A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrumen...A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and p H on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without Na Cl addition at p H=9. Good linearity(R2=0.9997) was obtained when the linear range was 10-500 μg/L. The recoveries of β-ionone in ultrapure water and tap water samples were 88%-95% and 110%-114%, respectively. The relative standard deviations(RSD) were less than 10%. The method detection limit(MDL) and rejection quality level(RQL) were achieved at1.98 μg/L and 6.53 μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.展开更多
In order to control drug crime effectively,it is necessary to develop selective analytical methods suitable for unambiguous identification and determination of drugs in illicit samples and biological matrices.A novel ...In order to control drug crime effectively,it is necessary to develop selective analytical methods suitable for unambiguous identification and determination of drugs in illicit samples and biological matrices.A novel microextraction technique based on ultrasound-assisted low-density solvent dispersive liquid-liquid microextraction,(UA-LDS-DLLME)has been applied to the determination of four amphetamines(methamphetamine,amphetamine,3,4-methylenedioxymethamphetamine,and 3,4-methylenedioxyamphetamine)in urine samples by gas chromatography-mass spectrometry.The parameters affecting extraction efficiency have been investigated and optimized.UA-LDS-DLLME used ultrasound energy to assist in the emulsification process without any disperser solvent.Under the optimized conditions,linearity was observed for all analytes in the 0.15-10 p,g/mL range with correlation coefficients(R)ranging from 0.9886 to 0.9894.The recoveries of75.6-91.4%with relative standard deviations of 2.5-4.0%were obtained.The limits of detection(S/N=3)were estimated to be in the 5-10 ng/mL range.The UA-LDS-DLLME technique had the advantages of shorter extraction time,suitability for simultaneous pretreatments of batches of samples,and the higher extraction efficiency.It was successfully applied to the analysis of amphetamines in real human urine samples.展开更多
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
基金Project(51178321)supported by the National Natural Science Foundation of ChinaProject(2012ZX07403-001)supported by the National Science and Technology Major Project,ChinaProject(20120072110050)supported by the Research Fund for the Doctoral Program of Higher Education of China
文摘A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and p H on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without Na Cl addition at p H=9. Good linearity(R2=0.9997) was obtained when the linear range was 10-500 μg/L. The recoveries of β-ionone in ultrapure water and tap water samples were 88%-95% and 110%-114%, respectively. The relative standard deviations(RSD) were less than 10%. The method detection limit(MDL) and rejection quality level(RQL) were achieved at1.98 μg/L and 6.53 μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.
基金supported by Technology Project of Education Department in Fujian:A(JA14336).
文摘In order to control drug crime effectively,it is necessary to develop selective analytical methods suitable for unambiguous identification and determination of drugs in illicit samples and biological matrices.A novel microextraction technique based on ultrasound-assisted low-density solvent dispersive liquid-liquid microextraction,(UA-LDS-DLLME)has been applied to the determination of four amphetamines(methamphetamine,amphetamine,3,4-methylenedioxymethamphetamine,and 3,4-methylenedioxyamphetamine)in urine samples by gas chromatography-mass spectrometry.The parameters affecting extraction efficiency have been investigated and optimized.UA-LDS-DLLME used ultrasound energy to assist in the emulsification process without any disperser solvent.Under the optimized conditions,linearity was observed for all analytes in the 0.15-10 p,g/mL range with correlation coefficients(R)ranging from 0.9886 to 0.9894.The recoveries of75.6-91.4%with relative standard deviations of 2.5-4.0%were obtained.The limits of detection(S/N=3)were estimated to be in the 5-10 ng/mL range.The UA-LDS-DLLME technique had the advantages of shorter extraction time,suitability for simultaneous pretreatments of batches of samples,and the higher extraction efficiency.It was successfully applied to the analysis of amphetamines in real human urine samples.
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.
