GC Determination of Decabromodiphenyl Ether in Electronic Products

提出了气相色谱法测定电子产品中十溴联苯醚的方法。样品先后用甲苯超声提取和浓硫酸提取,所得有机相经硅胶层析柱净化和二氯甲烷洗脱后,以PCb-103为内标物,采用气相色谱法,用电子捕获检测器检测。十溴联苯醚与内标峰面积的比值对十溴联苯醚与内标物质量浓度比值在0.01--10.0 Mg.l-1范围内呈线性,检出限(3S/n)为8.0μg.kg-1。方法用于电视机塑料外壳中十溴联苯醚的测定,相对标准偏差(n=5)为2.2%--8.9%,回收率在92.1%--95.3%之间。Contents of decabromodiphenyl ether(BDE-209) in electronic products was determined by GC.The sample was extracted with toluene and con.H2SO4 in succession.The organic phase was purified and concentrated on silica-gel chromatographic column and eluted with dichloromethane.The dluate was used for GC-ECD analysis after adding PCB-103 as internal standard.Linear relationship between values of peak area ratios of the BDE-209 standard to internal standard and mass concentration of BDE-209 was obtained in the range of 0.01-10.0 mg·L-1,with detection limit(3S/N) of 8.0 μg·kg-1.The proposed method was applied to the analysis of plastic shells of TV-sets,giving values of RSD′s(n=5) in the range of 2.2%-8.9% and recovery in the range of 92.1%-95.3%.国家基础科学人才培养基金(J0630429

Determination of 19 Organophosphorous Pesticides Residues in Milk Drink and Milk Powder by Gas Chromatography-Negative Chemical Ionization-Mass Spectrometry

将气相色谱-负离子化学源质谱法(GC-NCIMS)应用于牛奶饮品和奶粉中19种有机磷农药残留的同时分析。牛奶饮品和奶粉经乙腈提取剂超声提取、Florisil硅藻土和中性氧化铝双净化剂同时净化及正己烷-乙酸乙酯(体积比1∶1)混合洗脱剂洗脱后,以三苯基磷酸酯为内标物,采用GC-NCI MS的选择离子监测方式(SIM)定性与定量分析。当牛奶饮品和奶粉的加标浓度水平为20、100、500μg/kg时,平均加标回收率为64.5%~129%,相对标准偏差为2%~20%;除喹硫磷的方法检出限(MDL)为2.4μg/kg外,其余18种有机磷农药的MDL均小于1.0μg/kg;线性范围为10~500μg/kg,相关系数均大于0.9988,此分析方法成功地应用于牛奶饮品和奶粉中多种痕量有机磷农药残留的分析。A rapid method was developed for the determination of 19 organophosphorous pesticides residues in commercial milk drink and milk powder.Under optimized conditions,the pesticides were extracted from milk drink or milk powder with acetonitrile in an ultrasonic bath and cleaned up on a Florisil and neutral alumina column,and were determined by gas chromatography with negative chemical ionization mass spectrometric detection in the selected ion monitoring mode with triphenyl phosphate as internal standard.The recoveries for all the pesticides studied ranged from 64.5% to 129% with a relative standard deviation range of 2%-20%.The detection limit of the method was less than 1.0 μg/kg for most of the pesticides except for the quinolphos.The linear ranges of the calibration curves ranged from 10 μg/kg to 500 μg/kg with correlation coefficients of 0.998 8.The proposed method was successfully applied to the analysis of these compounds in milk drink and milk powder

Determination of Five Polybrominated Diphenyl Ether Residues in Deep-Sea Fish Oil Using Gas Chromatography-Negative Chemical Ionization/Mass Spectrometry

建立了气相色谱-负离子化学电离质谱法(GC-NCI/MS)同时分析深海鱼油食品中5种多溴联苯醚残留的分析方法。深海鱼油食品用正己烷超声提取、中性与酸性硅胶色谱柱净化和正己烷洗脱后,以PCB103为内标物,采用GC-NCI/MS的选择离子监测方式(SIM)分析;同时探讨了5种多溴联苯醚的NCI/MS特征离子的断裂机理。当空白深海鱼油食品的加标浓度为20.0和100.0μg/kg时,加标回收率为88.6%-111.3%,相对标准偏差为3.8%-13.5%,方法的检测限为0.77-1.34μg/kg,线性范围为1.0-500.0μg/kg,相关系数均大于0.999 2。此方法已成功地应用于深海鱼油食品中5种痕量多溴联苯醚残留的同时分析。Polybrominated diphenyl ethers(PBDEs) are a kind of brominated flame retardants(BFRs),which refer to compounds used in some plastics to impede or even suppress the combustion process.As the emission or disposal of plastics,PBDE residues have been found in both environment and biota.In this work,an analytical method was developed for the simultaneous determination of 5 PBDE residues in deep-sea fish oil.PBDEs were extracted from deep-sea fish oil with n-hexane,cleaned up on a silical gel column,and determined by using gas chromatography-negative chemical ionization/mass spectrometry(GC-NCI/MS) in the selected ion-monitoring(SIM) mode,with PCB103 as the internal standard.Meanwhile,the characteristic ion and fragmentation mechanism of some PBDEs in NCI/MS were evaluated.Recovery studies were performed at 20.0 and 100.0 μg/kg fortification levels for each PBDE,and the recoveries ranged from 88.6% to 111.3% with relative standard deviations between 3.8% and 13.5% for different PBDEs.The limits of detection(LOD) were from 0.77 to 1.34 μg/kg for different PBDEs.The developed method was linear over the range assayed,1.0-500.0 μg/kg,with correlation coefficients larger than 0.999 2.The developed method has also been successfully applied to the determination of PBDEs in several deep-sea fish oil samples and the three most abundant PBDEs(PBDE-47,PBDE-99 and PBDE-100) were found

原子核质量的高精度测量；Precise mass measurement of nuclides

原子核的质量直接反映了核内强相互作用、电磁相互作用和弱相互作用的结果.文章简要阐述了原子核质量测量的意义、现状和主要方法,介绍了基于兰州重离子冷却储存环的原子核质量测量实验,比较了首次得到的63Ge,65As,67Se和71Kr核质量测量值与理论计算结果,探讨了65As质量对天体物理快质子俘获过程的影响,文章最后给出了今后的研究内容.中国科学院近代物理研究所在轻质量丰中子区,系统测量了从Ne到Ca核素的质量,研究了N=20和28幻数随中子数和质子数变化的演化;在丰质子区,精确测量了快质子俘获路径上关键核素的质量,为解释X射线暴等爆发性天体过程提供重要的质量数据;在中重丰中子区,系统地测量丰中子核质量,通过天体网络计算模拟超新星爆发中的快中子俘获过程

Multiresidue determination of polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) in egg samples by gas chromatography-mass spectrometry

建立了气相色谱-负离子化学源-质谱法(gC-nCI-MS)同时分析禽蛋食品中10种多溴联苯(PbbS)和多溴联苯醚(PbdES)残留的分析方法。禽蛋食品用正己烷超声提取、浓硫酸酸化、中性和酸性硅胶层析柱净化和正己烷洗脱后,以PCb209为内标物,采用gC-nCI-MS的选择离子监测方式(SIM)分析;同时探讨了目标物PbdE100 nCI-MS特征离子的断裂机理。当禽蛋食品空白的加标质量浓度为5(3.5)和50(35)μg/kg时,加标回收率为75.2%~107%,相对标准偏差为2.3%~8.8%,方法检测限为0.14~0.39μg/kg,线性范围为1~250μg/kg,相关系数皆大于0.9991,方法已用于禽蛋食品中10种痕量PPbS和PbdES残留的同时分析。A method for the simultaneous determination of 10 PBBs and PBDEs in egg samples was developed.PBBs and PBDEs were extracted from egg samples with hexane and cleaned up on an acid silica gel column,then were determined by using gas chromatography-mass spectrometry operated in negative chemical ionization mode and quantified in selective ion monitoring mode,and with PCB209 as internal standard.Meanwhile,fragmentation mechanism of PBDE100 negative chemical ionization mass spectrometry was evaluated.Recovery studies were performed at 5(3.5) and 50(35) μg/kg fortification levels for each PBDEs(PBBs),and the recoveries ranged from 75.2% to 107% with relative standard deviations between 2.3% and 8.8% for the different PBDEs and PBBs.The developed method was linear over the range of 1～250 μg/kg,with correlation coefficients more than 0.9991.Finally,the developed analytical method has been applied to the determination of PBDEs and PBBs in several egg samples.国家基础科学人才培养基金(J0630429)项目资

Determination of five polybrominated diphenyl ethers in tea leaves by gas chromatography-mass spectrometry-negative chemical ionization

将气相色谱-负离子化学源-质谱法(GC-NCI-MS)应用于快速分析茶叶中5种多溴联苯醚残留量。茶叶样品以正己烷作为提取剂,采用超声辅助提取法,提取液经中性氧化铝和Florisil硅藻土层析柱净化和正己烷洗脱后,以PCB-103为内标物和GC-NCI-MS的选择离子监测方式(SIM)进行定性与定量分析。5种多溴联苯醚的平均加标回收率为70.9%~81.7%,相对标准偏差为6.9%~11.0%,方法检出限小于0.12μg/kg,线性范围为0.1~500μg/kg,相关系数都大于0.9990。所分析的8种茶叶样品中6种含有微量的PBDE-47,1种茶叶样品含有微量的PBDE-99。A rapid method based on ultrasonic extraction was developed for the determination of five polybrominated diphenyl ethers in tea leaves.Hexane was used as the extraction solvent and elution solvent,after the extraction was cleaned by the cartridge filling with alumina and Florisil,the analysis of samples was accomplished using gas chromatography with negative chemical ionization mass spectrometric detection(GC-NCI-MS) in the selected ion monitoring mode(SIM),and with PCB-103 as internal standard(IS).The average recoveries of the standard samples spiked ranged from 70.9% to 81.7% with relative standard deviation between 6.9 and 11.0% for the five different polybrominated diphenyl ethers(PBDEs),and the detection limit of the method was smaller than 0.12 μg/kg.The lineer range is from 0.1 to 500 μg/kg,and the correlation coefficients were larger than 0.9990.Six out of the eight determinated tea leaves had PBDE-47,and one had PBDE99