphene oxidized with ammonium persulphate where the mass ratio of magnetite to graphene oxide was 2:1”in the presence of diclofenac at pH6.The best Cd(Ⅱ):diclofenac molar ratio was 1:3.The maximum adsorption capacity of Cd(Ⅱ)was found to be 83 mg L1.The regeneration of the adsorbent was possible by 0.3 M HNO3 solution and 80%of adsorption efficiency was maintained after five cycles.Upon presence of coexisting ions,80%of the adsorption efficiency was maintained.Various NSAIDs-containing waters were used for washing Cd-containing soil;the maximum removal efficiencies of Cd were 18%and 16%using 5 mM diclofenac or 10 mM aspirin,respectively.Using diclofenac or aspirin-spiked real pharmaceutical wastewater gave 28%removal of Cd.The optimum adsorption method was used for removal of Cd(Ⅱ)from diclofenac-containing soil-washing water,where two successive adsorptions were needed for complete Cd uptake.
文摘In the present work,two magnetic adsorbents(magnetic carbon nanotunes“MCNT”and magnetite“Mag”)were tested for cadmium“Cd(Ⅱ)”removal from water in the presence of various amino acids“AA”(aspartic acid,glutamic acid“Glu”,glycine and cysteine).MCNT was prepared by initially oxidizing carbon nanotubes(CNT)by three different methods:nitric acid method,ammonium persulphate method,Hummer's method.Magnetite was then deposited on the oxidized CNT to produce the corresponding magnetic carbon nanotube adsorbents:NA-MCNT,APS-MCNT,HUM-MCNT,respectively.Adsorption of Cd(Ⅱ)on various MCNT was investigated in the presence/absence of AA where various factors were studied:pH,oxidation method of CNT,type of AA,magnetite-to-CNT ratio.It was found that the presence of AA significantly reduced the adsorption capacity of MCNT towards Cd(Ⅱ)at all pHs(reduction occurred from 49.8 mg g^(-1)to 12.5 mg g^(-1)).Contrary adsorption capacity of Cd(Ⅱ)on bare magnetite“Mag”was noticeably enhanced in the presence of AA(for Glu,enhancement occurred from 6.9 to 22.3 mg g^(-1)).Due to cheapness of Mag relative to CNT,it was recommended to use Mag rather than MCNT for Cd(Ⅱ)removal from AA-bearing water.So that the optimum uptake method was proposed using Mag at pH 8 in the presence of Glu at concentration ratio(1:3 Cd(Ⅱ):Glu).Mag was selective towards Cd(Ⅱ)even in the presence of co-existing ions.The use of Mag for five cycles decreased adsorption efficiency to 80%which indicated that adsorption system was cost effective.Real water samples gave higher adsorption of Cd(Ⅱ)in the presence of Glu than in distilled water.As a conclusion,it was recommended to use Mag rather than MCNT for Cd(Ⅱ)removal in the presence of AA.
文摘This project studied Cd(Ⅱ)uptake from phenols-bearing wastewater using magnetic carbon nanotubes(MCNT)as adsorbent.Initially,Cd(Ⅱ)complexation with various phenols was confirmed by FT-IR spectroscopy.Factors affecting Cd removal are:solution pH;type of phenol[phenol(Ph),2-chlorophenol(2-CP),2-nitrophenol(2-NP),and 2,4-dinitrophenol(2,4-DNP)];Mag:CNT mass ratio;Cd:phenolic compound molar ratio;and the effect of order of adding adsorption components(MCNT,Cd(Ⅱ),phenolic compound)to the extraction medium.It was found that the presence of phenols in the extraction medium caused a 10e50%decrease in Cd(Ⅱ)uptake.This was probably due to a competition between phenols/surface functional groups towards Cd(Ⅱ);or phenols/Cd(Ⅱ)to occupy the surface functional groups.2,4-DNP was selected as a model phenolic compound.The optimum adsorption conditions[1:1 M ratio of(Cd(Ⅱ):2,4-DNP)at pH 6 using MCNT(1:1)adsorbent]resulted in adsorption capacity of 17.9 mg Cd g^(-1).The best order of adding reagents was(Cd(Ⅱ)þMCNT(1:1))and then 2,4-DNP.The regeneration of the adsorbent was possible by using 0.5 M HNO_(3)where 90%of adsorption efficiency was reserved after three times of successive use.Upon presence of co-existing ions,75%of the adsorption efficiency was maintained.The applicability of the proposed adsorption method on real water samples was evaluated.
