固相萃取-气相色谱法测定纺织品中的邻苯二甲酸酯类环境激素

采用索氏提取法以正己烷为提取溶剂提取纺织品中的邻苯二甲酸酯类物质(PAEs),以强阴离子交换固相萃取(SPE)小柱净化本底杂质并富集待测物,建立了纺织品中10余种PAEs环境激素的同时测定方法。采用的固相萃取条件为:5 mL正己烷活化、3 mL异辛烷淋洗、2 mL含15%乙酸乙酯的正己烷溶液洗脱。SPE能有效地对提取液进行富集浓缩,同时对纺织物提取液中的杂质净化效果突出。该方法准确可靠,重现性好,在5~100 mg/kg 添加水平,PAEs各化合物的回收率为86.3%~102.7%,相对标准偏差（RSD）一般小于5%。检测的10余种PAEs中邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丙酯(DPrP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二戊酯(DAP)、邻苯二甲酸丁基苄基酯(BBP)、邻苯二甲酸二环己酯(DCHP)、邻苯二甲酸二(2-乙基己基)酯(DEHP)、邻苯二甲酸二正辛酯(DNOP)的方法检出限小于1mg/kg,邻苯二甲酸二异壬酯(DINP)与邻苯二甲酸二异癸酯(DIDP）的方法检出限分别为1.74 mg/kg和1.55 mg/kg。     

气相色谱法测定邻苯二甲酸酯

建立了气相色谱分析邻苯二甲酸酯的方法.选择邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二异丁酯(DIBP)、邻苯二甲酸二正丁酯(DBP)、邻苯二甲酸丁苄酯(BBP)、邻苯二甲酸二(2-乙基己基)酯(DEHP)、邻苯二甲酸二正辛酯(DOP)7种标物,对实验方法的准确程度进行了分析.7种标物的线性相关系数都能达到0.999以上,线性范围在0.01～1g/L之间;保留时间的相对标准偏差都在0.1%以内,峰面积的相对标准偏差在2%以内.     

超高效液相色谱法测定香型中性笔墨水中10种PAEs

建立超高效液相色谱–二极管阵列检测器测定香型中性笔墨水中邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二正丙酯(DPP)、邻苯二甲酸丁基苄酯(BBP)、邻苯二甲酸二正丁酯(DBP)、邻苯二甲酸二正戊酯(DAP)、邻苯二甲酸二环己酯(DCHP)、邻苯二甲酸二正己酯(DHP)、邻苯二甲酸二(2-乙基己基)酯(DEHP)和邻苯二甲酸二正辛酯(DNOP)10种邻苯二甲酸酯(PAEs)的方法。样品采用甲醇涡旋超声提取,色谱柱为Waters ACQUITY UPLC BEH C_(18)柱(100 mm×2.1 mm,1.7μm),以乙腈–水为流动相进行梯度洗脱,用PDA检测器检测,10 min内完成10种邻苯二甲酸酯的检测。10种邻苯二甲酸酯的质量浓度在5.0~200.0 mg/L范围内与其色谱峰面积呈良好的线性关系,线性相关系数均大于0.999,检出限为3.2~4.0 mg/kg;在高低两个添加水平下,10种邻苯二甲酸酯的回收率为96.3%~104.1%,测定结果相对标准偏差为0.1%~2.9%(n=6)。该方法样品处理简单,提取效率高,分离效果好,且灵敏度高,能快速准确测定香型中性笔墨水中10种邻苯二甲酸酯。     

基于PA6纳米纤维膜固相萃取-液相色谱法检测牛奶中的邻苯二甲酸酯

采用静电纺丝法制备了聚酰胺6(PA6)纳米纤维膜,结合固相萃取技术-液相色谱法(HPLC-UV)检测了市售牛奶样品中的6种邻苯二甲酸酯(PAEs)的含量.对影响实验的各种因素,如提取溶剂的种类及用量、超声时间、洗脱溶剂的种类及用量、纳米纤维膜的用量、pH及过样速度等进行了考察.在最优化条件下,邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸丁基苄酯(BBP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二(2-乙基己)酯(DEHP)和邻苯二甲酸二正辛酯(DOP)的检出限分别为0.02,0.01,0.05,0.05,0.10和0.25ng/mL.将该方法应用于不同品牌不同包装牛奶样品的检测,只需2.5mg PA6纳米纤维膜,即可完全萃取样品中的PAEs,相对标准偏差(RSD)小于5.82%,回收率为93.40%～104.83%.该方法测定牛奶中PAEs环境雌激素,检出限低,灵敏度高,结果准确可靠,重现性好.     

GC-EI-MS内标法分析鱼肉中邻苯二甲酸酯

鱼肉样品以Florisil硅藻土层析柱净化后, 经气相色谱-电子轰击离子源-质谱法(GC-EI-MS)分析其中8种邻苯二甲酸酯(PAEs)含量: 邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丙酯(DPrP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸丁基苄基酯(BBP)、邻苯二甲酸二戊酯(DPeP)、邻苯二甲酸二环己基酯(DCHP)、邻苯二甲酸二己酯(DHP)、邻苯二甲酸二(2-乙基己基)酯(DEHP). 比较了外标和内标法定量, 并确定苯甲酸苄基酯为内标物; 优化了提取剂、吸附剂和洗脱剂的种类, 以及洗脱体积等样品前处理方法; 尤其对分析空白的控制问题进行了详细讨论; 准确分析了5种鱼样品中此类物质含量. 该方法的线性范围为50.0～800 μg•L^－1, 相关系数(R)大于0.99986, 相对标准偏差(Relative standard deviation, RSD)均小于12.7%, 检测限(Limit of detection, LOD)低于3.66 μg•L^－1, 样品的加标回收率为74.0%～113%. 其线性范围、相关系数、准确度、精密度和LOD等指标均满足鱼肉中多种PAEs同时分析的要求.     

气相色谱-质谱法测定玩具中邻苯二甲酸酯类增塑剂

采用二氯甲烷作为萃取溶剂,超声提取塑料玩具和毛绒玩具中的6种增塑剂,提出了邻苯二甲酸二正丁酯(DBP)、邻苯二甲酸(2-乙基己基)酯(DEHP)、邻苯二甲酸二异壬酯(DINP)、邻苯二甲酸丁苄酯(BBP)、邻苯二甲酸二正辛酯(DNOP)和邻苯二甲酸二异癸酯(DIDP)等6种增塑剂的气相色谱-质谱分析方法。在选定的试验条件下,BBP、DBP、DEHP和DNOP可以完全分离,通过比较保留时间、色谱图和峰面积(m/z 149),可实现以上4种物质的定性和定量分析。而DIDP和DINP的峰重叠,需通过选择m/z293,307质谱峰进行定量分析。结果表明方法能够有效地检测出玩具中邻苯二甲酸酯类增塑剂的含量。     

气相色谱法同时测定聚氯乙烯中的八种增塑剂

邻苯二甲酸酯作为增塑剂和耐寒剂已广泛应用于塑料制品中，但其致癌性也日益引起人们的关注。因此对增塑剂含量的分析和研究十分必要。本文用气相色谱法(GC)对聚氯乙烯(PVC)材料中的邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸苄丁酯(BBP)、邻苯二甲酸双(2-乙基己)酯(DEHP)、邻苯二甲酸二异壬酯(DINP)、邻苯二甲酸二正辛酯(DNOP)、邻苯二甲酸二异癸酯(DIDP)等8种邻苯二甲酸酯的残留量进行了测定。方法简便、快速、灵敏。     

牛奶中酞酸酯污染物的气相色谱质谱-联用测定

建立了气相色谱.质谱法(GC-MS)测定市售牛奶中4种酞酸酯(邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二异丁基酯(DiBP)、邻苯二甲酸二丁基酯(DBP),邻苯二甲酸二(2-乙基己基)酯(DEHP))的方法.样品采用乙酸乙酯直接萃取,C18小柱净化,过0.45μm滤膜,直接注入GC-Ms进行分析.保留时间定性,外标法定量.4种酞酸酯的回收率为77.9%～109.07%;精密度(RSD)为1.72%～6.18%;检测限在0.15～60 ng之间.     

基质固相分散-液相色谱-质谱法测定蔬菜中的邻苯二甲酸酯

采用基质固相分散-液相色谱-质谱法测定保护地蔬菜中邻苯二甲酸酯(PAEs)含量,并分析了蔬菜中PAEs污染状况,研究了水和洗涤液浸泡对蔬菜中PAEs的消除效果。蔬菜样品经弗罗里硅土和石墨化碳黑研磨均匀后,用乙酸乙酯淋洗净化,再用液相色谱/电喷雾质谱法测定。PAEs的添加回收率为82.7%~105.7%;RSD为1.7%~6.1%;检出限为邻苯二甲酸二甲酯(DMP):0.99ng;邻苯二甲酸二乙酯(DEP):0.75ng;邻苯二甲酸二丁酯(DBP):0.70ng;邻苯二甲酸二异辛酯(DEHP):1.9ng。本方法前处理简单,具有较高的准确度和灵敏度。黄瓜、番茄、西葫芦中4种PAEs总量分别为2.02、1.26、0.91mg/kg;洗涤实验结果表明,水和洗涤液浸泡可显著降低蔬菜中的PAEs含量。     

高效液相色谱二极管阵列检测器测定化妆品中的6种酞酸酯

建立了用高效液相色谱二极管阵列检测器测定化妆品中6种酞酸酯——邻苯二甲酸二甲酯(DMP)、二乙酯(DEP)、二丁酯(DBP)、丁基苄基酯(BBP)、二(2-乙基己)酯(DEHP)和二正辛酯(DOP)的方法一样品用甲醇超声提取．高速冷冻离心,经0．5μm滤膜过滤．直接注入高效液相色谱．在280nm波长进行分析用保留时间结合酞酸酯紫外光谱定性．外标法定量该法的回收率为85％～110％．精密度RSD为0．058％～2．84％．检出限：DMP．DEP、BBP和DBP均为5ng．DEHP和DOP为10ng,该方法准确度和灵敏度高．样品用量少．前处理简单。可同时测定化妆品中6种酞酸酯化合物。     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.     

Exploring the scope of the Gewald reaction: Expansion to a four-component process

An efficient four-component reaction was developed to take advantage of the reactivity of the 2-aminothiophene-3-carbonitrile functionality, which is obtained during the classical three-component Gewald reaction. Various α-methylene bearing ketones were reacted with malononitrile, elemental sulfur, and aryl/heteroarylnitrile derivatives in t-BuOH/NaOH to afford 2-arylthieno[2,3-d]pyrimidin-4-amines in high yields. Preliminary studies revealed the photophysical properties of the products and their potential for use as metal sensors.