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1.
通过HgX2(X=I,Br)与4,4’-二吡啶基二硫化物(dpds)在乙腈中的溶剂热反应,得到二个含1-(4-吡啶基)-吡啶铵-4-硫醇盐(ppt)的一维配位聚合物:[Hg2I4(ppt)]n(1)和[Hg2Br4(ppt)]n(2).在化合物1和2结构中ppt配体是由dpds在溶剂热反应条件下通过dpds的S—S键和S—C键切断然后进行重排在原位形成的.化合物1具有非中心对称的一维Z字型链状结构,化合物2则具有中心对称的一维Z字型链状结构.用飞秒简并四波混频法测定了1和2溶液的三阶非线性光学性质,化合物1具有较强的非线性光学响应,而化合物2却没有非线性光学响应,这种性质的差异可能由于碘离子是较溴离子更好的电子授体,化合物1有较小的HOMO-LUMO能级,更易发生电子在体系间跃迁,更有效使用三线激发态吸收. 相似文献
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通过HgX2 (X=I,Br)与4,4’-二吡啶基二硫化物(dpds)在乙腈中的溶剂热反应,得到二个含1-(4-吡啶基)-吡啶铵-4-硫醇盐(ppt)的-维配位聚合物:[Hg2I4(ppt)]n(1)和[Hg2Br4(ppt)]n(2).在化合物1和2结构中ppt配体是由dpds在溶剂热反应条件下通过dpds的S-S键和S-C键切断然后进行重排在原位形成的.化合物1具有非中心对称的-维Z字型链状结构,化合物2则具有中心对称的-维Z字型链状结构.用飞秒简并四波混频法测定了1和2溶液的三阶非线性光学性质,化合物1具有较强的非线性光学响应,而化合物2却没有非线性光学响应,这种性质的差异可能由于碘离子是较溴离子更好的电子授体,化合物1有较小的HOMO-LUMO能级,更易发生电子在体系间跃迁,更有效使用三线激发态吸收. 相似文献
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混合离子液体(N-丁基吡啶六氟磷酸盐,[BuPy][PF6])与石墨粉,制备了离子液体碳糊电极(CILE),再采用电沉积法制得PB/Au/CILE修饰电极,研究了该修饰电极的电化学行为及其对H2O2的电催化,建立了H2O2的计时安培测定新方法。结果表明:在该修饰电极上PB产生了一对准可逆的氧化还原峰,并对H2O2表现出良好电催化作用,安培法测定H2O2的线性范围为5.0×10-6~1.55×10-4mol/L,检出限为1.0×10-6mol/L(S/N=3)。连续10次测定5.0×10-6mol/L H2O2峰电流的RSD为2.1%。 相似文献
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离子液体双水相体系萃取分离牛血清白蛋白 总被引:36,自引:0,他引:36
建立了由亲水性离子液体四氟硼酸1-甲基-3-丁基咪唑([Bmim]BF4)和KH2PO4形成的双水相体系萃取分离牛血清白蛋白(BSA)的新方法。研究了不同盐及盐的浓度、离子液体浓度以及蛋白质用量、溶液酸度、其它共存物质对双水相成相及BSA萃取率的影响,结果表明,磷酸二氢钾盐浓度为80g/L,离子液体浓度在160~240mL/L,BSA的浓度为30~50mg/L,溶液酸度在pH4~8范围,离子液体双水相体系对BSA有较高的萃取率。用加入不同类型表面活性剂探讨了离子液体与蛋白质之间的作用。 相似文献
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采用1-羧甲基-3-甲基咪唑氯化盐离子液体对钠化蒙脱土进行插层改性,然后用苯胺的盐酸溶液进行二次插层,以过硫酸铵为氧化剂,盐酸溶液为掺杂剂,使进入离子液体/蒙脱土(CMMIm/MMT)层间的苯胺(An)发生氧化聚合反应,制备了一种具有良好导电性的聚苯胺/离子液体/蒙脱土复合材料(PANI/CMMIm/MMT).用红外光谱、X-射线衍射,热重分析和DSC对样品进行了表征.结果表明当离子液体/蒙脱土用量为7.5%、盐酸浓度为1mol/L、过硫酸铵与苯胺的摩尔比为1∶1、0℃下反应6h时制备的PANI/CMMIm/MMT纳米复合材料电导率最高,达到了0.3S/cm,是相同条件下聚苯胺/钠化蒙脱土纳米复合材料电导率的2.5倍,聚苯胺的7.5倍. 相似文献
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Characterization of forced degradation products of ketorolac tromethamine using LC/ESI/Q/TOF/MS/MS and in silico toxicity prediction 下载免费PDF全文
Pradipbhai D. Kalariya B. Raju Roshan M. Borkar Deepak Namdev S. Gananadhamu Prajwal P. Nandekar Abhay T. Sangamwar R. Srinivas 《Journal of mass spectrometry : JMS》2014,49(5):380-391
Ketorolac, a nonsteroidal anti‐inflammatory drug, was subjected to forced degradation studies as per International Conference on Harmonization guidelines. A simple, rapid, precise, and accurate high‐performance liquid chromatography combined with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry (LC/ESI/Q/TOF/MS/MS) method has been developed for the identification and structural characterization of stressed degradation products of ketorolac. The drug was found to degrade in hydrolytic (acidic, basic, and neutral), photolytic (acidic, basic, and neutral solution), and thermal conditions, whereas the solid form of the drug was found to be stable under photolytic conditions. The method has shown adequate separation of ketorolac tromethamine and its degradation products on a Grace Smart C‐18 (250 mm × 4.6 mm i.d., 5 µm) column using 20 mM ammonium formate (pH = 3.2): acetonitrile as a mobile phase in gradient elution mode at a flow rate of 1.0 ml/min. A total of nine degradation products were identified and characterized by LC/ESI/MS/MS. The most probable mechanisms for the formation of degradation products have been proposed on the basis of a comparison of the fragmentation of the [M + H]+ ions of ketorolac and its degradation products. In silico toxicity of the drug and degradation products was investigated by using topkat and derek softwares. The method was validated in terms of specificity, linearity, accuracy, precision, and robustness as per International Conference on Harmonization guidelines. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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建立了一种用于海水中K+、Na+、Ca2+、Cl-同时快速、自动测定的流动注射离子选择电极自动方法(FI-ISE-M),优化了方法的最佳条件:总离子强度调节液(TISAB)的组成为0.3 mmol/L K+、6.0 mmol/L Na+、1.4 mmol/L Ca2+、21.0 mmol/L Cl-及pH8.0的80 mmol/L的tris-H3BO3缓冲溶液,其流量为1.25mL/min;每次测定的样品用量仅为160μL,载流流量为1.42 mL/min,混合盘管长度为30cm(I.D.0.5 mm)。本方法的分析速度为100样/h,相对标准偏差为2.0%(n=11),标准添加回收率为94.9%~104.3%,测定范围分别为1.0~8.0 mmol/L K+、50~290 mmol/L Na+、3.2~16.0 mmol/L Ca2+、70~430 mmol/LCl-。本方法已应用于反渗透海水淡化系统的水质检测。 相似文献
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分别通过浸渍法和共沉淀法制备了不同Ni负载量的Ni/Al2O3催化剂。考察了Ni负载量、制备方法以及反应温度对Ni/Al2O3催化甲烷裂解性能的影响。结果表明,在550℃,浸渍法制备的Ni/Al2O3催化剂,当Ni负载量为20%(质量分数)、Ni金属平均粒径为11.25 nm时,具有最佳的甲烷催化裂解效果,其每摩尔Ni的氢气产量和每克Ni碳产量分别为164 mol和15.30 g。催化剂制备方法对Ni/Al2O3甲烷催化裂解反应有显著影响,相同Ni负载量共沉淀法制备的Ni/Al2O3甲烷催化裂解总体效果要好于浸渍法制备的Ni/Al2O3,而且反应过程中生成的碳纤维较长,管径也较均一。550℃时,共沉淀法制备的Ni负载量为41.2%(质量分数)的Ni/Al2O3催化剂在反应至350 min时,仍保持着30%以上的转化率。 相似文献
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Abstract— The purpose of the study was to determine if aluminum phthalocyanine tetrasulfonate (A1PcS4 ) photodynamic therapy (PDT) induced the formation of micronuclei in vitro and whether micronuclei formation was dependent on fiuence or cell type. NIH-3T3 and EMT-6 monolayer cultures were incubated in AlPcS4 (0 or 1 μg/mL) for 24 h, received 0.0, 0.5,1.0 or 1.5 J/cm 2 of 675 nm light, then reincubated and harvested at either 24, 48 or 72 h. The micronucleus frequency was determined in binucleated cells using the cytochalasin-block method. Cytotoxicity was assessed by using the 3(4,5-dimenthylthiazoyl-2-yl)2,5(diphenyl-tetrazolium bromide) (MTT) method. The effect of treatment on cell cycle progression was determined by calculating a proliferative index.
Aluminum phthalocyanine tetrasulfonate PDT induced a fluence-dependent increase in the frequency of micro-nuclei in NIH-3T3 and EMT-6 cells. The maximal effect of PDT was obtained in both cell lines 24 h after treatment. NIH-3T3 and EMT-6 cells exposed to a low fiuence of 0.5 J/cm2 had a significantly lower number of micro-nuclei per cell 48 h following PDT treatment compared to the number of micronuclei per cell observed 24 h following treatment; however, when cells were exposed to a fluence (1.0 or 1.5 J/cm2 ) the number of micronuclei per cell did not diminish until 72 h after PDT treatment. The results obtained from the micronucleus assay paralleled those results obtained from the MTT assay. 相似文献
Aluminum phthalocyanine tetrasulfonate PDT induced a fluence-dependent increase in the frequency of micro-nuclei in NIH-3T3 and EMT-6 cells. The maximal effect of PDT was obtained in both cell lines 24 h after treatment. NIH-3T3 and EMT-6 cells exposed to a low fiuence of 0.5 J/cm
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Aguilera R Chapman TE Catlin DH 《Rapid communications in mass spectrometry : RCM》2000,14(23):2294-2299
A gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) method is described and validated for measurement of delta(13)C values of the acetate derivatives of urinary etiocholanolone and androsterone. The analysis was performed with only 2 mL of urine. The sample preparation consisted of deconjugation with beta-glucuronidase, solid phase extraction, and derivatization with acetic anhydride and pyridine. The within-assay precision of two quality control (QC) urine samples ranged from 0.5 to 2.1 CV%. The between-assay precision in the same QC urines ranged from 1.7 to 3.4 CV%. Administration of testosterone enanthate to a subject resulted in a 6 per thousand decrease in delta(13)C values from -25 per thousand (baseline) to -31 per thousand. Two weeks after testosterone administration was discontinued, the delta(13)C values remained abnormally low while the urine testosterone/epitestosterone (T/E) ratio returned to less than 6. This relatively simple method is useful for rapidly screening a large number of urine samples, including those with T/E <6. 相似文献
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Filot MS Leuenberger M Pazdur A Boettger T 《Rapid communications in mass spectrometry : RCM》2006,20(22):3337-3344
An improved method for the determination of deuterium-to-hydrogen (D/H) ratios of non-exchangeable hydrogen in cellulose is presented. The method is based on the equilibration reaction of the hydroxyl hydrogen of cellulose and water vapour of known isotopic composition. The equilibrated cellulose is pyrolysed and the total D/H ratio determined by subsequent online isotope ratio mass spectrometry (IRMS). With a mass balance system the D/H ratio of non-exchangeable hydrogen is recalculated after an empirical calibration has been performed, yielding a mean exchangeability of 0.239 and an equilibrium fractionation factor of 1.082 between the hydroxyl hydrogen of cellulose and water hydrogen at 110 degrees C. Equilibration takes 10 min per sample. Results obtained by this online equilibration method agree very well with values obtained by the nitration technique (R2 = 0.941). The uncertainty of the equilibration method is +/-4 per thousand resulting from a single standard deviation of +/-2.8 per thousand for the equilibration determined by standard cellulose and 2.8 per thousand from the variable exchangeability of the hydroxyl hydrogen in cellulose due to crystalline areas. The latter uncertainty may be lowered by minimising the crystallinity of the cellulose. Advantages of this new technique are (i) the considerably reduced sample amount required (as low as 0.2 mg, ideally 0.5 mg compared with 20 mg for the conventional nitration technique); (ii) an approximately 100-fold reduced process time; and (iii) no need for the hazardous chemicals used in the nitration technique. 相似文献
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Rhee TS Mak J Röckmann T Brenninkmeijer CA 《Rapid communications in mass spectrometry : RCM》2004,18(3):299-306
A convenient method is described for analyzing the deuterium/hydrogen (D/H) ratio of atmospheric molecular hydrogen (H(2)) based on mass spectrometric isotope-ratio monitoring. The method requires small amounts of air ( approximately 300 mL STP), is operated on-line, and comprises four steps: (1). the condensation of the air matrix at approximately 40 K; (2). the collection of the non-condensed components of the air sample (H(2), Ne, He, and traces of N(2)) in a 5 A molecular sieves pre-concentration trap at approximately 63 K; (3). gas chromatographic purification of H(2) in a flow of He; and (4) quantification of the D/H ratio in an isotope-ratio mass spectrometer. The precision of the determination of the D/H ratio is better than 2 per thousand, which is comparable to, or better than, that obtained by conventional duel-inlet off-line analysis. There are, however, discrepancies relative to the D/H ratios determined by conventional duel-inlet analysis. This is due to differences in peak shape between reference and sample air, depending on the amount of H(2) injected. Consequently, calibration runs are required. After the calibration of the system, we obtained an accuracy of 1.5 per thousand, so that the accumulated uncertainty is estimated to be less than 4 per thousand. The method also allows determination of the H(2) concentration, with an uncertainty estimated to be 2%. 相似文献
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The biodegradation of poly(3-hydroxybutyrate), P(3HB), and its copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate), P(3HB-co-3HV) produced by a locally isolated bacteria identified as Erwinia sp. USMI-20 were carried out by using soil burial test and immersion test method at various places under the tropical environment in West Sumatra, Indonesia. The isolation of P(3HA)-degrading microorganisms was done by the in vitro rapid plate test method and was further characterized by using biochemical reactions. Our results showed that P(3HB) biodegraded at a rate of 3.6% per week in activated sludge, 1.9% per week in soil, 1.5% per week in lake water and 0.8% per week in Indian Ocean sea water. The degradation rates for P(3HB-co-3HV) were 17.8% per week in activated sludge, 6.7% per week in soil, 3.2% per week in lake water and 2.7% per week in Indian Ocean sea water. The biodegradation of both polymers were highest after burial into activated sludge with a half-life (T1/2) of 14 weeks and the time for 100% degradation (T100%) of 28 weeks for P(3HB), and a T1/2 of 3 weeks and T100% at 6 weeks for P(3HB-co-3HV). In this study, 10 bacteria which were responsible for the biodegradation of P(3HB) and P(3HB-co-3HV) film were isolated and identified from the various places studied under the tropical environment. They were Bacillus sp. FAAC-2202, Enterobacter sp. FAAC-2207, Bacillus sp. FAAC-2209 and Proteus sp. FAAC-2203 obtained from activated sludge, Bacillus sp. FAAC-2201 and Alcaligenes sp. FAAC-2210 from soil, Alcaligenes sp. FAAC-2205, Micrococcus sp. FAAC-2206 and Pseudomonas sp. FAAC-2208 from lake water and Proteus sp. FAAC-2204 from Indian Ocean sea water. 相似文献
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Calderone G Naulet N Guillou C Reniero F Cortes AI 《Rapid communications in mass spectrometry : RCM》2005,19(5):701-705
A simple and rapid method to measure naturally occurring delta(13)C values of headspace CO(2) of sparkling drinks has been set up, using direct injections on a gas chromatograph coupled to an isotope ratio mass spectrometer, through a combustion interface (GC/C/IRMS). We tested the method on CO(2) gas from several origins. No significant isotopic fractionation was observed nor influences by secondary compounds eventually present in the gas phase. Standard deviation for these measurements was found to be <0.1 per thousand. 相似文献
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《Biomedical chromatography : BMC》2018,32(8)
A precise and accurate liquid chromatography–tandem mass spectrometric (LC–MS/MS) bioanalytical method has been developed and validated for the simultaneous quantification of zidebactam (ZID) and cefepime (FEP) in dog plasma. Ceftazidime was used as an internal standard. Protein precipitation method was used as sample preparation approach. The calibration curve obtained was linear (r ≥ 0.99) over the concentration range 0.156–80 μg/mL for ZID and 0.312–160 μg/mL for FEP. The method was validated as per US Food and Drug Administration guidelines and the results met the acceptance criteria. A run time of 3.5 min for each sample made it possible to analyze the maximum number of samples per day. The proposed method was successfully applied for pharmacokinetic study in beagle dogs. 相似文献