固相萃取-超高效液相色谱/串联质谱同时检测饮料中13种禁限用食品添加剂

建立了固相萃取-超高效液相色谱/电喷雾电离串联质谱(SPE-UPLC-MS/MS)同时测定饮料中13种禁限用食品添加剂(甜味剂、防腐剂和色素类物质)的分析方法。样品经过OASIS HLB固相萃取小柱萃取净化后,以0.2mL/min的流速,在WatersBEH C18(50×2.1mm,1.7μm)色谱柱上进行快速分离,流动相为10mmol/L乙酸铵(含0.1%乙酸)和甲醇。根据检测物质的性质,利用不同电离模式(ESI-和ESI+),采用多反应监测模式(MRM)进行测定,在2～500μg/L的范围内,各物质线性相关系数均大于0.990,13种检测物质的检出限为0.20～6.79μg/L;利用Waters HLB固相萃取小柱对目标物质进行萃取,对固相萃取条件进行优化后,10、50、100μg/L三个添加水平下平均回收率为85.6%～110.4%,相对标准偏差(RSD)均小于10%(n=5)。所建立的方法简便,灵敏度高,可以满足对饮料中多种不同食品添加剂的同时测定。     

同位素稀释-液相色谱/质谱法测定生态纺织品中五氯苯酚残留

建立了生态纺织品中五氯苯酚的同位素稀释-固相萃取-液相色谱/串联质谱的分析方法。样品用5%氨水-乙腈溶液(70/30,V/V)提取,用MAX固相萃取小柱净化。以乙腈-水(内含0.1%甲酸和5 mmol/L NH_4Ac)为流动相,采用梯度洗脱,在Shim-pack XR-ODSⅢ色谱柱(100 mm×2.0 mm i.d.,2.2μm)上进行分离,以多反应监测负离子模式进行检测,内标法定量。该方法在0.5～50.0μg/L范围线性关系良好,样品的回收率为80.0%～110.0%,相对标准偏差(RSD)为1.56%～5.39%,定量限为0.5μg/kg,检出限为0.15μg/kg。方法灵敏度高、重现性好,可用于生态纺织品中五氯苯酚的监测。     

超高效液相色谱-串联质谱法同时测定浓缩苹果汁中的4种链格孢霉毒素

建立了浓缩苹果汁中链格孢霉素、链格孢酚、腾毒素、链格孢酚甲醚4种毒素残留量的固相萃取-超高效液相色谱-串联质谱检测方法。样品用水稀释后,用PS DVB固相萃取柱净化,外标法定量。测定时用BEH C18色谱柱(50 mm×2.1 mm, 1.7 μm)分离,乙腈和水梯度洗脱,质谱测定采用多反应监测(MRM)模式。4种链格孢霉毒素的测定低限在1.0～5.0 μg/L范围内,加标回收率为77.8%～117.2%,相对标准偏差均低于9.7%。该方法灵敏、稳定、可靠,可用于浓缩苹果汁样品中4种链格孢霉毒素的检测和确证。     

QuEChERS-高效液相色谱串联质谱法测定鱼血浆中喹烯酮的残留

建立了分散固相萃取-高效液相色谱-串联质谱(QuEChERS-HPLC-MS/MS)测定鱼血浆中喹烯酮残留的分析方法。血浆样品经乙腈萃取,采用乙二胺-N-丙基硅烷(PSA)与石墨化炭黑(GCB)为吸附剂进行固相分散净化。用Xtrerra C18(3.5μm,4.6 mm i.d.×150 mm)色谱柱分离,电喷雾正离子(ESI+)模式电离,多反应监测模式检测,外标法定量。方法在5～100μg/L范围内有较好的线性关系,相关系数大于0.998,方法检出限为1.5μg/L,定量限为5μg/L。采用该方法对空白血浆检测并进行加标回收实验,在5和25μg/L两个添加水平下,加标回收率大于90%,相对标准偏差(n=3)低于7.2%。     

在线固相萃取-超高效液相色谱-线性离子阱串联质谱法直接测定水中10种藻类毒素

建立了全自动在线固相萃取-超高效液相色谱-线性离子阱串联质谱法直接测定水中10种藻类毒素的方法.利用程序实现多次进样,通过在线固相萃取对藻类毒素进行富集,然后切换六通阀,将富集的目标物冲洗至分析柱进行分离后,进入线性离子阱质谱检测.10种藻类毒素在相应的浓度范围内线性关系良好,相关系数均大于0.99,检出限在0.0015~0.0050μg/L之间,3个浓度水平(0.02、0.10和1.00μg/L)的加标回收率为83.7%~98.5%.结果表明,在线固相萃取极大简化了前处理过程,线性离子阱串联质谱法提高了痕量藻类毒素测定的灵敏度,增强子离子扫描(EPI)谱库的建立为藻类毒素的确证提供保障.本方法适用于水体中多种藻类毒素的快速确证和定量测定.     

固相支持液-液萃取/液相色谱-串联质谱法测定人全血中环孢素A

采用固相支持液-液萃取/液相色谱-串联质谱(LC-MS/MS)技术建立了人全血中环孢素A的分析方法。全血样品经蛋白沉淀后,上样至固相支持液-液萃取柱,经甲基叔丁基醚洗脱,Shim-pack XR-ODS色谱柱(75 mm×3. 0 mm i. d.,2. 2μm)分离,电喷雾电离源、正离子模式和多反应监测模式下采集数据,以环孢素D为内标物定量。结果表明,环孢素A在1. 5～500μg/L范围内呈良好的线性关系,相关系数(r)为0. 998,检出限和定量下限分别为0. 5μg/L和1. 5μg/L,在50、100、400μg/L 3个加标浓度下的平均回收率为78. 6%～83. 5%,日内和日间相对标准偏差(n=3)分别为3. 1%～5. 6%和4. 5%～8. 3%。该方法操作简便、灵敏度高,可用于全血中环孢素A的分析。     

固相萃取高效液相色谱-质谱法测定血浆中乙醇醛、甘油醛的含量

采用柱前衍生、固相萃取、高效液相色谱-质谱联用方法,建立了血浆中乙醇醛(GCO)、甘油醛(GCE)含量的测定方法。衍生试剂为3-m ethyl-2-benzoth iazolinone-hydrazone hydrochloride(MBTH);内标物为3-羟基丁醛;HPLC流动相为甲醇-醋酸铵(5 mmol/L),梯度洗脱;质谱电喷雾选择离子检测。比较了糖尿病大鼠和正常大鼠血浆中GCO、GCE的含量,正常大鼠血浆中GCO和GCE的含量分别为0.0574±0.0036μmol/L、0.0186±0.0019μmol/L;糖尿病大鼠血浆中GCO和GCE的含量分别为0.0763±0.0071μmol/L、0.0240±0.0023μmol/L,差异显著。     

固相萃取-高效液相色谱-串联质谱法同时测定银耳中的8种农药残留

建立了同时测定银耳中吡虫啉、啶虫脒、异丙威、丁硫克百威、克百威、甲胺磷、乙酰甲胺磷和咪鲜胺8种常见农药残留的固相萃取-高效液相色谱-串联质谱分析方法。5 g样品,加入1 g NaCl,用乙酸乙酯提取,提取液通过C18柱固相萃取净化后,以Phenomenex Luna C8色谱柱(150 mm×2.0 mm×3.0μm)分离,流动相A为含0.1%甲酸-5 mmol/L NH_4Ac溶液,流动相B为乙腈,梯度洗脱。质谱采用多反应监测(MRM)模式检测,外标法定量。结果显示:吡虫啉在1.0～1 000.0μg/L,啶虫脒、异丙威、丁硫克百威、克百威和咪鲜胺在1.0～500.0μg/L,甲胺磷和乙酰甲胺磷在1.0～250.0μg/L范围内线性良好,相关系数(r~2)均大于0.995;检出限为0.01～0.30μg/kg,定量限为0.03～1.00μg/kg。在低、中、高3个水平加标的回收率为70.1%～106.4%,相对标准偏差(RSD)为3.97%～13.68%。实际样品检测结果表明该方法稳定、准确、可靠。     

固相萃取净化/超高效液相色谱-串联质谱法测定养殖环境中地西泮及其代谢物

建立了固相萃取净化/超高效液相色谱-串联质谱(SPE/UPLC-MS/MS)同时测定养殖水和沉积物样品中地西泮及其3种代谢物的分析方法。水样经0.45μm玻璃纤维膜过滤,沉积物采用1%氨水-乙酸乙酯提取后,均通过混合型阳离子交换固相萃取(MCX SPE)柱富集净化。目标物用5%氨水-乙腈溶液洗脱后吹干,1 mL 40%乙腈水溶液溶解残渣,UPLC-MS/MS测定。经Phenomenex Kinetex C₁₈(100 mm×2.1 mm,1.7μm)色谱柱分离,乙腈和0.1%甲酸水溶液为流动相进行梯度洗脱。采用电喷雾正离子电离,多反应监测(MRM)模式下测定,内标法定量。4种目标物在0.1～100μg/L范围内的线性关系良好,相关系数(r²)大于0.999。水体和沉积物中的方法检出限分别为1.0～2.0 ng/L和0.02～0.05μg/kg,定量下限分别为2.0～5.0 ng/L和0.05～0.1μg/kg;平均加标回收率为90.2%～115%,相对标准偏差(RSD,n=6)为2.1%～9.6%。该方法灵敏度高,实用性强,可满足养殖环境中地...     

固相萃取-超高效液相色谱串联质谱法测定水中13种苯胺类化合物

建立了固相萃取-超高效液相色谱串联质谱法测定水中13种苯胺类化合物。样品通过HC-C₁₈固相萃取小柱富集，洗脱后加入内标苯胺-D5进行氮吹浓缩，经HSS T3色谱柱(150 mm×2.1 mm,1.8μm)分离，采用多反应监测扫描模式，以内标法定量。13种苯胺类化合物在0.1～100μg/L(其中3-硝基苯胺为0.2～200μg/L)范围内与特征离子的色谱峰面积线性关系良好，相关系数均大于0.995，方法检出限为0.001～0.006μg/L，平均加标回收率为67.3%～117%，测定结果的相对标准偏差为3.77%～16.9%(n=6)。该法操作简单、稳定性好，能够满足实际水体中13种苯胺类化合物大批量样品分析的需求。     

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.     

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.     

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...