Track-etched membrane-based dual-electrode coulometric detector for microbore/capillary high-performance liquid chromatography
Track-etched membrane-based dual-electrode coulometric detector for microbore/capillary high-performance liquid chromatography
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DOI：
10.1016/j.aca.2019.12.045
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发表时间：
2020-03-15
影响因子：
6.2
通讯作者：
Takayanagi，Toshio
中科院分区：
文献类型：
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作者：
Mizuguchi，Hitoshi;Nishimori，Daichi;Takayanagi，Toshio
将该电化学流动池应用于微柱/毛细管双电极库仑检测器中，实现了小进样量、低洗脱液流速的高效液相色谱分析。所提出的流动池具有0.1 mm直径的入口通道，每个电极的检测体积为0.08 nL，这是由流过电极的洗脱液确定的。对于双电极检测器，计算的体积为0.24 nL。抗坏血酸的电氧化效率随着流速的降低而增加，当流速低于50 μL min−1时，其接近100%，这是微孔或毛细管液相色谱中常见的流速。儿茶酚胺，如去甲肾上腺素，肾上腺素和多巴胺，检测总转换与两个电子氧化的电位范围从0.8至1.0 V与银/氯化银分离后，与微孔柱。这些峰伴随着相应的阴极峰，来自准稳定的电氧化产物的儿茶酚胺。去甲肾上腺素、肾上腺素和多巴胺的检测限分别为0.1、0.1和0.2 μM。5.0 μM这些化合物5次重复测定的RSD值分别为0.9%、0.7%和1.5%。库仑检测也证明了药物中的儿茶酚胺的测定。
The electrochemical flow cell containing track-etched microporous membrane electrodes was applied to a dual-electrode coulometric detector for microbore/capillary HPLC with a small injection volume and low eluent flow rate. The proposed flow cell with a 0.1-mm diameter inlet channel gave a detection volume of 0.08 nL per electrode, which was determined by the eluent flow through the electrode. For the dual-electrode detector, the calculated volume was 0.24 nL. The efficiency of electrooxidation ofl-ascorbic acid increased as the flow rate decreased and was close to 100% when the flow rate was below 50 μL min−1, which is a common flow rate in microbore or capillary liquid chromatography. Catecholamines, such as noradrenaline, adrenaline, and dopamine, were detected by total conversion with two-electron oxidation in the potential range from 0.8 to 1.0 V vs. Ag/AgCl after separation with a microbore column. These peaks were accompanied by corresponding cathodic peaks derived from quasi-stable electrooxidation products of the catecholamines. The detection limits of noradrenaline, adrenaline, and dopamine were 0.1, 0.1, and 0.2 μM, respectively. The RSD values for five replicate measurements of 5.0 μM of these compounds were 0.9%, 0.7%, and 1.5%, respectively. Coulometric detection was also demonstrated by determination of catecholamines in pharmaceuticals.