Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Cavity enhanced liquid-phase stopped-flow kinetics
Analyst ( IF 3.6 ) Pub Date : 2017-12-19 00:00:00 , DOI: 10.1039/c7an01823a Zuzana Bajuszova 1, 2, 3, 4 , Hanan Naif 1, 2, 3, 4 , Zulfiqur Ali 1, 2, 3, 4 , Joseph McGinnis 1, 2, 3, 4 , Meez Islam 1, 2, 3, 4
Analyst ( IF 3.6 ) Pub Date : 2017-12-19 00:00:00 , DOI: 10.1039/c7an01823a Zuzana Bajuszova 1, 2, 3, 4 , Hanan Naif 1, 2, 3, 4 , Zulfiqur Ali 1, 2, 3, 4 , Joseph McGinnis 1, 2, 3, 4 , Meez Islam 1, 2, 3, 4
Affiliation
|
The first application of liquid-phase broadband cavity enhanced spectroscopy (BBCEAS) to the measurement of stopped-flow kinetics is reported. The stopped-flow technique is widely used for the study of the kinetics of fast liquid-phase reactions down to millisecond timescales. UV-visible absorption spectroscopy is commonly used as the detection method. Increased sensitivity can potentially allow reactions which are too fast to be measured, to be studied by slowing down the reaction rate through the use of lower concentration of reactants. A simple low cost BBCEAS experimental setup was coupled to a commercial stopped-flow instrument. Comparative standard absorption measurements were also made using a UV-visible double-beam spectrometer as the detector. Measurements were made on the reaction of potassium ferricyanide with sodium ascorbate under pseudo-first order conditions at pH 8 and pH 9.2 A cavity enhancement factor (CEF) of 78 at 434 nm was obtained whilst the minimum detectable change in the absorption coefficient αmin(t), was 1.35 × 10−5 cm−1 Hz−1/2. The kinetic data at pH 9.2 was too fast to be measured using conventional spectroscopy, whilst the BBCEAS measurements allowed 30 fold lower concentration of reactants to be used which slowed down the reaction rate enough to allow the rate constant to be determined. The BBCEAS results showed a 58 fold improvement in sensitivity over the conventional measurements and also compared favourably with the relatively few previous liquid-phase cavity enhanced kinetic studies which have been performed using significantly more complex and expensive experimental setups.
中文翻译：
腔增强液相停流动力学
报道了液相宽带腔增强光谱法（BBCEAS）在停止流动力学测量中的首次应用。停止流技术被广泛用于研究毫秒级以下快速液相反应的动力学。紫外可见吸收光谱法通常用作检测方法。灵敏度的提高可能潜在地允许通过使用较低浓度的反应物降低反应速率来研究太快而无法测量的反应。一个简单的低成本BBCEAS实验装置与一台商用停流仪器相连。还使用紫外线可见双光束光谱仪作为检测器进行了比较标准吸收率测量。α分钟（吨），为1.35×10 -5厘米-1赫兹-1/2。pH 9.2下的动力学数据太快，无法使用常规光谱法进行测量，而BBCEAS测量允许使用的反应物浓度降低30倍，这减慢了反应速度，足以确定速度常数。BBCEAS结果显示灵敏度比常规测量提高了58倍，并且与使用相对复杂得多且昂贵的实验装置进行的相对较少的先前液相腔增强动力学研究相比较也很有利。
更新日期：2017-12-19
中文翻译：
腔增强液相停流动力学
报道了液相宽带腔增强光谱法（BBCEAS）在停止流动力学测量中的首次应用。停止流技术被广泛用于研究毫秒级以下快速液相反应的动力学。紫外可见吸收光谱法通常用作检测方法。灵敏度的提高可能潜在地允许通过使用较低浓度的反应物降低反应速率来研究太快而无法测量的反应。一个简单的低成本BBCEAS实验装置与一台商用停流仪器相连。还使用紫外线可见双光束光谱仪作为检测器进行了比较标准吸收率测量。α分钟（吨），为1.35×10 -5厘米-1赫兹-1/2。pH 9.2下的动力学数据太快，无法使用常规光谱法进行测量，而BBCEAS测量允许使用的反应物浓度降低30倍，这减慢了反应速度，足以确定速度常数。BBCEAS结果显示灵敏度比常规测量提高了58倍，并且与使用相对复杂得多且昂贵的实验装置进行的相对较少的先前液相腔增强动力学研究相比较也很有利。
京公网安备 11010802027423号