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991.
提出了高效液相色谱法测定全血中直链烷基苯磺酸钠同系物的含量。全血样品用酸性提取溶液稀释,过Bakerbond SPE C18固相萃取小柱,经甲醇-乙酸-水(49+2+49)混合溶液淋洗后用甲醇-氨水(98+2)混合溶液洗脱。经纯化后的洗脱液在Wakopak WS AS-Aqua(250 mm×4.6 mm,5μm)柱上进行分离,流动相为乙腈与水(60+40)混合溶液,检测波长为228 nm。5种n-ABS同系物的C10~C14的质量分数在10.0~100.0 ng.g-1范围内与其峰面积呈线性关系,全血中各同系物回收率为78%~107%;日内相对标准偏差(n=5)≤10%,日间相对标准偏差(n=5)≤13%。 相似文献
992.
采用溶剂浮选法分离富集鬼箭羽提取液中黄酮类化合物,并利用紫外可见分光光度法和高效液相色谱法对总黄酮及槲皮素的含量作了测定。黄酮类化合物最佳浮选条件为浮选溶剂正丁醇,溶液pH为3.0,氮气流量300 mL·min~(-1),浮选时间50 min。该法运用于鬼箭羽中黄酮化合物的分离富集,总黄酮浮选效率在70.8%~75.0%之间,浮选液旋干后总黄酮的含量是药材提取液旋干后的4.6倍;通过高效液相色谱法研究了以槲皮素为目标物的纯化分离效果,并测定其中槲皮素的含量,结果显示槲皮素浮选效率在88.9%~92.2%之间,浮选液旋干后槲皮素的含量是药材提取液旋干后的5.7倍。 相似文献
993.
Schiff碱类锌(Ⅱ)配合物的合成、晶体结构及发光性能 总被引:4,自引:0,他引:4
本文合成了2个新的Schiff碱锌配合物Zn(C13H10NO)2(1)和Zn(C14H12NO)2(2),测定了它们的晶体结构。结果表明,配合物1属三斜晶系,空间群P1,晶胞参数a=0.9495(2)nm,b=1.0758(2)nm,c=1.2343(3)nm,α=68.318(2)°,β=67.882(3)°,γ=78.316(3)°,V=1.0824(4)nm3,Z=2,Dc=1.405Mg·m-3,F(000)=472,μ=1.160mm-1;配合物2属单斜晶系,空间群C2/c,晶胞参数a=2.1845(5)nm,b=0.87905(19)nm,c=1.1988(3)nm,β=96.563(3)°,V=2.2870(9)nm3,Z=4,Dc=1.411Mg·m-3,F(400)=1008,μ=1.102mm-1。研究了它们在甲醇、乙醇溶液中的发光行为,结果表明这两个配合物在溶液中发光为金属离子微扰下配体的n-π*的发光。 相似文献
994.
合成了间氨基酚修饰超高交联吸附树脂(MMAR)。用红外光谱等进行表征,并用于吸附水溶液中2-氨基吡啶的研究。热力学研究结果表明,Freundlich吸附等温方程能够对静态吸附等温线进行很好的拟合。吸附焓变ΔH0,其绝对值小于46 KJ.mo-l1,表明以物理吸附为主以及该吸附剂容易脱附的特征;△G0,说明吸附是自发行为;△S0,表明吸附质分子在树脂表面上的运动受到了限制。动力学研究结果表明,吸附符合一级动力学方程,吸附速率随着温度的升高而增大,颗粒内扩散是速率控制步骤之一。表观活化能Ea10 KJ.mo-l1,说明吸附较容易进行。 相似文献
995.
实验发现,3,4-二羟基苯甲酸与铈(Ⅳ)在酸性介质中产生弱化学发光反应,奎宁存在能增强此发光,由此建立了化学发光法测定微量3,4-二羟基苯甲酸的新方法。该方法的线性范围为8.0×10-7~1.0×10-4mol/L,检出限为5.0×10-8,对8.0×10-6mol/L的3,4-二羟基苯甲酸进行11次测定的相对偏差为3.0%。该法应用于测定汉江水中加入的3,4-二羟基苯甲酸,结果令人满意。 相似文献
996.
997.
An electrochemical biosensor for mimicking the metal-mediated DNA damage pathway in situ was presented. The Fenton reagents (H2O2 and iron ion) for the DNA damage were generated in situ with a constant rate from the sensing film. H2O2 and iron ion reacted further together to yield hydroxyl radical, which attacked DNA in the film. These courses of DNA damage were just like those happened in organism. The DNA damage was detected by monitoring the differential pulse voltammetric response of an electrochemical indicator, Co(phen)33+. Another electrochemical indicator, Ru(NH3)63+, was also used for monitoring the DNA damage as a complementary means and the minimal detectable amount of DNA damage was 0.16 μg. The biosensor had good reproducibility. After this biosensor was used for 11 times, 90% of the first detection signal was obtained. 相似文献
998.
Xiaopeng Jiao 《Journal of solid state chemistry》2010,183(7):1697-1703
Boron reacted with ball milled boron oxide under pressures between 1 and 5 GPa and at temperatures between 1300 and 1700 °C to afford boron suboxide (B6O). Icosahedral B6O grains with diameters ranging from 100 nm to 1.3 μm were prepared. The factors that affect the synthesis of B6O are investigated. The best sample with crystal size up to 1.3 μm is obtained at 2 GPa and 1400 °C for 6 h. The indentation experiment gave an average Vickers hardness of 32.3 GPa for bulk B6O sample, which is consistent with previous reports. Bulk B6O sample exhibits oxidation resistance in air up to 1000 °C and mild oxidation in the temperatures of 1000-1200 °C, which is more oxidation resistant than diamond. It is possible that B6O could be used as a substitute for diamond in industry because of its relatively mild synthesis conditions, high thermal stability and high hardness. 相似文献
999.
Zong‐Wei Xuan Xiao‐Ying Sun Guo‐Song Jiao Zi‐Qin Zhai Wei Sun Lu‐De Lu 《中国化学会会志》2010,57(6):1262-1267
A new carbon ionic liquid paste bioelectrode was fabricated by mixing hemoglobin (Hb) with graphite powder, ionic liquid 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMIMBF4) and liquid paraffin homogeneously. Nafion film was cast on the electrode surface to improve the stability of bioelectrode. Direct electrochemistry of Hb in the bioelectrode was carefully investigated. Cyclic voltammetric results indicated that a pair of well‐defined and quasi‐reversible electrochemical responses appeared in pH 7.0 phosphate buffer solution (PBS), indicating that direct electron transfer of Hb was realized in the modified electrode. The formal potential (E0′) was calculated as ?0.316 V (vs. SCE), which was the typical characteristic of the electrochemical reaction of heme Fe(III)/Fe(II) redox couple. Based on the cyclic voltammetric results the electrochemical parameters of the electrode reaction were calculated. This bioelectrode showed high electrocatalytic activity towards the reduction of trichloroacetic acid (TCA) with good stability and reproducibility. 相似文献
1000.
Yan Lu Yong Wang Yuqin Zou Zheng Jiao Bing Zhao Yaqin He Minghong Wu 《Electrochemistry communications》2010,12(1):101-105
This paper reports the microwave-assisted synthesis of Co3O4 nanomaterials with different morphologies including nanoparticles, rod-like nanoclusters and macroporous platelets. The new macroporous platelet-like Co3O4 morphology was found to be the best suitable for reversible lithium storage properties. It displayed superior cycling performances than nanoparticles and rod-like nanoclusters. More interestingly, excellent high rate capabilities (811 mAh g?1 at 1780 mA g?1 and 746 mAh g?1 at 4450 mA g?1) were observed for macroporous Co3O4 platelet. The good electrochemical performance could be attributed to the unique macroporous platelet structure of Co3O4 materials. 相似文献