气相色谱-电子捕获法测定血浆中的雷公藤甲素

 血浆样品经碱化后用乙醚 氯仿 (体积比为 3∶1)混合液提取 ,浓缩的提取物与三氟醋酐进行衍生化反应 ,用气相色谱法分离、63Ni电子捕获检测器测定雷公藤甲素的含量。色谱柱为SE 5 430m× 0 2 5mmi d 交联石英毛细管柱。雷公藤甲素的质量浓度在 1 0 μg/L～ 5 0 0 μg/L范围内与峰面积线性关系良好 (r =0 9990 ) ,在血浆中的平均回收率为 96 3% ,最小检测限为 0 5 μg/L。方法重现性好 ,准确、灵敏 ,无杂质干扰 ,数据准确可靠 ,可用于临床生物样品中雷公藤甲素含量的测定。     

高效液相色谱梯度法测定雷公藤制剂中雷公藤甲素的含量

采用高效液相色谱梯度法分离测定雷公藤制剂中雷公藤甲素的含量,用国产YWG色谱柱分离,二极管阵列检测器检测,所得三维光谱与空白光谱进行差减,取波长218nm处色谱图积分,定量。与等度法比较,梯度法具有更高的分离度、灵敏度,测定雷公藤口服液中雷公藤甲素的质量浓度为202．0μg／L,每片雷公藤片剂含甲素11．74μg,结果显著低于等度法和标示量（P<0．05）。     

高效液相色谱-质谱法测定尿液中痕量雷公藤春碱

提出了尿液中雷公藤春碱的高效液相色谱-质谱测定方法。尿液样品经Waters Oasis(MCX固相萃取小柱富集、净化后,以Zorbax Eclipse SB C18反相色谱柱(4.6 mm×250 mm,5μm)为分离柱,以乙酸盐缓冲溶液-乙腈(40+60)为流动相,采用正离子模式大气压化学电离源,在选择离子监测模式下进行检测,雷公藤春碱的定量离子质荷比(m/z)为874.4。线性范围为0.2~50.0μg·L-1,检出限(3S/N)为0.07μg·L-1,测定下限(10S/N)为0.2μg·L-1。回收率在86.0%~92.0%之间,日内(n=6)和日间(n=15)相对标准偏差分别小于7.5%和10.5%。     

反相高效液相色谱测定雷公藤浸膏中甲素的含量

报道了液固萃取-反相高效液相色谱法测定雷公藤浸膏(乙酸乙酯提取物)中甲素含量的方法。用LichrospherC18色谱柱，以甲醇：水-60：40(V／V)溶液为流动相，检测波长218nm。方法回收率为99．4％，变异系数为0．53％，方法快速，重现性及准确度能满足雷公藤浸膏中甲素含量测定的要求。     

RP-HPLC测定雷公藤甲素聚乳酸纳米粒的包封率及载药量

本文研究了反相高效液相色谱和超速冷冻离心测定雷公藤甲素聚乳酸纳米粒包封率和载药量的方法。实验结果表明,在优化色谱条件下雷公藤甲素与辅料及溶剂峰分离良好,雷公藤甲素在1.84～46μg·mL-1范围内本法有良好的线性关系(r=1.0,n=6),方法日内及日间精密度分别为0.09%～1.01%及0.5%～2.12%,在空白聚乳酸纳米粒中雷公藤甲素的加样回收率为98.85%～100.48%,聚乳酸包裹的雷公藤甲素纳米粒的包封率分别为74.27%、60.37%、46.6%,其相对应的载药量分别为1.36%、1.95%、2.57%。此方法准确可靠、简单、重现性好。     

高效液相色谱-串联质谱法同时测定葛根中葛根素和大豆苷元

提出了高效液相色谱-串联质谱法测定葛根中葛根素和大豆苷元的含量。样品经乙醇提取,所得提取液用乙醇定容至100mL后经Waters Xterra MS C18色谱柱(150mm×3.9mm,5μm)分离,用乙腈与50mmol.L-1甲酸溶液(40+60)的混合液洗脱,采用电喷雾正离子电离多反应监测模式。葛根素和大豆苷元的质量浓度分别在0.050～0.50mg.L-1和5.0～50mg.L-1之间与峰面积呈线性关系,检出限(3S/N)均为5μg.L-1。在0.1,1.0,10.0mg.L-1 3个浓度水平进行加标回收试验,葛根素和大豆苷元的回收率分别为96.6%和97.4%。     

凝胶渗透色谱-超高效液相色谱-串联质谱法测定水产品中甲基睾酮含量

提出了水产品中甲基睾酮的超高效液相色谱-串联质谱法分析方法。样品经叔丁基甲醚提取,提取液经凝胶渗透色谱和HLB固相萃取柱净化,所得洗脱液40℃氮吹挥干后用流动相溶解,用ACQUITY UPLC BEH C18色谱柱分离,以乙腈-0.2%甲酸(40+60)溶液为流动相洗脱,采用电喷雾正离子源及多反应监测模式测定。甲基睾酮的质量浓度在0.50～100μg.L-1范围内呈线性关系,测定下限(10S/N)为0.5μg.kg-1。添加1.0,5.0,10.0μg.kg-1 3个浓度水平进行加标回收试验,回收率在87.0%～94.2%之间,测定值的相对标准偏差(n=5)均小于6%。     

反相高效液相色谱同时测定五味子中五味子醇甲、五味子酯甲和五味子乙素的含量

本文建立了同时测定五味子中五味子醇甲、五味子酯甲和五味子乙素的反相高效液相色谱(RP-HPLC)方法。五味子先经超声提取后用高效液相色谱法测定。色谱柱为Kromasil C18柱(150×4.6 mm,5μm),流动相为甲醇-水(75∶25,V/V),紫外检测波长220 nm,柱温30℃,流速1.0 mL/min。结果显示,五味子醇甲在0.10~6.0μg范围内(r=0.9998),五味子酯甲在0.13~8.0μg范围内(r=0.9999),五味子乙素在0.03~2.0μg范围内(r=0.9999)线性关系良好。平均回收率五味子醇甲为98.6%,相对标准偏差(RSD)为1.4%(n=5);五味子酯甲为97.1%,RSD为1.6%(n=5);五味子乙素为97.7%,RSD为1.1%(n=5)。本法准确、快速、灵敏度高,可用于五味子中有效成分的定量分析。     

高效液相色谱-电感耦合等离子体质谱法测定饮用水中碘酸根和碘离子

提出了高效液相色谱-电感耦合等离子体质谱法测定饮用水中碘酸根和碘离子的方法。饮用水样品通过Dionex IonPac AS14阴离子交换柱及AG14保护柱分离碘酸根和碘离子,用50mmol.L-1碳酸铵溶液(用氨水调至pH 9.9)作流动相进行淋洗。于洗脱液中用电感耦合等离子体质谱法分别测定碘酸根和碘离子的含量,两者的线性范围均为0.20～300μg.L-1,检出限(3S/N)依次为0.09μg.L-1和0.13μg.L-1。以饮用水为基体加入两个不同浓度水平的标准溶液按方法分析后,求得方法的回收率及精密度为①碘酸根回收率在100.5%～113.0%,相对标准偏差(n=8)在1.2%～2.8%之间;②碘离子回收率在101.9%～110.7%,相对标准偏差(n=8)在1.3%～2.0%之间。     

液相色谱-串联质谱法测定葡萄酒中7种生物胺含量

提出了液相色谱-串联质谱法测定葡萄酒中2-苯乙胺、色胺、尸胺、组胺、腐胺、精胺、亚精胺等7种生物胺含量的方法。样品经0.45μm滤膜过滤后,直接通过Zorbax Eclipse XDB C8色谱柱(4.6mm×150mm,5μm)进行分离,以不同体积5mmol·L-1乙酸铵-10mmol·L-1全氟己酸甲醇溶液(A)和5mmol·L-1乙酸铵-10mmol·L-1全氟己酸水溶液(B)的混合液为流动相梯度洗脱,串联质谱法进行测定。7种生物胺的质量浓度均在0.1～5.0mg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)在0.005～0.02mg·L-1之间。以空白葡萄酒样品为基体进行加标回收试验,测得回收率在84.1%～97.5%之间;测定值的相对标准偏差(n=5)在6.3%～13%之间。     

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.     

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).     

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.