高效液相色谱法测定食品中抗氧化剂BHA,BHT,PG

 用反相高效液相色谱法同时测定了食品中抗氧化剂丁基羟基茴香醚（ＢＨＡ）、二丁基羟基甲苯（ＢＨＴ）和焦性没食子酸丙酯（ＰＧ）。样品用正己烷提取，氮气吹干，水－乙醇（１４，Ｖ／Ｖ）溶解残留物，经０．５μｍ滤膜过滤，直接进样。方法简便、快速、回收率高、重现性好。     

同时测定食用植物油中抗氧剂叔丁基对羟基茴香醚和2，6－二叔丁基对甲酚的方法

报道了用高效液用色谱法同时测定食用植物油中的抗氧剂叔丁基对羟基茴香醚（ＢＨＡ）和２，６－二叔丁基对甲酚（ＢＨＴ）的实验方法。采用ＺｏｒｂａｘＯＤＳＣ_（１８）色谱住，甲醇：水（９０：１０，Ｖ／Ｖ）作流动相，检测波长为２４５ｎｍ，流速为１ｍＬ／ｍｉｎ。检测下限分别为１５ｎｇ（ＢＨＡ），９０ｎｇ（ＢＨＴ），回收率分别是９６．８％±９．８％（ＢＨＡ），９９．０％±３．２％（ＢＨＴ）。方法快速、准确，灵敏度高。     

同时测定食用植物油中抗氧剂叔丁基对羟基茴香醚和2，6－二叔丁基对甲酚的方法

 报道了用高效液用色谱法同时测定食用植物油中的抗氧剂叔丁基对羟基茴香醚（ＢＨＡ）和２，６－二叔丁基对甲酚（ＢＨＴ）的实验方法。采用ＺｏｒｂａｘＯＤＳＣ_（１８）色谱住，甲醇：水（９０：１０，Ｖ／Ｖ）作流动相，检测波长为２４５ｎｍ，流速为１ｍＬ／ｍｉｎ。检测下限分别为１５ｎｇ（ＢＨＡ），９０ｎｇ（ＢＨＴ），回收率分别是９６．８％±９．８％（ＢＨＡ），９９．０％±３．２％（ＢＨＴ）。方法快速、准确，灵敏度高。     

高效液相色谱法快速测定食品中抗氧化剂BHA,BHT

采用甲醇浸提食品样品中抗氧化剂ＢＨＡ（叔丁基羟基茴香醚）和ＢＨＴ（二叔丁基羟基甲苯），然后用高效液相色谱法测定提取液中的ＢＨＡ和ＢＨＴ。该法简单快速，准确性好，ＢＨＡ和ＢＨＴ的最小检出量分别为５ｎｇ和１０ｎｇ。     

N,N‘—二（2—羟基苄烯）—2—羟基苯甲基二胺及N,N’—二（2—羟基…

在四氢呋喃中合成了Ｓｃｈｉｆｆ碱配体Ｎ，Ｎ＇－二（２－羟基苄烯）－２－羟基苯甲基二胺（ＳＢ）与二阶过渡金属镍、铜、锌的三核或双核配合物；用钠汞齐还原ＳＢ得到了其氢化物Ｎ，Ｎ＇－二（２－羟基苄基）－２－羟基苯甲基二胺（ＨＳＢ），并在乙醇中合成了经与铜的双核配合物。对这些配合物进行了元素分析和热分析，并测定了电导、红外光谱和紫外光谱，确定了分子式，讨论了可能的配位结构。     

钴（Ⅱ）邻菲咯啉,8—羟基喹啉配合物＼Y型分子筛的制备,表征…

制备了钴（Ⅱ）邻菲咯啉，８－羟基喹配合物／Ｙ型分子筛，利用元素分析，ＴＧ－ＤＴＡ、ＳＥＭ、ＵＶ－Ｖｉｓ，ＢＥＴ及ＸＲＤ等方法确定了分子筛选中金属配合物的生成及其晶体结构，考察了实验参数对苯酚转化率及产物选择性的影响。     

双峰倍增配平法用于同步,导数—同步荧光法同时测定邻羟基苯甲酸和间 …

邻羟基苯甲酸（ｏ－ＨＢＡ）和间羟基苯甲酸（ｍ－ＨＢＡ）荧光光谱严重重叠，同步及导数技术虽使选择性有所改善，但仍不能完全分辨开重叠谱。用双峰倍配平计算法结合同步，一阶导数－同步荧光法对双组分体系（邻羟基苯甲酸／间羟基苯甲酸，ｐＨ１２介质）同时测定，结合计算的两种测定方法精密度，回收率和不同组分间浓度比范围均优于一阶导数－同步荧光法。     

铬（Ⅲ）邻菲咯啉,8—羟基喹啉配合物／Y型分子筛的制备及苯酚催化羟化

制备了铬（Ⅲ）邻菲咯啉，８－羟基喹啉配合物／Ｙ型分子筛，利用元素分析，ＳＥＭ，ＵＶ－ＶｉｓＢＥＴ及ＸＲＤ等方法确定了分子筛选笼中金属配合物的生在及其晶体结构，考察了实验参数对苯酚转化率及产物选择性的影响。     

聚β－羟基烷酸酯热分解行为的直接裂解质谱研究

用ＤＰＭＳ、ＴＧ、ＤＴＡ等方面研究了聚β－羟基丁酸酯（ＰＨＢ）及其共聚物Ｐ（ＨＢ－ｃｏ－ＨＶ）的热分解行为和某些结构性质，提供我至７个链节重复单元的裂解碎片，可较好地反应共聚物的组成和分布，结果表明：聚β－羟基烷酸酯的热分解具有较高的的选择性，通过β－Ｈ转移反应形成由羧基和烯烃结尾的齐聚物。     

Author Index Vol. 5, 1994

ＡｕｔｈｏｒＩｎｄｅｘＶｏｌ．５，１９９４ＡｌＣ．Ｂ．（４９３）ＡｌＷ．Ｑ．（２３９）ＡｎＤ．Ｌ．（５３７）（１０２７）（１０５５）（５１１）ＢａｂａＫ．（５９３）ＢａｔＤ．Ｌ．（９５）（４７１）ＢａｔＦ．Ｌ．（４１５）ＢａｔＮ．Ｓ．（７５７）Ｂａｔ...     

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.     

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.     

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.     

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.