流动注射在线萃取—火争原子吸收法测定食用盐中的锌

基于锌与1-（2-吡啶偶氮）-2-萘酚（简称PAN）形成的配合物可被氯仿萃取，从高盐基体样品中分离富集锌，利用自行设计的分相器，实验确定了最佳的流动注射在线萃取-火焰原子吸收光度法测定锌的流呼系统和化学反应条件。在选定的工作条件下，其RSD和检出限分别为4.3%（c=0.6μg/mL，n=11)和0.03μg/mL，测定速度为25样/h。用于实际样品的测定，加标回收率为97%-106%。     

分散液-液微萃取/高效液相色谱法测定水样中的痕量双酚A

建立了分散液-液微萃取与高效液相色谱联用技术测定水样中痕量双酚A(BPA)的方法. 通过对实验条件的筛选及优化, 得到最佳条件: 22.5 μL氯苯作萃取剂、0.5 mL丙酮作分散剂、0 min静止萃取时间、调节pH 3.2左右、10%离子强度及9 mL水样体积. 此条件下方法的线性范围为0.5~100 μg/L(R2=0.9941), 检出限为0.10 μg/L. 在BPA质量浓度为1 μg/L条件下, 方法回收率为87.8%~111.0%, 相对标准偏差8.3%(n=5), 富集倍数范围1905~2527. 对添加不同BPA浓度的自来水、地表水及回用中水进行分析, 回收率分别为(108±11.1)%, (107±13.2)%及(81.2±6.2)%(n=3). 在既定的色谱条件下, BPA的测定不受乙炔基雌二醇、雌二醇、雌三醇、雌酮和壬基酚等雌激素的干扰.     

聚酰亚胺液晶定向膜(IP-300B)中微量钠的测定

应用原子吸收光谱法测定聚酰亚胺液晶定向膜 (IP -30 0B)中的微量钠。样品经硫酸消化 -炭化 ,再经马福炉灰化后 ,溶液上机测定。结果表明 ,钠的浓度与吸光度的线性关系 ( 0 1 0～ 2 0 0 μg/mL)、特征浓度 ( 3 5× 1 0 - 3 μg/mL/1 % )、精度 (S :0 0 0 6 8;CV % :3 0 )、和标准添加回收率 ( 92 3%～ 1 0 6 2 % )均达到要求 ,为液晶印刷电路板生产建立质控方法。     

火焰原子吸收法测定空气与废气中的铅(铅尘和铅烟)

采用火焰原子吸收法监测空气与废气中气溶胶样品的铅尘和铅烟 ,依照有关部门已制订的一批统一 (或推荐 )的监测方法资料 ,通过自身一系列的方法适用性检验 ,经外场的采样效率试验直至实验室内的空白值、酸度及样品基体干扰影响和消除的尝试 ,加以改变仪器工作条件比对和回收试验等 ,使实测样品获得了满意结果。铅的方法检出限为 0 0 5 μg/mL/ 1 %吸收 ,测定下限为 0 1 5 μg/mL ,线性范围 0 5～ 1 0 0 μg/mL ,测定范围 :0 0 5～ 5 0mg/m3 ,当采样体积为 5 0m3 ,取 1 / 2张滤膜 (直径 8～ 1 0cm)进行铅尘测定时气溶胶中铅的最低检出浓度为 2× 1 0 - 4mg/m3 ,采样效率为 98% ,样品回收率为 92 3%。     

高效液相色谱法测定人血浆中奥氮平的浓度

 用高效液相色谱法测定了人血浆中奥氮平的浓度。色谱条件 :采用岛津LC 6A型高效液相色谱仪 ;色谱柱为ZorbaxODS (15 0mm× 4 6mmi d ,粒径 5 μm) ;流动相为V(5 0mmol/L磷酸钠缓冲液 ,pH 7 2 )∶V(甲醇 )∶V(乙腈 ) =12∶10∶3的溶液 ;检测波长为 2 70nm ;流速为 1 0mL/min ;柱温 40℃ ;灵敏度 0 0 0 5AUFS ;纸速 2mm/min。实验结果显示 ,在上述条件下 ,该方法的线性范围为 15 μg/L～ 12 0 0 μg/L(r =0 9988) ,最低检测限为 3μg/L ,血浆中奥氮平的平均回收率为 (97 0 2± 3 11) % ,测定结果的日内平均相对偏差为 3 86 % (n =15 ) 。     

气相色谱-质谱法检测益智药材中16种多环芳烃

建立了气相色谱-质谱联用技术同时测定益智药材中16种多环芳烃(PAHs)的分析方法。最佳萃取条件为：取样品2.0 g,加入同位素内标后用无水乙醇、水混合溶解,以10 mL正己烷提取;提取液先过Florisil柱固相萃取,经氢氧化钾-乙醇溶液皂化,多环芳烃分子印迹柱固相萃取后,以5 mL二氯甲烷-正己烷(1∶1,体积比)进行洗脱;采用DB-EUPAH毛细管色谱柱进行分离,内标标准曲线法定量测定。在此条件下,16种多环芳烃的线性范围为1.0~200.0 μg/L(r2 ≥ 0.992 5);检出限(S/N=3)为0.3~1.0 μg/kg;在不同浓度(1、3、10 μg/kg)基质加标条件下,苯并［c］芴(BcFL)的加标回收率为65.4%~72.8%,日内相对标准偏差(RSD,n=6)为6.0%~7.4%,日间RSD(n=6)为8.5%;其他15种多环芳烃的加标回收率为89.3%~116%,日内RSD(n=6)为0.10%~6.1%,日间RSD(n=6)为1.2%~7.5%。该方法的前处理净化效果好、灵敏度高、准确度高,适用于益智药材中16种多环芳烃的定量检测。     

东莞市儿童血清中5种微量元素及钙含量的分析研究

测定了东莞市 1 3 89名儿童血清中锌 (Zn)、铁 (Fe)、铜 (Cu)、锰 (Mn)、铅 (Pb)及钙 (Ca)含量。结果分别为Zn (0 973± 0 2 3 8) μg/mL、Fe (1 1 0 1± 0 2 41 ) μg/mL、Cu (0 90 5±0 2 1 3 ) μg/mL、Mn (0 0 3 9± 0 0 2 0 ) μg/mL、Pb (0 0 5 3± 0 0 1 5 ) μg/mL及Ca (85 2 5 2± 1 4 795 )μg/mL,男女间没有显著差异。     

聚乙二醇萃取—络天青S光度法测定原油及润滑油中的铝

以聚乙二醇 -硫酸铵 -铝试剂体系萃取分离干扰离子 ,采用络天青 (CAS) -溴化十六烷基三甲基胺 (CTMAB)为显色体系测定原油中的铝。试验了测定条件及萃取分离干扰离子的条件。测定范围在 0～ 1 0 μg/ 2 5ml,ε64 5nm=4.95× 1 0 4 L· mol-1· cm-1,合成样品回收率为 97.3%～1 0 2 .7% ,原油分析结果的相对标准偏差≤ 2 .6%。该方法灵敏简便 ,整个萃取操作具有安全、无毒、快速的优点。     

微柱高效液相色谱法测定环境样品中的铁、钴、镍、铜、锌、锰

研究了用 2-(2-喹啉偶氮 )-间苯二酚 (QAR)为柱前衍生试剂 ,以WatersXterraTM RP18(1 .0×5 0mm ,2. 5 μm)微柱为固定相 ,60 %的甲醇 (内含 0 . 5 %的醋酸 )为流动相 ,高效液相色谱分离、二极管矩阵检测器测定铁、钴、镍、铜、锌和锰的方法。根据信噪比 (S N =3 )得各金属离子的检测限分别为 :铁3 μg L、钴 4μg L、镍 2 μg L、铜 4μg L、锌 5 μg L、锰 8μg L ,方法用于环境样品中痕量铁、钴、镍、铜、锌、锰的测定 ,相对标准偏差在 1 . 6%～ 3 . 5 %之间 ,标准回收率为 93 %～ 1 0 7%。     

超高效液相色谱-串联质谱法同时测定食品中碱性橙、碱性嫩黄O和碱性桃红T

本文建立了同时测定食品中碱性橙、碱性嫩黄O和碱性桃红的超高效液相色谱-串联质谱(UPLC-MS/MS)检测方法.样品经碱化甲醇提取、二氯甲烷萃取、浓缩、酸化甲醇溶解和甲醇饱和正己烷溶液萃取净化后进行测定.本方法检出限分别为碱性橙0.6 μg/kg、碱性嫩黄O 0.3 μg/kg、碱性桃红T 0.7 μg/kg.六种食品样品的回收率为72.1%～91.1%,相对标准偏差(RSD)为2.4%～9.1%(n=6),三种染料在0.01～0.5 μg/mL范围内呈良好的线性关系,线性回归系数r均大于0.9950.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.