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
A new molecularly imprinted solid-phase extraction（MISPE） monolithic cartridge was synthesized, and MISPE-DLLME（DLLME=dispersive liquid-liquid microextraction） was developed for purification of astaxanthin in shri...A new molecularly imprinted solid-phase extraction（MISPE） monolithic cartridge was synthesized, and MISPE-DLLME（DLLME=dispersive liquid-liquid microextraction） was developed for purification of astaxanthin in shrimp waste. The eluent（methanol） from MISPE was used as the dispersive solvent in subsequent DLLME for further purifying and enriching the analyte prior to high-performance liquid chromatography（HPLC） analysis. The mobile phase was methanol-acetonitrile-water-dichloromethane（85：5：5：5, volume ratio）, flow rate was 0.7 mL/min and UV wavelength was 476 nm. Under optimal conditions, good linearity was obtained in a range of 0.2--200.0 lug/mL（r2=0.9998） with a limit of detection（LOD） of 0.08 Hg/mL, and the extraction recoveries at three spiked levels ranged from 88.3%--92.5% with a relative standard deviation（RSD） less than 4.3%. Moreover, the mean contents of astaxanthin in the three batches of shrimp waste were 95.9, 85.4 and 77.2 μg/g, respectively. This method combining the advantages of MISPE and DLLME results in high selectivity and low cost, which was applied to determining the astaxanthin level in shrimp waste samples.展开更多
将分散固相萃取和分散液液微萃取(d-SPE-DLLME)相结合,并与气相色谱-三重四极杆质谱(GC-MS/MS)联用,建立了快速测定茶叶中7种拟除虫菊酯类农药残留的方法。样品经乙腈提取,N-丙基乙二胺(PSA)和多壁碳纳米管(MWCNTs)净化,四氯化碳(CCl_4...将分散固相萃取和分散液液微萃取(d-SPE-DLLME)相结合,并与气相色谱-三重四极杆质谱(GC-MS/MS)联用,建立了快速测定茶叶中7种拟除虫菊酯类农药残留的方法。样品经乙腈提取,N-丙基乙二胺(PSA)和多壁碳纳米管(MWCNTs)净化,四氯化碳(CCl_4)浓缩萃取后,采用GC-MS/MS进行分析。以全发酵红茶为基质,考察了提取剂种类、萃取剂的种类和体积、分散剂体积以及萃取时间对萃取效率的影响。以乙腈为提取剂进行分散固相萃取,在进行分散液液微萃取时,以200μL CCl4为萃取剂,1 m L乙腈为分散剂,萃取时间为1 min。结果表明,7种拟除虫菊酯类农药在10~500μg/kg浓度范围内线性关系良好,定量下限为1.0~10.0μg/kg。7种农药在4种茶叶(红茶、绿茶、乌龙茶和黑茶)中4个添加水平下的平均回收率为75.4%~113.6%,相对标准偏差(RSD,n=5)不大于8.8%。该方法具有简单、快速、成本低、检出限低的特点。应用所建立的方法对12种市售茶叶样品进行检测,结果满意。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.
文摘A new molecularly imprinted solid-phase extraction（MISPE） monolithic cartridge was synthesized, and MISPE-DLLME（DLLME=dispersive liquid-liquid microextraction） was developed for purification of astaxanthin in shrimp waste. The eluent（methanol） from MISPE was used as the dispersive solvent in subsequent DLLME for further purifying and enriching the analyte prior to high-performance liquid chromatography（HPLC） analysis. The mobile phase was methanol-acetonitrile-water-dichloromethane（85：5：5：5, volume ratio）, flow rate was 0.7 mL/min and UV wavelength was 476 nm. Under optimal conditions, good linearity was obtained in a range of 0.2--200.0 lug/mL（r2=0.9998） with a limit of detection（LOD） of 0.08 Hg/mL, and the extraction recoveries at three spiked levels ranged from 88.3%--92.5% with a relative standard deviation（RSD） less than 4.3%. Moreover, the mean contents of astaxanthin in the three batches of shrimp waste were 95.9, 85.4 and 77.2 μg/g, respectively. This method combining the advantages of MISPE and DLLME results in high selectivity and low cost, which was applied to determining the astaxanthin level in shrimp waste samples.
文摘将分散固相萃取和分散液液微萃取(d-SPE-DLLME)相结合,并与气相色谱-三重四极杆质谱(GC-MS/MS)联用,建立了快速测定茶叶中7种拟除虫菊酯类农药残留的方法。样品经乙腈提取,N-丙基乙二胺(PSA)和多壁碳纳米管(MWCNTs)净化,四氯化碳(CCl_4)浓缩萃取后,采用GC-MS/MS进行分析。以全发酵红茶为基质,考察了提取剂种类、萃取剂的种类和体积、分散剂体积以及萃取时间对萃取效率的影响。以乙腈为提取剂进行分散固相萃取,在进行分散液液微萃取时,以200μL CCl4为萃取剂,1 m L乙腈为分散剂,萃取时间为1 min。结果表明,7种拟除虫菊酯类农药在10~500μg/kg浓度范围内线性关系良好,定量下限为1.0~10.0μg/kg。7种农药在4种茶叶(红茶、绿茶、乌龙茶和黑茶)中4个添加水平下的平均回收率为75.4%~113.6%,相对标准偏差(RSD,n=5)不大于8.8%。该方法具有简单、快速、成本低、检出限低的特点。应用所建立的方法对12种市售茶叶样品进行检测,结果满意。
文摘将基质固相分散、离子液体均相液-液微萃取和高效液相色谱法相结合,建立一种用于肌肉组织中依诺沙星、培氟沙星、诺氟沙星和恩诺沙星4种氟喹诺酮类药物的分析方法。首先以硅胶为分散剂,以200μL 1-己基-3-甲基咪唑四氟硼酸盐([C_6mim]BF_4)离子液体为萃取剂,p H 1.0水溶液为洗脱剂,采用基质固相分散法处理样品,目标分析物被转移至洗脱液中后,再以六氟磷酸铵为离子对试剂,采用均相液-液微萃取法分离、富集目标分析物于离子液体相中,最后通过高效液相色谱-二极管阵列检测器对目标物进行定量分析。结果表明,各化合物在线性范围内具有较好的线性关系(r>0.997 4),检出限为2.9~8.6μg/kg,加标回收率在87.9%~105.3%之间,其相对标准偏差为2.2%~8.6%。本法操作简单,不使用有机溶剂,可广泛应用于动物肌肉组织中氟喹诺酮类抗生素的萃取与检测。
