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1.
流动注射在线共沉淀预富集火焰原子吸收法测定痕量铜   总被引:3,自引:0,他引:3  
研究了以Ni^2+-DDTC为共沉淀载体,流动注射在线共沉淀预富集-火焰原子吸收光谱法测定痕量铜的体系,在0.3mol.L^-1的硝酸介质中,铜离子在编织反应器中与Ni^2+-DDTC(产生共沉淀,并被收集在编织器内壁上,用甲基异丁基酮(MIBK)在线洗脱沉积物并引入火争原子化器中测定。当富集时间为40s时,40μg.L^-1的铜10次测定的相对标准偏差为3.0%,灵敏度提高60倍,检出限(3σ)  相似文献   

2.
采用循环伏安曲线,电子探针,X射线衍射法,研究了尿素-NaCl-NaAc-CoCl2-LaCl3熔体中镧钴电解共沉积,阴极电位,电流密度,熔体中La^3+/Co^2+摩尔比以及电极基体均影响沉积物中的含镧量。沉积物由Co和La组成,两者并末形成金属间化合物。  相似文献   

3.
(R)-N-酰基四氢噻唑-2-硫酮-4-羧酸在DCC存在下与胺的反应   总被引:3,自引:2,他引:1  
由N-乙酰四氢噻唑-2-硫酮-4-羧酸([α]20D-109.83°),及N-苯甲酰四氢噻唑-2-硫酮-4-羧酸([α]20D-112.22°),在N,N′-二环己基二亚胺(DCC)存在下分别与环己胺、苯胺反应得到光学活性产物(R)-N-乙酰四氢噻唑-2-硫酮-4-甲酰环己胺([α]17D-74.5°),及(R)-N-苯甲酰四氢噻唑-2-硫酮-4-甲酰苯胺([α]19D-7.04°)。用量子化学PM3方法研究了反应物和产物的电子结构。  相似文献   

4.
李叶芝  郎美东 《合成化学》1997,5(3):284-286,283
(R)-N-乙酰四氢噻唑-2-硫酮-4-羧酸与醇反应,在SOCl2存在下得到乙酸酯及四氢噻唑-2-硫酮-4-羧酸酯;在碳酸钾存在下得到乙酸酯及四氢噻唑-2-硫酮-4-羧酸;在二环己基碳二亚胺(DCC)存在下得到缩水产物N-乙酰四氢噻唑-2-硫酮-4-羧酸酯。  相似文献   

5.
合成了1-羟基-2-(1H)-吡啶硫酮(HPT)及其甲基衍生物的[AuL2]OH型配合物(L=PT-,3-CH3-PT-和4-CH3-PT-).用元素分析,紫外光谱,红外光谱,1HNMR谱,摩尔电导,TG-DTA-DTG进行了表征,用循环伏安法研究其氧化还原性质,含甲基的配合物有较强的抑菌活性。  相似文献   

6.
景凤英  姜洪焱 《分析化学》1998,26(4):461-465
利用一维NMR方法研究了新型聚芳醚酮大环化合物的影响,用二维同核^1H-^1H COSY和^13C-^1H COSY实验方法以及类似物质标准谱图的比较,对一维NMR谱峰进行了归属。  相似文献   

7.
合成了1-羟基-2-(1H)-吡啶硫酮及其甲基衍生物[AuL2]OH型配合物(L=PT^-,3-CH3-PT^-T 4-CH3-PT^-)。用元素,紫外光谱,外红光谱,^1HNMR谱,摩尔电导,TGDTA-DTG进行了表征,用循环伏安法研究其氧化还原性质,含甲基的配合物有较强的抑菌活性  相似文献   

8.
薄层色谱法检测甘薯呋喃萜类毒素   总被引:1,自引:0,他引:1  
沈业寿 《色谱》1997,15(4):328-330
 甘薯呋喃萜类毒素是甘薯受到损害后产生的强制性代谢产物,可用乙醚提取。乙醚提取物分别用5%Na2CO3和蒸馏水洗涤,无水硫酸钠干燥,蒸去乙醚。残渣(粗品)采用薄层色谱法进行检测,以纯品甘薯酮和甘薯酮醇作标样。结果表明:在20℃条件下,在石油醚-醋酸乙酯(21,V/V)和苯-甲醇(91,V/V)两种溶剂系统中,对甘薯酮(C)、甘薯酮醇(A)、化合物B和D的呋喃萜类毒素具有较好的分离效果,Rf值的重复性也较好。展开后的薄层板可以通过CS-930TLC扫描仪在527nm下扫描定量。  相似文献   

9.
杨桂春  黄锦霞 《合成化学》1998,6(3):324-327
用TeCl4催化含有活泼亚甲基的羰基化合物与醛的Knoevenagel反应,合成了一系列α,β-不饱和酮或酯,收率最高达95%。  相似文献   

10.
沸石在环己烯水合反应中的催化性能   总被引:1,自引:0,他引:1  
用Hβ及不同方法制得的HZSM-5沸石作催化剂,对环己烯-水,环己烯-水-乙酸两种反应体系中的水合反应进行了研究。用GC-IR对产物进行了定性分析。用BET重量法测定了各种沸石对反应物的饱和吸附量。结果表明,在两种反应体系中,Hβ的催化活性显著地高于HZSM-5。GC-IR分析表明,在HZSM-5上,主要副产物是环己烯-[1]-酮-[3]和4-甲基环戊烯;在Hβ沸石上,主要副产物是2-环己烯基环己  相似文献   

11.
建立了测定水产养殖环境沉积物中多肽类抗生素残留量的高效液相色谱串联质谱法。沉积物经10 mL甲醇-柠檬酸-Na2 HPO4溶液(3∶4, V/ V)超声提取2次,0.5 g 乙二胺四乙酸二钠络合除杂,5 mL 甲基异丁基甲酮净化,HLB 固相萃取柱进一步富集净化,MGII C18色谱柱分离,0.1%甲酸与0.1%甲酸-乙腈梯度洗脱,ESI+电离,多反应监测模式(MRM)监测,外标法定量。粘菌素和杆菌肽在10~10000μg/ L 范围内,维吉尼霉素 M1在4~4000μg/ L 范围内,线性回归系数均大于0.999,方法检出限为2~5μg/ kg,方法定量限为4~10μg/ kg。在3个浓度添加水平下,多肽类抗生素回收率79.7%~91.6%,相对标准偏差1.9%~10.8%。本方法具有良好的精密度和准确度,灵敏度高,适用范围广。  相似文献   

12.
ABSTRACT: BACKGROUND: Taihu Lake is a typical plain eutrophic shallow lake. With rapidly economic development of the lake area, the petroleum products and oil wastewater produced in various processes have been inevitably discharged into Taihu Lake. As the major fresh water resource in the economically developed region of Yangtze River Delta, the water quality and environmental condition of Taihu Lake have the direct bearing on the natural environment and sustainable development of economy in this region. For this reason we carried out the study to explore the composition, distribution characteristics and sources of petroleum contaminants in Taihu Lake. The aim of this study was to provide the basis for standard management and pollution control of the Taihu Lake environment. RESULTS: The result showed that water samples from near industrial locations were of relatively higher petroleum contaminants concentrations. The oil pollutants concentrations in different areas of Lake Taihu ranged from 0.106 mg/L to 1.168 mg/L, and the sequence of total contents distribution characteristics of petroleum pollutants from high to low in different regions of Taihu Lake was: "Dapu", "Xiaomeikou", "Zhushan Bay", "Lake center", "Qidu". The results showed that total concentrations of n-alkanes and PAHs ranged from 0.045 to 0.281 mg/L and from 0.011 to 0.034 mg/L respectively. In the same region, the concentrations of hydrocarbon pollutants in the surface and bottom of the lake were higher than that in the middle. CONCLUSION: This paper reached a conclusion that the petroleum contaminants in Taihu Lake mainly derived from petroleum pollution caused by human activities as indicated by OEP, bimodal distribution, CPI, Pr/Ph ratio, the LMW/HMW ratio and other evaluation indices for sources of n-alkanes and polycyclic aromatic hydrocarbons (PAHs).  相似文献   

13.
微孔多酸CsxH5-xPW10V2O40/SiO2的制备及氧化催化作用   总被引:7,自引:0,他引:7  
Keggin结构杂多酸在固相体系中的催化作用引起了人们的极大兴趣[1~3].性能稳定的杂多酸铯盐催化剂在非均相催化体系中已有广泛的应用,然而由于其在液固体系中通常呈现牛奶状,难以分离和重新使用,尽管化学家们以各种材料作为这些催化剂的载体进行了许多固载化尝试[4~6],但至今尚未从根本上解决这一难题.因此,开发高比表面的耐水微孔固体杂多酸催化剂是多酸催化化学领域中具有理论和实际意义的课题.本文采用Sol-Gel技术,以正硅酸乙酯(TEOS)为硅源,水解产生的具有网络结构的SiO2凝胶为载体,在钒取代型Keggin结构杂多酸CsxH5-xPW10V2O40存在下,制得通式为CsxH5-xPW10V2O40/SiO2的固体双功能微孔杂多酸; 以30%H2O2为氧化剂,以苯甲醇氧化为模型反应,研究其液-固体系中的催化作用.  相似文献   

14.
含间苯基聚醚酮醚酮酮的合成和性能研究   总被引:12,自引:0,他引:12  
自英国ICI公司开发聚醚醚酮(PEEK)并于八十年代初期商品化以来[1],聚芳醚酮作为一类新型结构的高性能特种工程塑料得到了惊人的发展,不同结构的聚芳醚酮相继出现.Janson[2]等以对苯二甲酰氯(TPC)和4,4′ 二苯氧基二苯酮(DPBP)为单...  相似文献   

15.
建立了高效液相色谱-质谱联用技术结合固相萃取和液液萃取方法检测水体和沉积物中12种磷酸酯类(OPEs)化合物残留的方法.水样样品经HLB固相萃取柱富集,乙酸乙酯洗脱两次,沉积物样品以乙腈超声萃取,旋转蒸发至干,用超纯水稀释后重复水样处理步骤,采用ZORBAX Eclipse Plus C18色谱柱(150 mm×2.1 mm, 3.5 μm)进行分离,以0.2%甲酸-甲醇作为流动相进行梯度洗脱,采用正离子MRM监测模式,外标法定量分析.水样中,12种OPEs在0.05、0.10和0.50 μg/L加标水平下,除TMP (28.5%~47.8%)和TEHP (22.4%~73.8%) 外,其余目标化合物的平均回收率为66.4%~115.0%,相对标准偏差为0.5%~9.1%,方法定量限(MOQ)为0.001~0.050 μg/L;沉积物中,在5、10和50 μg/kg加标水平下,除TMP(35.7%~44.9%)、TCEP (31.2%~48.9%)外,其余目标化合物的平均回收率为65.9%~120.0%,相对标准偏差为0.01%~9.5%,方法定量限(MOQ)为0.02~2.0 μg/kg(dw).基于上述方法对太湖水样和沉积物样品中目标化合物定量检测分析,∑OPEs含量分别为0.1~1.7 μg/L和8.1~420 μg/kg dw.  相似文献   

16.
Schiff碱N-氧化吡啶-2-甲醛缩氨基硫脲的晶体结构   总被引:4,自引:0,他引:4  
刘斌  胡瑞祥  梁宏  郁开北 《结构化学》1999,18(6):414-417
合成了标题Schiff碱并获得了其单晶,化学式为C7H8N4OS,Mr= 196.23,经X射线单晶衍射分析,该晶体属于单斜晶系,空间群为C2/c,晶胞参数: a= 13.198(2),b= 8.070(1),c= 16.999(2),β= 102.760(10)°,V= 1765.8(4)3,Z= 8,Dc=1.476g/cm 3,μ= 0.330m m - 1,F(000)= 816,在2.46°< θ< 29.00°范围内以ω扫描方式收得独立衍射点2347 个,其中I> 2σ(I)的可观测点为1687 个。最终偏离因子R=0.0344,w R= 0.0843,(Δ/σ)m ax= 0.001,S= 1.082。分子为平面构型。与相应配合物的晶体结构进行了比较并讨论了配位前后标题化合物主要的键性质的变化。  相似文献   

17.
The rates of pyrolysis of 4-chloro-2-butanone in the gas phase have been determined in a static system seasoned with the products of decomposition of allyl bromide. The reaction is catalyzed by hydrogen chloride. Under maximum catalysis of HCl, the kinetics were found to be of order 1.5 in the substrate suggesting that a complex elimination is involved. The reaction, when maximally inhibited with propene, appears to undergo a unimolecular elimination and follows a first-order law kinetics. The products are methylvinyl ketone and hydrogen chloride. The kinetics have been measured over the temperature range of 402.0–424.4°C.The rate coefficients are given by the Arrhenius equation \documentclass{article}\pagestyle{empty}\begin{document}$ \log k_1 (\sec ^{ - 1}) = (13.67 \pm 0.69) - (225.2 \pm 8.6)\,{\rm kj}/{\rm mol}/2.303RT\angle $\end{document}. Thepyrolysis of 4-chloro-2-butanone is 31 times greater in rate than that of ethyl chloride at 440°C. This large difference in rate may be attributed to the -M effect of the acetyl substituent in the pyrolysis of the former halo compound.  相似文献   

18.
关喆  郑莹  焦书科 《高分子学报》2001,27(6):779-782
以Al(i Bu) 3 为活化剂 ,对球形MgCl2 负载的MAO Et[Ind]2 ZrCl2 催化剂用于乙烯淤浆聚合的动力学进行了研究 .确定了动力学控制条件后 ,测定了聚合反应级数和表观活化能 ,用动力学外推法计算出活性中心浓度和链增长速率常数 ,用扫描电镜观察了聚合过程中聚合物形态的变化 ,发现聚合是在催化剂的次级粒子上进行 ,催化剂粒子无明显破碎  相似文献   

19.
CHEN Zhi  |Rong  a  LI Jian  |Hui  b  LI Hong  |Jun  a a   《结构化学》2000,(1)
1 INTRODUCTIONInrecentyears,theziniccompoundscontainingsulfurandnitrogenattractmoreandmoreattentionbecauseoftheirdeeprelationshipwithbio-inorganicchemistry〔1〕.Zinicsulfideplaysanimportantroleduetoitssignificantinvolvementinthestudyofthephosphors,semi…  相似文献   

20.
Synthetic musks, substitutes for natural musks, are widely distributed in environment. They have been detected in water, sludge, fish, shrimp, mussels and other aquatic animals, and even in human's adipose tissue, blood and breast milk. In this study, a new extraction procedure, based on the accelerated solvent extraction (ASE) and in cell clean-up technique was developed and successfully coupled with gas chromatography-mass spectrometry (GC/MS) for the analysis of musks in sediment samples. With this method, the limits of detection as low as 0.03–0.05?ng?g?1 and the recovery rate of 86.0%–104% are achieved. When compared with soxhlet extraction (SE) and ultrasonic extraction (USE), ASE not only has the best extraction efficiency but also has advantage in extraction time and solvent consumption. Eight synthetic musks, including six polycyclic musks (Tonalide (AHTN), Galaxolide (HHCB), Phantolide (AHDI), Traseolide (ATII), Cashmeran (DPMI) and Celestolide (ADBI)) and two nitro musks (musk xylene (MX) and musk ketone (MK)), were evaluated in sediment samples collected from 15 selected locations of the Taihu lake, one of the largest freshwater lakes in China. The contents of synthetic musks in sediment samples range from 0.336 to 3.10?ng?g?1 for HHCB, 0.184 to 1.21?ng?g?1 for AHTN, below detection limit (BDL) to 0.349?ng?g?1 for MX, and BDL to 0.0786?ng?g?1 for MK. The contents of DPMI, ADBI, AHMI and ATII are below detection limit in all samples. The results reflect current status of fragrance compound pollution in this area, and provide basic data for environmental policy making.  相似文献   

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