LTQ-Orbitrap组合式高分辨质谱法快速筛查毛发中7种毒品及代谢物

采用超高压液相色谱-二维线性离子阱结合静电场轨道阱组合式高分辨质谱联用技术(Accela U HPLC/LTQ Orbitrap XL),建立了人毛发中吗啡、O~6-单乙酰吗啡、可待因、乙酰可待因、氯胺酮、去甲氯胺酮和美沙酮毒品及代谢物快速筛查方法。取毛发样品经表层清洗后冷冻研磨粉碎,置于硼酸盐缓冲液(pH 9.2)中超声90 min,离心取上清液,用Oasis HLB柱固相萃取制备。通过静电场轨道阱全扫描得到毒品及其代谢物的精确相对分子质量,同时进行7种毒品及其代谢物的快速筛查。高分辨率质谱可有效去除毛发基质干扰,毒品及其代谢物筛查检出限在0.001～0.02 ng/mg,在0.05～50 ng/mg范围内存在良好线性关系(r>0.9975);本方法平均加标回收率为76.1%～109.6%;日内及日间精密度RSD≤14.9%。本方法灵敏度高,样品制备简便,适用于常见毒品的快速筛查。     

超高效液相色谱-串联质谱结合内标法快速检测毛发中15种毒品及代谢物

建立了毛发中15种毒品及其代谢物的超高效液相色谱-串联质谱(UPLC-MS/MS)快速确证与内标定量分析方法。向洗净的毛发样品中加入甲醇研磨提取,研磨液经过滤后,以5 mmol/L NH_4Ac-0.1%甲酸水溶液及甲醇作为流动相,经Phenomenex Kinetex Biphenyl色谱柱(100 mm×3.0 mm, 2.6μm)分离,采用分段多反应监测(sMRM)-信息依赖性采集(IDA)-增强离子扫描(EPI)模式,结合EPI谱库检索确证定性结果,运用内标法定量分析。毛发中15种毒品及代谢物在0.05～5.0 ng/mg质量浓度范围内线性相关系数均大于0.995;各化合物检出限范围为0.5～10 ng/g;低、中、高浓度的加标回收率为89.2%～117.5%;相对标准偏差为1.5%～7.1%。     

Determination of digoxin and its metabolites in biological samples by solidphase supported liquid-liquid extraction-liquid chromatography-tandem mass spectrometryEI北大核心CSCD

采用固相支撑液液萃取-超高效液相色谱-串联质谱（SLE-UPLC-MS/MS）技术建立了生物样本血液、尿液和肝组织中地高辛（DG）及其3种代谢物的分析方法。生物样本经匀浆、蛋白沉淀后,通过含有硅藻土的固相支撑液液萃取（SLE）柱净化富集,经洗脱、定容后进行LC-MS/MS分析。结果表明,血液基质中,地高辛在0.1～100 ng/mL浓度范围内线性关系良好;肝脏和尿液基质中,地高辛在0.2～100 ng/mL浓度范围内线性关系良好,地高辛的3种代谢物在0.5～100 ng/mL浓度范围内线性关系良好,3个浓度水平（10, 50和100 ng/mL）的加标回收率为60.5%～95.6%,基质效应80.7%～113.6%,日内、日间相对标准偏差（RSD）均小于13%,检出限为0.1～0.5 ng/mL。所建立的方法可用于生物样本中地高辛及其代谢物的定性定量分析。     

超声提取-超高效液相色谱-串联质谱法测定毛发中常见毒品及代谢物的含量

建立了超声提取-超高效液相色谱-串联质谱法（UHPLC-MS/MS）测定毛发中常见毒品及代谢物含量的方法。称取洗涤（水、二氯甲烷、丙酮依次振荡洗涤各1次）并晾干后的毛发样品40～60 mg,将其剪成约1 mm小段,加入3.2 mm的破碎珠6颗,冷冻破碎5 min;再称取破碎后的毛发样品20 mg,加入1 mL甲醇,于0℃冰水浴中超声提取20 min,上清液用0.25μm有机滤膜过滤,滤液供UHPLC-MS/MS测定。结果显示：O⁶-单乙酰吗啡（6-AM）、吗啡（MOR）、氯胺酮（K粉）、甲基苯丙胺（MAMP）、苯丙胺（AMP）、可卡因（COC）、苯甲酰爱康宁（BZE）、3,4-亚甲双氧甲基苯丙胺（MDMA）、3,4-亚甲双氧苯丙胺（MDA）、3,4-亚甲双氧乙基苯丙胺（MDEA）、可待因（COD）、去甲氯胺酮（NK）、Δ⁹-四氢大麻酚（THC）、大麻二酚（CBD）、大麻酚（CBN）等15种目标物的质量分数在一定范围内与其对应的峰面积呈线性关系,BZE、THC、CBD、COC、CBN的检出限（3S/N）均为0.001 ng·mg^-1<...     

超临界二氧化碳萃取结合高效液相色谱-串联质谱法测定毛发中11种常见精神药物

建立了一种超临界二氧化碳萃取(SFE)结合高效液相色谱-串联质谱(HPLC-MS/MS)测定毛发中11种常见精神药物的方法,并应用于实际毛发样品的检测。剪碎的毛发样品在优化的SFE条件下萃取,提取液经氮吹浓缩,以甲醇定容至100μL后,进行HPLC-MS/MS测定。结果表明,11种常见精神药物在2～200 ng/mL范围内线性良好,相关系数(r~2)大于0.999,方法检出限为0.01～0.05 ng/mg,定量下限为0.03～0.10 ng/mg;在0.05、0.20、0.40 ng/mg加标水平下,方法的回收率为81.6%～94.8%,相对标准偏差(RSD)为0.50%～3.4%。该方法快速、灵敏、准确,可用于毛发中11种常见精神药物的同时检测。     

超高效液相色谱-串联质谱法测定医用口罩中有机磷酸酯

该研究优化了医用口罩样本中16种有机磷酸酯（OPEs）的萃取和净化前处理过程,建立了超高效液相色谱－串联质谱（UPLC－MS/MS）测定方法。样本经甲醇超声萃取后,采用ENVI－18固相萃取小柱净化,最终使用Acquity UPLC BEH C18色谱柱以5 mmol/L乙酸铵缓冲溶液－甲醇为流动相进行分离,采用UPLC－MS/MS测定,内标法定量。结果表明,16种OPEs在0.1～50 μg/L质量浓度范围内呈良好的线性关系（r > 0.995）,方法检出限为0.004 60～1.03 ng/dm2,定量下限为0.015 2～3.43 ng/dm2,加标回收率为68.8%～140%,相对标准偏差为0.70%～18%。采用所建立的方法对42个医用口罩中16种OPEs进行测定,其总浓度为6.60～2 387 ng/dm2,其中12种OPEs的检出率高于50%,表明这些OPEs在医用口罩中普遍存在。磷酸三苯酯（TPHP）和磷酸三（1-氯-2-丙基）酯（TCIPP）为主要的OPEs,浓度分别为0.131～2 274 ng/dm2和0.370～79.8 ng/dm2。整体上OPEs的浓度均较低,推测口罩样本中的OPEs可能是生产和包装过程中受空气或塑料包装污染所致。     

QuEChERS分散固相萃取—气相色谱—负化学电离质谱法测定植物油中氟虫腈及其代谢物残留

建立了基于QuEChERS分散固相萃取(dSPE)气相色谱-负化学电离质谱(GC-NCI/MS)测定植物油中氟虫腈及其代谢物残留的分析方法。样品经乙腈提取，QuEChERS dSPE EMR-Lipid萃取净化，分取净化液浓缩至近干，正己烷复溶，GC-NCI/MS检测。GC-NCI/MS分析方法用氦气作为载气，流速设为1 mL/min;反应气为甲烷，气体流量40%;采用Agilent DB-5MS色谱柱进行分离，升温程序：初始温度设置40℃,保持1 min,以30℃/min升温至200℃,然后以15℃/min升到300℃,维持3 min,选择离子监测(SIM)检测，基质匹配外标法定量。在玉米油、橄榄油、菜籽油、大豆油、花生油这5种基质中，氟虫腈及其代谢物在质量浓度0.5～25 ng/mL范围与其对应的峰面积之间线性关系良好，相关系数R²均大于0.994,在0.002、0.004和0.02 mg/kg 3个添加水平下，氟虫腈及其代谢物的平均回收率在95%～115%之间，相对标准偏差在0.36%～8.40%之间。方法灵敏度、准确度和精密度均符合氟虫腈及其代谢物残留检测...     

在线固相萃取-高效液相色谱法同时测定人尿液中7种多环芳烃代谢物

采用双三元液相色谱系统结合荧光检测器,建立了在线固相萃取-液相色谱法同时测定人尿液中7种多环芳烃代谢物的方法。目标化合物首先在Turboflow Cyclone固相萃取柱上在线富集浓缩,然后通过六通阀转移至Hypersil Green PAH色谱柱,以乙腈-水为流动相进行梯度洗脱分离,流速1.0 mL/min,柱温30℃,荧光检测器检测,分离周期为20 min。在优化的色谱条件下,5~2000 ng/L或50~20000 ng/L范围内,7种多环芳烃代谢物均呈良好的线性关系(r≥0.999),方法检出限为0.5~15 ng/L,加标回收率为80.7％~110.7％。应用本方法对吸烟和非吸烟人群尿液中7种多环芳烃代谢物的含量进行了测定,吸烟者尿液中的2-羟基萘、1-羟基萘、2-羟基菲、2-羟基芴、4-羟基菲、6-羟基显著高于非吸烟者。     

LC-MS/MS法快速分析不同吸烟量人体唾液尼古丁及其代谢物水平

采用Salivette采样管收集人体唾液,以氘代尼古丁、氘代可的宁以及3-羟基-氘代可的宁为内标,在LC-MS/MS的大气压化学电离(APCI)离子化模式下,建立了同时测定吸烟者唾液中尼古丁及其代谢物的分析方法。该法前处理简单,色谱运行时间不足1 min,尼古丁及其代谢产物的加标回收率为94%～104%,相对标准偏差为0.29%～4.0%,线性相关系数均大于0.998。对不同吸烟量志愿者的唾液样本进行了分析,并根据唾液中尼古丁及其代谢物的含量总和,使用ada-boost算法对不同吸烟量进行分类预测,准确度可达76%。实验结果表明,可的宁在唾液与血液(r=0.92)、唾液与尿液(r=0.84)中的浓度均具有一定的相关性,且半衰期较长,适合作为评估烟气暴露程度以及尼古丁摄入量的生化指标。     

超声辅助衍生-液相色谱/串联质谱法快速测定养殖水体中硝基呋喃类代谢物的残留量

建立了超声辅助衍生结合液相色谱/串联质谱(UAD-LC-MS/MS)快速测定水产养殖水体中4种硝基呋喃代谢物的方法。实验对比了超声辅助衍生和传统振荡衍生的效果,优化了色谱质谱条件以及衍生时间。水样经超声辅助的方式衍生,以2-硝基苯甲醛为衍生化试剂,再经乙酸乙酯提取,在正离子模式下以电喷雾电离串联质谱进行测定,内标法定量。在优化的实验条件下,4种代谢物在0.5~50 ng/m L范围内线性良好,相关系数0.998,方法检出限为0.02 ng/m L,定量限为0.05 ng/m L。在0.1,0.5和5 ng/m L的添加水平下,4种代谢物的平均回收率处于91.9%~104%之间,相对标准偏差(RSDs)处于2.1%~8.1%之间。测定了12份养殖水体中4种硝基呋喃代谢物的残留量,其中2份样本中检出呋喃西林代谢物氨基脲。方法可以准确测定养殖水体中硝基呋喃代谢物的残留量。     

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...     

Hard and soft acids and bases: structure and process

Under investigation is the structure and process that gives rise to hard-soft behavior in simple anionic atomic bases. That for simple atomic bases the chemical hardness is expected to be the only extrinsic component of acid-base strength, has been substantiated in the current study. A thermochemically based operational scale of chemical hardness was used to identify the structure within anionic atomic bases that is responsible for chemical hardness. The base's responding electrons have been identified as the structure, and the relaxation that occurs during charge transfer has been identified as the process giving rise to hard-soft behavior. This is in contrast the commonly accepted explanations that attribute hard-soft behavior to varying degrees of electrostatic and covalent contributions to the acid-base interaction. The ability of the atomic ion's responding electrons to cause hard-soft behavior has been assessed by examining the correlation of the estimated relaxation energies of the responding electrons with the operational chemical hardness. It has been demonstrated that the responding electrons are able to give rise to hard-soft behavior in simple anionic bases.     

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).