The process of ultrasound-assisted dispersive liquid-liquid microextraction(USADLLME) was successfully applied for the extraction and preconcentration of trace copper from water samples,prior to flame atomic absorptio...The process of ultrasound-assisted dispersive liquid-liquid microextraction(USADLLME) was successfully applied for the extraction and preconcentration of trace copper from water samples,prior to flame atomic absorption spectrometry(FAAS).In the proposed approach,1-(2-pyridylazo)-2-naphthol(PAN) was used as a chelating agent and carbon tetrachloride was selected as extraction solvent.Under the optimized experimental conditions(extraction solvent volume:80 μL;pH=5.00;PAN amount:10-6 mol;extraction time:15 min and extraction temperature:40°C),an enrichment factor of 14.3 was obtained from only 6.00 mL of water sample.The calibration graph was linear in the range of 10.00～500.00 μg/L with a detection limit of 0.85 μg/L.The relative standard deviation(RSD) for eleven replicate measurements of 20.00 and 400.00 μg/L of copper were 3.71 and 3.20%.The method was applied to the analysis of tap,river,and sea water samples and good spiked recoveries over the range of 90.4～100.5% were obtained.展开更多
建立了一种简单高效的超声辅助离子液体分散液液微萃取(UA-IL-DLLME)结合石墨炉原子吸收光谱法(GFAAS)测定食品中超痕量铅镉。以二乙基二硫代磷酸铵(DDTP)为配位剂,离子液体1-丁基-3-甲基咪唑六氟磷酸盐[C_4Mim][PF_6]为萃取剂,超声用...建立了一种简单高效的超声辅助离子液体分散液液微萃取(UA-IL-DLLME)结合石墨炉原子吸收光谱法(GFAAS)测定食品中超痕量铅镉。以二乙基二硫代磷酸铵(DDTP)为配位剂,离子液体1-丁基-3-甲基咪唑六氟磷酸盐[C_4Mim][PF_6]为萃取剂,超声用于辅助分散离子液体和加速传质。考察优化了影响萃取效率的主要参数如离子液体的种类和体积、样品液p H、螯合剂的用量、超声时间、离心转速与时间等。在最优的萃取条件下,镉铅的校准曲线分别在0.05~20μg/L和0.5~40μg/L范围呈良好的线性,相关系数分别为0.9983 and 0.9969,检出限(S/N=3)分别为0.032和0.32μg/kg,相对标准偏差(RSD,n=11)分别为1.3%和1.8%。大米和白兰地中镉铅3个水平1.60、16.00、32.00μg/kg的平均加标回收率在95.2~102%范围。方法已成功用于检测不同食品中镉铅含量。展开更多
文摘The process of ultrasound-assisted dispersive liquid-liquid microextraction(USADLLME) was successfully applied for the extraction and preconcentration of trace copper from water samples,prior to flame atomic absorption spectrometry(FAAS).In the proposed approach,1-(2-pyridylazo)-2-naphthol(PAN) was used as a chelating agent and carbon tetrachloride was selected as extraction solvent.Under the optimized experimental conditions(extraction solvent volume:80 μL;pH=5.00;PAN amount:10-6 mol;extraction time:15 min and extraction temperature:40°C),an enrichment factor of 14.3 was obtained from only 6.00 mL of water sample.The calibration graph was linear in the range of 10.00～500.00 μg/L with a detection limit of 0.85 μg/L.The relative standard deviation(RSD) for eleven replicate measurements of 20.00 and 400.00 μg/L of copper were 3.71 and 3.20%.The method was applied to the analysis of tap,river,and sea water samples and good spiked recoveries over the range of 90.4～100.5% were obtained.
文摘建立了一种简单高效的超声辅助离子液体分散液液微萃取(UA-IL-DLLME)结合石墨炉原子吸收光谱法(GFAAS)测定食品中超痕量铅镉。以二乙基二硫代磷酸铵(DDTP)为配位剂,离子液体1-丁基-3-甲基咪唑六氟磷酸盐[C_4Mim][PF_6]为萃取剂,超声用于辅助分散离子液体和加速传质。考察优化了影响萃取效率的主要参数如离子液体的种类和体积、样品液p H、螯合剂的用量、超声时间、离心转速与时间等。在最优的萃取条件下,镉铅的校准曲线分别在0.05~20μg/L和0.5~40μg/L范围呈良好的线性,相关系数分别为0.9983 and 0.9969,检出限(S/N=3)分别为0.032和0.32μg/kg,相对标准偏差(RSD,n=11)分别为1.3%和1.8%。大米和白兰地中镉铅3个水平1.60、16.00、32.00μg/kg的平均加标回收率在95.2~102%范围。方法已成功用于检测不同食品中镉铅含量。
