高效液相色谱法同时测定制药废水中的交沙霉素、茶碱及扑热息痛

建立了同时测定制药废水中残留的交沙霉素、茶碱、扑热息痛等3种药物的高效液相色谱方法。样品经固相萃取处 理后进行色谱分析。采用的色谱条件:色谱柱为Hypersil ODS柱（4.6 mm i.d.×200 mm）;流动相A液为0.025 mol/L KH2PO4-H3PO4 缓冲液(pH 2.75),流动相B液为甲醇;梯度洗脱;紫外检测波长为230 nm(交沙霉素)、272 nm(茶碱)、243 nm(扑热息痛)。制药废水中3种药物的加标回收率均高于93%,相对标准偏差(n=6)小于2.1%,检测下限(S/N=3)不高于1.0 μg/L。该方法已应用于制药废水的生物强化降解研究。     

薄层流动时安法测定电镀废水中的铜

应用薄层流动时安法测定电镀废水中铜的含量 .试样溶液由流动状态转换为静止状态时的时库仑电量与铜离子浓度 (2～ 16mg/L)呈良好的线性关系 .对样品溶液进行 8次平行测定的相对标准偏差小于 0 .1% ,标准加入法测定的回收率为 99%～ 10 3% .该方法克服了电容电流及电极表面性质改变等噪声干扰 ,具有快速灵敏、准确、再现性好的优点     

高效液相色谱对液态奶中三聚氰胺的快速测定

建立了有机溶剂提取和离子对色谱相结合的三聚氰胺快速检测方法.样品中加入有机溶剂振荡提取,取上清液过滤进行高效液相色谱(HPLC)分析.对丙酮、乙腈、乙醇和异丙醇的提取物分别在甲醇-离子对试剂流动相体系和乙腈-离子对试剂流动相体系中进行测定和比较.结果显示,选择合适的流动相,使用丙酮、乙醇或异丙醇为提取剂可以获得较好的提取效果.在甲醇-离子对试剂流动相体系中,三聚氰胺的质量浓度在1.0 ～100.0 mg/L范围内与色谱峰面积呈良好的线性关系(r=0.999 98),检出限为0.1 mg/kg,采用丙酮为提取剂,加标回收率为97% ～103%,相对标准偏差(RSD)小于5%.     

头孢克洛干混悬剂中有关物质的研究

建立HPLC法测定头孢克洛干混悬剂中的有关物质.色谱柱为Hypersil C18 BDS柱,流动相A为0. 78%磷酸二氢钠溶液(pH 4. 0),流动相B为0. 78%磷酸二氢钠溶液一乙腈(体积比为55∶45),流速为1 mL/min,检测波长为220 nm.该方法测定结果的相对标准偏差为0. 01%(n=6),标示样品测定结果的相对误差不大于1. 0%,可满足企业质量控制的检测要求.     

流动注射化学发光法测定工业废水中苯酚

采用流动注射技术,研究了高锰酸钾-过氧化氢-苯酚的化学发光行为,对影响化学发光强度的因素进行了试验,建立了流动注射化学发光法测定苯酚的方法。方法的检出限为3×10-5g.L-1,线性范围为1.0×10-4~1.0×10-1g.L,对浓度为4.0×10-4g.L的苯酚作试验,求得其相对标准偏差(n=11)值为1.6%。方法用于废水中苯酚含量的测定,结果与分光光度法测得值一致。     

高锰酸钾-甲醛化学发光体系测定甲氧氯普胺

基于在甲醛的作用下,高锰酸钾对甲氧氯普胺的氧化作用而产生化学发光的现象,建立了一种新的用流动注射-化学发光法测定甲氧氯普胺含量的方法.该方法测定甲氧氯普胺的线性范围为0.2~100 mg/L,检出限为0.1 mg/L.对于8 mg/L的甲氧氯普胺标准溶液连续11次测定的相对偏差为1.2%.该方法可用于对制药废水、片剂和针剂中甲氧氯普胺含量的测定.     

反相高效液相色谱法检测鲫鱼肌肉中伊维菌素

以鲫鱼肌肉为材料,建立了一种简便、准确的反相高效液相色谱法,用于鱼肉中伊维菌素的药物残留检测和药代动力学研究.鲫鱼肌肉中的伊维菌素用乙酸乙酯提取,离心后的上清液于45 ℃下氮气吹干,残渣用甲醇-水(4∶ 1,V/V)混合液溶解,正己烷去脂,离心后取下清液,进样20 μL进行HPLC分析.本方法考察了提取剂、柱温和流动相的影响,确定了以乙酸乙酯为提取剂,柱温25 ℃和甲醇-水(90∶ 10,V/V)为流动相的优化条件.方法线性范围为0.025～2.50 μg/g,相关系数r=0.9997,检出限为11 ng/g.批内RSD为1.0%～5.8%,日间RSD为1.0%～7.7%,相对回收率(99.8±4.1)%, 绝对回收率为(95.9±3.9)%.本方法具有操作简便,结果准确可靠的特点.     

络合萃取法处理二甲胺废水

采用络合萃取法处理二甲胺(DMA)废水,考察了萃取剂的种类和用量、溶液pH值、油与水比对二甲胺萃取效果的影响. 实验结果表明,以P204为萃取剂、环己烷为稀释剂时,P204与DMA以1∶ 1形式络合,萃取是一个放热且快速反应过程,反应热ΔH=-6.50 kJ/mol. 在油与水比为1∶ 4、萃取剂稀释剂体积比为1∶ 9、废水pH=11.87的条件下,DMA的一级萃取率为93.0%. P204负载DMA的红外谱图研究表明,P204络合萃取二甲胺同时存在离子缔合成盐机制和氢键缔合机制.     

淀粉基阳离子絮凝剂的研制及性能测试

用可溶性淀粉为原料,通过接枝改性合成了一种淀粉基阳离子絮凝剂(MSF),其最佳制备工艺条件为:淀粉与丙烯酰胺的质量比为1:2,引发剂用量为0.6 g,反应温度为50 ℃,接枝时间为3.5 h;阳离子化条件为:甲醛和二甲胺摩尔比为1.0:1.4,反应时间2.5 h,反应温度50 ℃.产物结构经FTIR证实.用其处理番茄废水后,废水的透光率提高了78.2%、TOC下降了22.5%、COD下降了37.25%,结果表明该产品对高浓度有机废水的絮凝性能优于聚丙烯酰胺高分子絮凝剂(PAM).     

柱上衍生反相高效液相色谱法测定疾藜提取物中痕量铅

提出了微波消解样品,在线衍生测定疾藜提取物中痕量铅的反相高效液相色谱方法.双水杨醛邻苯二胺为衍生剂,用DiamonsilTM C18色谱柱(4.6 mm×150 mm,5um)作为固定相,甲醇-水-衍生剂(64.5:34.0:1.5体积比)为流动相,检测波长为275 nm,柱温30℃.样品中铅在0.10～0.63 ng范围内呈线性,铅的平均回收率为99.5%,相对标准偏差(n=7)为1.8%.     

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

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.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.