共查询到20条相似文献,搜索用时 187 毫秒
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新席夫碱3,5-二溴水杨醛缩邻氨基酚的合成及荧光熄灭法测定痕量铝的研究 总被引:3,自引:0,他引:3
基于Al(Ⅲ)与3,5-二溴水杨醛缩邻氨基酚(简称BSAP)和溴化十六烷基三甲胺(CTMAB)形成络合物导致体系荧光熄灭的特性,提出了一种测定痕量Al(Ⅲ)的新荧光方法。在pH3.8~4.5的醋酸铵缓冲介质和CTMAB存在下,Al(Ⅲ)与BSAP形成1:1的络合物。在λex=355nm、λem=535nm的条件下,体系产生的荧光熄灭程度最大,铝量的线性范围为0~0.8αg/25mL,检测限为0.25ug/mL。方法用于水样、合金钢及抗静电油剂中铝的测定,结果满意。 相似文献
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合成了新荧光试剂5-(4'-氯-2'-羧基苯基偶氮)罗丹宁(CRACP)。以元素分析、红外吸收光谱、核磁共振谱和质谱确定了其结构。试剂在pH5.0~5.4时,与Cu(Ⅱ)形成稳定的荧光螯合物,且在λem/λex=408nm/310nm产生强荧光。其荧光强度与Cu(Ⅱ)的浓度在0.1~0.9μg/10mL范围内呈线性关系。检测限为0.5ng/g。已用于痕量Cu(Ⅱ)的荧光分光光度法测定。测定了茶叶中 相似文献
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7—(苯偶氮)—8—羟基喹啉—5—磺酸钠光度法测定铝 总被引:1,自引:0,他引:1
研究了7-(苯偶氮)-8-羟基喹啉-5-磺酸钠光度法测定铝(Ⅲ)的实验条件及反应机理。该显色剂在PH4.2水溶液中呈红色,λmax=520nm,与铝(Ⅲ)形成配合物呈黄色。其配合比为1:3,最大吸收峰为λmax=435nm。 相似文献
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报道了新荧光试剂3-苯基-5-(4′-硝基-2′-羧基苯偶氮)-2-硫代-4-噻唑啉酮(3P-4NRACP)的合成,通过元素分析、红外光谱、核磁共振谱及质谱确证了其结构。在pH5.6时,它与铜(Ⅱ)形成稳定的荧光螫合物,在γex/λem=305nm/405nm处产生强荧光,其荧光强度与铜(Ⅱ)的浓度在1.57×10-10~1.89×10-8mol/25mL范围内呈线性关系,灵敏度达1.57×10-10mol/g的铜(Ⅱ)。用此方法测定了杂交米、糯米及香米中的痕量铜(Ⅱ),结果满意。 相似文献
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试剂7—(8‘—羟基喹啉偶氮)—8—羟基喹啉—5—磺酸荧光光度法测定镁(II)… 总被引:1,自引:0,他引:1
新合成了试剂7-(8'-羟基喹啉偶氮)-8-羟基喹啉-5-磺酸(简称8QA8Q5S),并对其进行结构鉴定,研究了试剂荧光光度法测定镁的反应条件。镁与试剂在pH10.30氨水/氯化铵缓冲介质中形成2:1的络合物并呈现荧光,其λex/λem=260/488(nm),线性范围为0 ̄12μg/25mL,检测限为3.12ppb,考察了共存离子的干扰,并直接应用于合金样中镁的测量,结果满意。 相似文献
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松香中铝的分析方法的研究 总被引:2,自引:0,他引:2
研究了在乙醇有机相中,用分光光度法直接测定松香中的铝。结果表明,在PH5左右的乙酸-乙酸铵缓冲溶液中,铝试剂与松香中的铝在乙醇溶液中形成红色络合物,在525nm波长处有最大吸收,表观摩尔吸光系数ε=1.35*10^4,铝浓度在0-50μg/范围内符合比尔定律。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献