高效液相色谱法测定马来酸麦角新碱注射液中甲硫氨酸

建立高效液相色谱法测定马来酸麦角新碱注射液中甲硫氨酸含量的方法。采用Venusil HILIC色谱柱（250 mm×4.6 mm, 5μm），以5 mmol/L磷酸氢二钾溶液（用磷酸调节pH值至6.9）-乙腈（体积比为20∶80）为流动相，流量为1.0 mL/min，柱温为30℃，检测波长为215 nm。结果表明，甲硫氨酸质量浓度在20～400μg/mL范围内与色谱峰面积的线性关系良好，相关系数为0.999 9，检出限和定量限分别为0.5、1.6μg/mL，平均加标回收率为99.7%，测定结果的相对标准偏差为0.3%(n=6)。该方法适用于测定马来酸麦角新碱注射液中甲硫氨酸的含量。     

固相微萃取-气相色谱联用技术测定水相中的邻苯二甲酸二(2-乙基)己酯

利用顶空固相微萃取与气相色谱联用技术（HS－SPME－GC）以富勒烯聚二甲基硅氧烷（PSO－C60）固定相处制萃取头分析了塑料浸取液中的邻苯二甲酸二（2－乙基）己酯（DEHP），并对萃取温度、离子强度、吸附时间和热解析时间进行了研究。结果显示，该方法的线性范围在5μg/L－500μg/L，检测出了为2．8μg/L，相对标准偏差为4．8％（n=6).     

纳米TiO2分离富集和ICP-AES测定地质样品中的钼和钨

本文以ICP－AES为检测手段，系统地研究了纳米TiO2材料对钼酸根和钨酸根离的分离／富集行为及影响其吸附和解脱的主要因素，并考察了共存离子的干扰影响，在优化的实验条件下，本法测定Mo(Ⅵ）和W(Ⅵ）的检出限分别为0.017μg/mL和0.044μg/mL，相对标准偏差（RSD）为1.8%（对Mo）和2.3%（对W）（n＝9，c=5.0μg/mL）。本法已应用于水系沉积物和岩矿标准样品中Mo或W的测定，测定值与标准值基本吻合。     

离子色谱法测定依达拉奉注射液中亚硫酸盐

建立测定依达拉奉注射液中亚硫酸根离子含量的离子色谱法。采用IonPac AS11-HC阴离子分析柱（250mm×4.6 mm,7.5μm），柱温为25℃，以15 mmol/L氢氧化钾溶液作为淋洗液，流量为1.0 mL/min，检测器为电导检测器，检测器温度30℃，抑制器为自动再生抑制模式，抑制电流40 mA，进样体积为25μL，用离子色谱法测定亚硫酸盐，硫酸根离子质量浓度在0.1～200μg/mL范围内与色谱峰面积线性关系良好，相关系数为0.999 8。该方法检出限为0.027μg/mL，定量限为0.072μg/mL。亚硫酸根离子在水溶液中8 h内稳定。样品加标回收率为98.5%～100.6%，相对标准偏差为0.7%(n=9)。该方法操作简单，专属性强，灵敏度高，重复性好，可用于依达拉奉注射液中亚硫酸盐含量的测定。     

超高效液相色谱-四极杆/静电场轨道阱质谱测定猪尿中环丙氨嗪及其代谢物残留量

建立了超高效液相色谱－四极杆/静电场轨道阱质谱（UHPLC－Quadrupole－Orbitrap MS）检测猪尿中环丙氨嗪及其代谢物三聚氰胺的方法。样品用1%三氯乙酸超声提取,调节pH < 3.0,阳离子交换固相萃取柱净化氮气吹干后,95%乙腈水溶液复溶,经Syncronis HILIC色谱柱（100 mm × 2.1 mm,1.7 μm）分离,10 mmol/L乙酸铵水溶液－乙腈为流动相梯度洗脱,使用电喷雾离子源在平行反应监测模式（PRM）下检测。环丙氨嗪采用外标法定量,三聚氰胺采用内标法定量。对比了PRM模式与三重四极杆质谱的多反应监测模式（MRM）,结果显示两者具有相当的定量能力,但PRM模式根据目标化合物及其二级子离子的精确质量数和丰度比进行定性分析,具有较强的定性优势。最佳条件下,2种目标物均在0.2～50.0 ng/mL范围内线性关系良好（r2 > 0.99）,定量下限均为1.0 μg/kg。在1.0、2.0、150.0 μg/kg加标水平下,回收率为78.0%～105%,相对标准偏差（RSD）不大于11%。该方法可同时准确测定猪尿中环丙氨嗪和三聚氰胺的残留量。     

液相色谱-串联质谱法测定食品接触材料及制品中新戊二醇迁移量

采用液相色谱－串联质谱（LC－MS/MS）建立了食品接触材料及制品中新戊二醇的测定方法。样品采 用水、4%（体积分数,下同）乙酸、10%乙醇、20%乙醇、50%乙醇、95%乙醇和橄榄油作为食品模拟物进行 迁移试验后,水、4%乙酸、10%乙醇浸泡液直接过滤进样,其他乙醇类模拟物浸泡液采用氮吹方式去除大部 分乙醇后重新用水定容,橄榄油浸泡液采用 10% 乙醇萃取。经处理后的试液采用 ACQUITY UPLC? BEH C18 （50 mm × 2. 1 mm,1. 7 μm）色谱柱,以0. 01%甲酸溶液－乙腈为流动相进行梯度洗脱,在电喷雾离子源正离 子（ESI+ ）多反应监测（MRM）模式下进行检测,外标法定量。在优化条件下,新戊二醇在10～100 μg/L（μg/kg） 范围内线性关系良好,相关系数大于 0. 999。在 10、20、100 μg/L（μg/kg）3 个加标水平下,方法回收率为 92. 8%～117%,相对标准偏差（RSD）为0. 90%～8. 6%,检出限（LOD,S/N ≥ 3）为5 μg/L（μg/kg）,定量下限（LOQ, S/N ≥ 10）为10 μg/L（μg/kg）。该方法具有前处理简单易行、灵敏度高、稳定可靠的优点,涉及的食品模拟物 基本包括相关法规和标准中规定的类型,方法LOD和LOQ均低于相关法规和标准中的限量要求,能够满足食 品接触材料及制品中新戊二醇迁移量的检测需求,为相关产品监管和质量控制提供了可靠的技术手段。     

微乳液介质—1—（2—吡啶偶氮）—2—萘酚光度法测定汽油中环烷酸铁的含量

本研究了微乳液为介质时，铁与１－（２－吡啶偶氮）－２－萘酚（ＰＡＮ）的显色反应。选择７３０ｎｍ处为测定波长，ε为１．４×１０＾４Ｌ．ｍｏｌ＾－＾１．ｃｍ＾－＾１，铁量在０－５０μｇ／２５ｍｌ范围内符合比耳定律，该法适用于汽油中环烷酸铁的测定。     

阻抑聚丙烯酰胺催化蛋白质-亚甲基蓝褪色光度法测定痕量铋

在加热条件下，基于Bi（Ⅲ）对聚丙烯酰胺（PAM）催化蛋白－亚甲基蓝（MB）褪色反应有强的抑制作用，建立了动力学光度法测定铋的新方法。△A与CBi(Ⅲ）呈线性关系的范围为0．08－0．48μg/L；检出限为0．004μg/L；对0．04和0．040μgBi(Ⅲ）／L测定的RSD分别为6．4％一2．6％，本阻抑－催化褪色反应对Bi(Ⅲ）、蛋白质－亚甲基蓝和PAM为一级反应，表观活化能为49．22kJ/mol.该方法已用于某些谷物，人发和水样中Bi(Ⅲ）的测定。结果满意。     

高效液相色谱法测定人尿中神经鞘氨醇和二氢神经鞘氨醇

建立了一种检测人尿中神经鞘氨醇（So）和二氢神经鞘氨醇（Sa）的高效液相色谱方法（HPLC）。离心分离尿样中的片状剥落细胞,裂解后用乙酸乙酯萃取、邻苯二甲醛衍生,在HPLC系统中通过梯度洗脱用Nova-PakC18－RP色谱柱（15cm×3．9mm,4μm）分离、荧光检测器检测。So和Sa的检出限均为0．05ng（女性尿样0,075μg/L、男性尿样0．005μg/L）。分析从我国一个村在采集的40份尿样,女性尿样中So、Sa和Sa／So比值分别为1．29－13．58μg/L、0．25－3．13μg/L和0．15－0．25,男性尿样中分别为0．075~3．07μg/L、0.019－0．50μg/L和0．028～0．26。     

流动注射冷蒸气发生法测定环境样品中痕量汞

以气体扩散膜为分离装置，流动注射进样冷蒸气发生法测定了土壤中的汞。试验了载流种类，流速，浓度，还原剂的浓度，流速，载气及春流速等分析参数对测定的影响。实验中观察到Cr(Ⅵ）对汞的响应信号有负干扰。方法的线范围为0－20μg/L，检出限为0．01μg/L，在2μg/L、5μg/L含量水平测定，方法的相对标准偏差（RSD）分别为1．5％和0．54％，回收率在91％－110％之间。     

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%.     

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.     

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.     

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.     

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.     

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.