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Shiozawa A, Kojima Y, Kotani A, Machida K, Yamamoto K, Hakamata H. Electrochemical determination of emodin in acidic media by high-performance liquid chromatography and its application to Polygoni Multiflori Radix samples. ANAL SCI 2022; 38:1449-1454. [PMID: 35989408 DOI: 10.1007/s44211-022-00177-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 08/03/2022] [Indexed: 11/29/2022]
Abstract
Electrochemical reduction of emodin under acidic media occurs at a less negative potential when compared with that under neutral media. When emodin is electrochemically detected at a less negative potential, a decrease in background noise and improvement in specificity benefit the development of high-performance liquid chromatography with electrochemical detection (HPLC-ECD) for its determination. HPLC-ECD was performed using an octadecyl silica column, acetonitrile-water (60:40, v/v) containing 5 mmol L-1 hydrochloric acid and 10 mmol L-1 lithium perchlorate, as a mobile phase, and an applied potential at - 0.4 V vs. Ag/AgCl. Under these optimal HPLC-ECD conditions, the detection limit (signal-to-noise ratio, S/N = 3) of emodin was 0.61 μg L-1. When this HPLC-ECD system was applied to the determination of emodin in Polygoni Multiflori Radix (PMR) samples, other peaks did not appear close to the emodin peak on a chromatogram. The emodin contents in PMR samples were determined with relative standard deviations (RSDs, n = 6) of less than 3.9%, and their recoveries ranged from 92 to 106%. We have shown that our HPLC-ECD system performed an accurate, precise, and specific determination of emodin in PMR samples.
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Affiliation(s)
- Aya Shiozawa
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan
| | - Yusuke Kojima
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan
| | - Akira Kotani
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan.
| | - Koichi Machida
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan
| | - Kazuhiro Yamamoto
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan
| | - Hideki Hakamata
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan
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