离子交换色谱法测定间苯二甲酸生产工艺中间物料及产品中的阴离子

建立了用离子交换色谱法同时测定间苯二甲酸生产工艺中中间物料及产品中F-、Cl-、Br-、OAc-、NO3-、PO43-和SO42-等7种阴离子的分析方法。采用A SUPP 5-250阴离子交换柱,以2.8 mmol.L-1Na2CO3和1.2 mmol.L-1NaHCO3混合溶液为流动相,在20 min内有效地分离和测定了样品中上述7种阴离子。采用抑制型电导检测,以S/N=3计算,F-、Cl-、Br-、OAc-、NO3-、PO43-和SO42-等离子的检出限分别为0.10,0.40,0.35,0.25,2.50,0.25和0.90μg.L-1,相关系数在0.999 1~0.999 7范围内;峰面积的相对标准偏差小于1.3%,加标回收率在98.2%~100.3%之间。     

离子色谱法测定农村饮用水中阴离子

采用离子色谱法测定农村饮用水中F-、Cl-、NO2-、Br-、NO3-和SO42-等6种阴离子的含量。水样经Ion Pac AG19保护柱及Ion Pac AS19分离柱分离,以20.00mmol·L-1氢氧化钾溶液为淋洗液,采用抑制电导器检测。F-、NO2-和Br-在4mg·L-1以内,Cl-、NO3-和SO42-在40mg·L-1以内呈线性关系,检出限(2S/N)在0.002～0.012mg·L-1之间。方法用于水样中6种阴离子的测定,加标回收率在98.0%～101.3%之间,相对标准偏差(n=6)在0.83%～2.7%之间。     

离子色谱法测定茶叶中的无机阴离子

提出了离子交换色谱法分离测定茶叶中F-、Cl-、Br-、NO3-、H2PO4-和SO2-4 6种无机阴离子含量的方法.茶叶样品中6种阴离子用水在95℃超声萃取20 min后,经IonPac ASll-HC阴离子分离柱,AGll-HC阴离子保护柱,以氢氧化钾为淋洗液,浓度从15 mmol·L-1到30 mmol·L-1进行梯度淋洗.F-、Cl-和Soi2-4的峰面积与其质量浓度在0.01～150.0 mg·L-1范围内,H2PO-4、NO-3和Br-在0.05～150.0 mg·L-1范围内呈线性关系.6种离子的检出限(3S/N)均小于0.03 mg·L-1.该方法用于茶叶样品中F-、Cl-、Br-、NO-3、H2PO-4和SOi2-4的测定,加标回收率在90.9%～100.0%之间,测定值的相对标准偏差(n=5)小于3.5%.     

离子色谱法测定茶叶中无机阴离子及其用于茶叶的分类

提出了离子色谱法测定茶叶中F-、Cl-、NO2-、Br-、NO3-、H2PO4-、SO42-等无机阴离子的方法。采用Shodex IC SI-52 4E阴离子分离柱进行分离,以3.6mmol.L-1碳酸钠溶液和甲醇以体积比98比2混合所得溶液为淋洗液进行洗脱,从而实现7种阴离子的分离。根据茶叶中分离出的7种阴离子含量的不同,利用聚类分析将16个茶叶样品进行分类。     

离子色谱法测定工业甲酸中4种痕量阴离子

用离子色谱法(IC)测定了工业甲酸中4种痕量阴离子F-、Cl-、NO3-和SO42-。取样品(20.000g)加入100g·L-1碳酸钠溶液0.4mL于水浴上蒸发至干,残渣溶于水中并定容至100mL作为试液供IC测定。将样品蒸干处理可消除甲酸的基体干扰,加入碳酸钠可避免F-及Cl-以氢氟酸及盐酸形式挥发损失。色谱分离时用IonPacTM AG23保护柱和IonPac AS23分离柱,并用4.5mmol·L-1碳酸钠-0.8mmol·L-1碳酸氢钠缓冲溶液作为淋洗液。在所选分析条件下,上述4种阴离子的质量浓度分别在一定范围内与相应峰面积呈线性关系,其检出限(3S/N)依次为0.01,0.02,0.03,0.03mg·L-1。以实样为基体,用标准加入法进行回收试验,测得回收率在96.2%~106%之间。     

在线渗析-离子色谱法测定蔬菜中无机阴离子

采用在线渗析技术与离子色谱法联用测定蔬菜等样品中多种阴离子.样品提取后,取上层清液经渗析后进入分离柱,采用Metrosep A Supp 4-250阴离子交换柱,以1.8 mmol·L-1Na2CO3与1.7 mmo·L-1NaHCO3混合溶液为流动相,化学抑制电导检测.方法中各阴离子检出限(3S/N)为1-18ug·L-1.方法用于复杂基质蔬菜样品中F-、Cl-、NO-2、Br-、NO-3、PO3-4和SO2-4等阴离子的测定,加标回收率均大于78%,相对标准偏差(n=6)在1.8%～6.1%之间.     

萃取分离-离子色谱法测定间羟基-N,N-二乙基苯胺中的无机阴离子

建立了检测常用化工原料间羟基-N,N-二乙基苯胺中无机阴离子(F-、Cl-、NO3-和SO42-)含量的萃取分离-离子色谱分析方法。方法以甲苯为溶剂溶解间羟基-N,N-二乙基苯胺,用水相萃取分离得到其中的无机阴离子F-、Cl-、NO3-和SO42-等;色谱柱采用Metrosep A supp 5型阴离子分离柱,流动相为3.2 mmol/L Na2CO3与1.0 mmol/L NaHCO3的混合液,流速0.7 mL/min。结果表明:F-、Cl-、NO3-和SO42-的线性关系分别为y=1.2036x 1.0703(r=0.9999)、y=1.3999x-0.2531(r=0.9999)、y=2.6612x-0.9482(r=1.0000)、y=1.9337x 0.0719(r=0.9999);平均回收率分别为F-101.6%(RSD 5.92%),Cl-107.6%(RSD 4.82%),NO3-106.9%(RSD 3.08%),SO42-95.17%(RSD 3.32%);检出限分别为:F-0.003 mg/L、Cl-0.005 mg/L、NO3-0.016 mg/L和SO42-0.010 mg/L。该方法简便、快速、灵敏度高,具有较强的实用价值。     

离子色谱法测定大气降尘中四种阴离子

以流速 1.5ml·min- 1,0 .2 4mol·L- 1Na2 CO3和 0 .30mol·L- 1NaHCO3混合液为淋洗液 ,在YSA 4型阴离子分离柱上分离 ,采用带电导检测器的离子色谱仪对大气降尘中四种阴离子进行分离测定 ,F- 、Cl- 、NO- 3、SO2 - 4的检出限 (3S/N)分别为 0 .0 0 1,0 .0 0 1,0 .0 0 6 ,0 .0 0 4mg·L- 1,相关系数分别为 0 .9991,0 .9986 ,0 .9997,0 .9984 ,RSD分别为 0 .80 % ,0 .76 % ,1.80 % ,1 90 %。     

离子色谱法测定银杏叶中无机阴离子

应用离子色谱法测定了银杏叶中6种无机阴离子(F-,Cl-,NO-2,PO3-4,NO-3及SO2-4),测定中采用了Y5AB-8041A型阴离子分离柱及电导检测器,用含有5.0 mol·L-1碳酸钠溶液及5.4 mmol·L-1碳酸氢钠溶液的混合液作为洗脱液,以1.5 mL·min-1的流速通过分离柱.6种阴离子的峰高值与浓度值在一定范围内呈线性关系,其相关系数在0.999 1～0.999 7之间.测得6种阴离子的检出限(以μg·L-1表示)依次为2.75,4.71,9.43,11.1,30.0及22.4.用含6种阴离子的混合标准溶液,连续测定5次,检测方法的精密度,算得其相对标准偏差≤0.94%.用标准加入法测定了方法的回收率,测得结果在96.4%～102.3%之间.     

大体积进样-离子色谱法测定炉水中痕量阴离子

提出了大体积进样-离子色谱法测定火电厂炉水中8种阴离子F-、CH3COO-、HCOO-、Cl-、NO2-、NO3-、SO42-及PO43-的含量。水样经AG17-C保护柱及AS17-C分离柱分离,以氢氧化钾溶液为淋洗液进行梯度淋洗,采用抑制电导器检测。8种阴离子的质量浓度均在5.0～50μg·L-1范围内与峰面积呈线性关系,检出限(2S/N)在0.01～0.11μg·L-1之间,测定下限(10S/N)在0.05～0.52μg·L-1之间。方法用于火电厂炉水中8种阴离子的测定,加标回收率在97.8%～107%之间。     

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.     

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.