气相色谱法测定儿童EVA鞋材中的甲酰胺

采用乙醇作为提取溶剂,用超声萃取法对儿童EVA鞋材样品中残留的甲酰胺进行提取,然后采用气相色谱法进行检测,外标法定量。结果表明,本方法的线性关系良好,相关系数为0.999 7,检出限为5.0 mg·kg~(-1),加标回收率在90.23%~92.94%之间(n=6),相对标准偏差在3.7%~4.2%之间。该方法操作简单,精密度好,可以快速准确检测儿童鞋材中残留的甲酰胺含量。     

N-氨基磺酰基甲脒类化合物的合成研究

以二氯甲烷为溶剂,甲酰胺在三氯氧磷的活化作用下生成活性中间体,再与N-氨基磺酰胺发生缩合反应生成一系列的目标化合物,并通过红外光谱(FT-IR),核磁共振(NMR)和高分辨质谱(HR-MS)等分析方法进行结构表征。讨论了卤化试剂、温度、溶剂以及反应物投料比对产率的影响。结果表明,最佳反应条件为:三氯氧磷作为卤化试剂,二氯甲烷为溶剂,n(N-氨基磺酰胺)∶n(甲酰胺)=1∶1.5,温度为40℃,目标化合物的最高产率可达到95%。     

气相色谱-质谱法测定瑜伽垫中甲酰胺残留量

建立一种基于气相色谱-质谱法的准确、快速测定瑜伽垫中甲酰胺残留量的分析方法。以甲醇和丙酮为溶剂,经过超声萃取后,用气相色谱-质谱法对甲酰胺残留量进行定性和定量分析。甲酰胺残留量在0.1～100μg·mL~(-1)范围内与色谱峰面积呈良好的线性关系,线性相关系数为0.9993。用甲醇、丙酮浸提甲酰胺测定的相对标准偏差分别在3.0%～3.7%、3.4%～3.8%之间。对30批次瑜伽垫中甲酰胺残留量进行分析。结果表明:EVA和PVC材质瑜伽垫适合用甲醇为溶剂,橡胶材质瑜伽垫适合用丙酮为溶剂进行提取。该法准确、可靠,精密度高,适用于瑜伽垫中甲酰胺残留量的检测。     

提高1氢-1,2,4-三氮唑收率及品质的研究

以甲酰胺与水合肼为原料,采用液面下滴加水合肼、引入乙二醇作为反应溶剂、应用结晶-过滤-漂洗-烘干的后处理方式,合成了1氢-1,2,4-三氮唑,并对其合成工艺条件进行了研究。优化的反应条件为:m(乙二醇)=50%m(水合肼),n(甲酰胺)∶n(水合肼)=2.1∶1.0,反应温度为168℃,反应时间为120min。优化条件下,三氮唑收率为86.8%(以甲酰胺计三氮唑)或91.1%(以水合肼计),产品含量为98%,m.p.120～121℃。副产氨水中甲酰胺的含量为0.2%,水合肼的含量为0.1%。     

重结晶提纯碳酸二苯酯的溶剂选择

为了寻找重结晶法提纯碳酸二苯酯(DPC)的适宜溶剂,文章对DPC重结晶溶剂的选择及影响DPC纯度的因素进行了研究。结果表明:乙醇是重结晶纯化DPC的适宜溶剂,DPC在乙醇中溶解度在5—15℃的区间内变化缓慢,重结晶中止温度在15℃左右,DPC的收率高于89.0%。乙醇和DPC比率(质量比)采用8∶5为重结晶DPC时的适宜比率。通过对重结晶溶剂的进一步研究,发现采用水-乙醇的混合溶剂作为重结晶溶剂时,可以明显提高DPC的收率。水的质量分数在25.0%—35.0%范围内时,DPC的收率大于93.0%,纯度高于99.6%。其纯度符合合成聚碳酸酯的要求。     

气相色谱-质谱联用法测定婴幼儿地垫中甲酰胺残留量

建立了一种气相色谱-质谱联用(GC-MS)测定婴幼儿地垫中甲酰胺残留量的检测方法,考察了提取溶剂、提取方法、溶剂体积、提取时间和色谱柱对甲酰胺提取效果的影响。结果表明:在0.5～50 mg/L范围内,甲酰胺浓度与色谱峰面积呈良好的线性关系,线性相关系数r0.995,方法检出限为1.0 mg/kg;2.5、10、50 mg/kg3种添加水平下的平均回收率分别为89.5%、91.2%、93.3%,相对标准偏差(RSD)分别为3.62%、4.40%、5.32%。将该方法应用于实际样品的测定,可取得满意效果。     

N-氨基酰基甲脒类化合物的合成研究

以N-取代脲和甲酰胺为原料,合成了一系列N-氨基酰基甲脒类化合物,讨论了活化剂、溶剂、反应温度及底物投料比对反应的影响。结果表明,以草酰氯为活化剂、二氯甲烷为溶剂,在n(N-取代脲)∶n(甲酰胺)∶n(草酰氯)为1.0∶1.5∶1.2时,室温反应1～4 h可得到产率高达98%的目标化合物。该方法具有底物范围广、操作简便、反应条件温和、反应时间短、产率高等优点。     

钌金属配合物催化的丁香酚双键异构反应

以RuCl3·3H2O和三苯基膦制备钌金属配合物催化剂,研究钌金属配合物催化剂在不同溶剂中对丁香酚异构化反应的催化效果。研究结果表明,它在醇类等极性非质子溶剂中效果较好,其中以乙醇为溶剂时,转化率为98.3%,选择性为94.1%。在以乙醇为溶剂的条件下,考察了反应时间、催化剂用量、溶剂用量对丁香酚异构反应的影响,得出适宜的反应条件为:在乙醇回流温度下反应时间3 h,催化剂用量0.5%(按丁香酚质量比),溶剂用量300%(按丁香酚质量比)。在此条件下异丁香酚转化率为98.8%,其中反式异丁香酚选择性94.8%,得到的产品香气更为纯正。此外,还用红外、XRD和扫描电镜对RuCl2(PPh3)3催化剂进行了表征,研究了RuCl2(PPh3)3催化剂合成异丁香酚的反应机理。     

新型杀螨剂喹螨醚的合成研究

以邻氨基苯甲酸为原料,经甲酰胺缩合、三氯氧磷氯化,得到4-氯喹唑啉。叔丁基苯在铁粉的催化下溴化得4-叔丁基溴苯,再与镁和环氧乙烷进行格氏反应,得4-叔丁基苯乙醇,然后4-叔丁基苯乙醇在二氯甲烷溶剂中与4-氯喹唑啉醚化,得到喹螨醚。总收率64.2%。     

1—甲基—5—硫—四氮唑的化学分析

1—甲基—5—硫—四氮唑(?)是合成头孢氧哌嗪四唑、氧杂头霉唑等一系列新型头孢菌素的一个重要中间体。我厂研究所为了研制头孢氧哌嗪四唑(T—1551),首先成功地合成了该中间体。其熔点和红外光谱数据与文献相符。为了进一步确定其质量情况(未见文献报导这方面内容),我们分别用“银量法”;乙醇为溶剂的中和法;水为溶剂的中和法进行了含量测定。通过比较认为以乙醇为溶剂的中和法较为满意,详述如下。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

基于ATRP法制备的触角状亲水性羟胺树脂的吸硼性能的研究

以大分子引发剂氯乙酰化聚苯乙烯微球(PS-acyl-Cl)经原子转移自由基聚合(ATRP)法引发丙烯酰胺(AM)和甲基丙烯酸缩水甘油酯(GMA)单体的共聚接枝,制得一种触角状亲水性环氧载体(PS-acyl-g-P(AM-co-GMA)),再经二乙醇胺(DEA)的环氧基开环胺化反应,得到一种含多个-NCH2CH2OH螯合配基的多齿-五元螯合环的触角状亲水性羟胺树脂(PS-acyl-g-P(AM-co-GMA)-DEA)。将此树脂用于硼吸附研究,结果表明,PS-acyl-g-P(AM-co-GMA)-DEA树脂对硼的吸附满足Langmuir方程,为单分子层吸附;饱和吸附量约为37.7 mg·g-1,且树脂5 min即可达到吸附平衡,与其它已报道的吸硼树脂相比,该树脂具有更高的吸附量和吸硼速率。吸附动力学研究表明,树脂吸附硼的过程主要由颗粒扩散过程控制。重复使用5次后该树脂的吸附量基本不变,解吸率均在90%以上,重复使用性能良好。