气相色谱-质谱联用检测塑料产品中溴化阻燃剂

建立了气相色谱-质谱联用测定塑料产品中多溴联苯和多溴联苯醚的方法.以甲苯为提取溶剂,超声提取电子电气产品中多溴联苯(PBBs)和多溴联苯醚 (PBDEs),采用气相色谱-质谱法(GC-MS)检测.SCAN和SIM同时扫描,采用质谱特征离子定量分析.结果表明: 9种多溴联苯(PBBs)和10种多溴联苯醚(PBDEs)的线性关系、检出限、回收率和精密度都较好,RSD均<5.0%,PBBs回收率在97%～111%之间;PBDEs回收率在82%～115%之间.本方法前处理简便,灵敏度高,定性、定量分析准确可靠,且分析时间短,适用于塑料产品中PBBs和PBDEs的测定.     

气相色谱质谱法分析土壤中多溴联苯和多溴联苯醚类化合物

建立了气相色谱-质谱法(GC-MS)分析土壤中的18种多溴联苯(PBBs)和多溴联苯醚类(PBDEs)化合物的方法.利用快速溶剂萃取(ASE)技术和凝胶净化系统(GPC)进行土壤样品的前处理,(13)C标记物作为进样内标和替代标,采用电子轰击源气相色谱质谱法(GC-EI/MS )分析-溴至七溴代PBBs和PBDEs,负...     

气相色谱-质谱法测定电子电气产品中多溴二苯醚及多溴联苯

建立了利用气相色谱-质谱测定电子、电气产品中多溴二苯醚及多溴苯的方法。对样品的粉碎、提取方法、色谱柱的选择、测定条件进行研究,并自建标准质谱图库;采用保留时间、Br同位素规则、质谱特征离子、谱库检索等4种方式相结合进行定性,避免了假阳性及漏检的情况,结果更加准确可靠。本法检出限为5mg/kg,PBDEs的回收率为91.3%,PBBs的回收率为92.5%,相对标准偏差(RSD)为4.3%。与现有方法相比,本法分离时间最短(6min),具有简便快速、实用性强、灵敏度高、准确可靠等特点,适用于电子电气产品、塑料、橡胶、汽车内饰材料等的溴系阻燃剂分析,满足欧盟RoHS指令检测的要求。     

气相色谱-负离子化学源-质谱法分析禽蛋食品中10种多溴联苯和多溴联苯醚残留

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。     

同位素稀释-高分辨气相色谱/高分辨质谱法测定大气中多溴联苯醚和多溴联苯153

针对环境监测的特点和要求,建立了同位素稀释-高分辨气相色谱/高分辨质谱测定大气中多溴联苯醚(PBDEs)和多溴联苯153(BB153)的方法。采用正己烷/二氯甲烷(1:1, v/v)及正己烷分别对PBDEs和BB153进行快速溶剂萃取,并通过复合硅胶柱净化。在校准曲线最高浓度的10%和90%加标水平下得到的天然内标的平均回收率分别为100%和104%,平均相对标准偏差(n=7)分别为5%和6%;二至十溴代联苯醚和BB153相应的¹³C同位素标准物质回收率在36.5%~133%之间;而一溴代联苯醚¹³C同位素标准物质回收率较差,可能是由于物化性质与其他化合物不同。在实际采样体积为300 m³的情况下,未发生污染物穿透现象;分析物检出限低于2×10^-4 ng/Nm³,提取内标回收率在56%~126%之间(一溴代联苯醚除外)。实验结果表明该方法能对化合物准确定量,适用于大气中二至十溴代联苯醚和BB153的分析。     

QuEChERS—气相色谱—串联质谱测定食品中的多溴联苯和多溴二苯醚类阻燃剂

建立了QuEChERS-气相色谱-串联质谱(GC-MS/MS)法测定食品的多溴联苯和多溴二苯醚类物质。采用正己烷或乙腈提取并浓缩目标物后，用无水MgSO₄、乙二胺-N-丙基硅烷(PSA)和十八烷基硅烷键合硅胶(C18)净化，以DB-5HT色谱柱(15 m×0.25 mm×0.1μm)进行分离，质谱采用电子轰击电离源，在多反应监测模式下进行检测，外标法定量。实验优化了提取条件，比较了提取溶剂的种类和体积、酸的体积对检测结果的影响。结果表明，12种多溴联苯和13种多溴二苯醚共25种目标物均呈现良好线性关系，相关系数(r²)≥0.999,方法的检出限为3～180μg/kg,定量限为10～600μg/kg,平均加标回收率为60.23%～106.97%,相对标准偏差(RSDs,n=6)为0.20%～11.96%。该测定方法操作简单，灵敏度高，适用于食品中多溴联苯和多溴二苯醚类物质的高效分析检出。     

热解分离-气相色谱-质谱联用法测定聚苯乙烯电器外壳中20种多溴联苯和多溴联苯醚

将聚苯乙烯(PS)电器外壳样品预先加工制成能通过1mm筛的细颗粒。取此颗粒样品0.5mg置于样品杯中,在裂解仪上从100℃开始,以20℃·min~(-1)的速率升温至340℃,热解60s,使所测定的20种多溴联苯(PBBs)和多溴联苯醚(PBDEs)热解析出,随即引入DB-1色谱柱,以氦气为载气,在分流进样、程序升温的条件下进行色谱分离,并在电子轰击离子源(EI)和选择离子监测(SIM)模式下进行质谱(MS)测定。上述20种被测物均在100～2 000mg·kg~(-1)内与其对应的峰面积呈线性关系,其检出限(3S/N)均小于15mg·kg~(-1)。在3个浓度水平上进行加标回收试验,测得回收率在77.9%～119%之间,测定值的相对标准偏差(n=7)均小于20%。按此方法分析了3件实样,并用标准方法 GB/T 26125-2011附录A进行对比,结果表明此方法的测定结果与标准方法的测定结果基本一致。     

凝胶渗透色谱-分散固相萃取法同时测定鸡蛋中多溴联苯醚及其衍生物、四溴双酚A和六溴环十二烷

建立了一种同时检测鸡蛋中四溴双酚A(TBBP A)、六溴环十二烷(HBCD)和多溴联苯醚(PBDEs)及其衍生物羟基多溴联苯醚(OH-PBDEs)和甲氧基多溴联苯醚(MeO-PBDEs)的凝胶渗透色谱(GPC)-分散固相萃取(DSPE)-液相色谱-串联质谱(HPLC-MS/MS)和气相色谱-负化学源质谱(GC-NCI/MS)的检测方法。样品经正己烷、二氯甲烷(1∶1,V/V)加速溶剂萃取,凝胶渗透色谱净化后,经100 mg十八烷基键合硅胶(C18)分散固相萃取吸附剂去除杂质,液相色谱-串联质谱和气相色谱-负化学源质谱方法测定,外标法定量。在蛋白和蛋黄样品中添加1.0或5.0μg/kg的目标物,其回收率分别为64.5%~97.2%和65.6%~109.2%(除BDE-85为54.8%,OH-BDE-137为47.4%外),相对标准偏差小于20.2%,定量限为0.01~0.2μg/kg。     

气相色谱-负离子化学源/质谱法(GC-NCI/MS)分析鱼类和贝类样品中多溴联苯醚和多溴联苯

将气相色谱-负离子化学源/质谱法(GC-NCI/MS)应用于分析鱼类和贝类样品中5种多溴联苯醚(PBDEs)和5种多溴联苯(PBBs)残留.鱼类和贝类样品以正己烷/丙酮(1∶1,V/V)作为提取剂,采用超声萃取法,提取液经酸性硅胶和中性硅胶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...     

气相色谱法测定牡蛎中多溴联苯醚

利用气相色谱-电子捕获检测器(GC-ECD),建立了牡蛎中11种多溴联苯醚(PBDEs)同时测定方法。优化了气相法与质谱联用法仪器条件,考察了不同提取溶液、固相萃取柱、净化方式等前处理条件对提取和净化效果的影响。结果表明,GC-ECD对高溴组分更灵敏;牡蛎加标样品经正己烷-二氯甲烷(1:1,V/V)提取,弗洛里硅土柱-浓硫酸净化,GC-ECD测定,PBDEs各组分标准曲线线性良好(r 0. 998),二至九溴联苯醚和十溴联苯醚方法检出限分别为0. 05 ng/g和0. 1 ng/g,回收率范围为80. 3%～104%,相对标准偏差范围为3. 0%～12%。方法可用于牡蛎中二至十溴联苯醚同时检测。     

Furyl- and thienyl-silatranes and germatranes

We review our research on the synthesis and study of the physical and biological properties of furyl- and thienylgermatranes and -silatranes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 725–732, June, 1992.     

Review and patents and literature

The use of the insect cell/baculovirus expression system for producing recombinant proteins of bacterial, plant, insect, and mammalian origin has become widespread. The popularity of this eukaryotic expression system is due to many factors, including (1) potentially high protein expression levels, (2) ease and speed of genetic engineering, (3) ability to accommodate large DNA inserts, (4) protein processing similar to higher eukaryotic cells (e.g., mammalian cells), and (5) ease of insect cell growth (e.g., suspension growth). The following review of the literature discusses two engineering aspects of recombinant protein synthesis by insect cell cultures: bioreactor scale-up and insect cell line selection. Following this review patent abstracts and additional literature pertaining to expression of recombinant proteins in insect cell culture are listed.     

Ground- and excited-state aromaticity and antiaromaticity in benzene and cyclobutadiene

The aromaticity and antiaromaticity of the ground state (S 0), lowest triplet state (T 1), and first singlet excited state (S 1) of benzene, and the ground states (S 0), lowest triplet states (T 1), and the first and second singlet excited states (S 1 and S 2) of square and rectangular cyclobutadiene are assessed using various magnetic criteria including nucleus-independent chemical shifts (NICS), proton shieldings, and magnetic susceptibilities calculated using complete-active-space self-consistent field (CASSCF) wave functions constructed from gauge-including atomic orbitals (GIAOs). These magnetic criteria strongly suggest that, in contrast to the well-known aromaticity of the S 0 state of benzene, the T 1 and S 1 states of this molecule are antiaromatic. In square cyclobutadiene, which is shown to be considerably more antiaromatic than rectangular cyclobutadiene, the magnetic properties of the T 1 and S 1 states allow these to be classified as aromatic. According to the computed magnetic criteria, the T 1 state of rectangular cyclobutadiene is still aromatic, but the S 1 state is antiaromatic, just as the S 2 state of square cyclobutadiene; the S 2 state of rectangular cyclobutadiene is nonaromatic. The results demonstrate that the well-known "triplet aromaticity" of cyclic conjugated hydrocarbons represents a particular case of a broader concept of excited-state aromaticity and antiaromaticity. It is shown that while electronic excitation may lead to increased nuclear shieldings in certain low-lying electronic states, in general its main effect can be expected to be nuclear deshielding, which can be substantial for heavier nuclei.     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

Syntheses and structures of P-anilino-P-chalcogeno- and P-anilino-P-iminodiazasilaphosphetidines and their group 12 and 13 metal compounds

The P-anilino-P-chalcogeno(imino)diazasilaphosphetidines [Me(2)Si(mu-N(t)Bu)(2)P=E(NHPh)] (E = O (3), S (4), Se (5), N-p-tolyl (6)) were synthesized by oxidizing the P-anilinodiazasilaphosphetidine [Me(2)Si(N(t)Bu)(2)P(NHPh)] (2) with cumene hydroperoxide, sulfur, selenium, and p-tolyl azide, respectively. The lithium salt of 4 reacted with thallium monochloride to produce ([Me(2)Si(mu-N(t)Bu)(2)P=S(NPh)-kappaN-kappaS]Tl)(7), which features a two-coordinate thallium atom. Treatment of 4-6 with AlMe(3) gave the monoligand dimethylaluminum complexes ([Me(2)Si(mu-N(t)Bu)(2)P=E(NPh)-kappaN-kappaE]AlMe(2)) (E = S (8), Se (9), N-p-tolyl (10)), respectively. In these complexes the aluminum atom is tetrahedrally coordinated by one chelating ligand and two methyl groups, as a single-crystal X-ray analysis of 8 showed. A 2 equiv amount of 4-6 reacted with diethylzinc to produce the homoleptic diligand complexes ([Me(2)Si(mu-N(t)Bu)(2)P=E(NPh)-kappaN-kappaE](2)Zn)(E = S (11), Se (12), N-p-tolyl (13)). A crystal-structure analysis of 11 revealed a linear tetraspirocycle with a tetrahedrally coordinated, central zinc atom.