以固相萃取結合螢光光譜法檢測茶湯中微量硒的方法開發

Method development of trace amount selenium determination in tea soup by solid phase extraction combined with fluorescence spectrometry

蔡哲豪(CHE-HAO TSAI)

指導教授 ： 陳政男

朝陽科技大學/理工學院/應用化學系/碩士(2020年)

摘要

硒是人體不可或缺的微量元素，衛生署公告每日建議攝取量為55微克，每日上限攝取量為400微克，硒攝取量過多或太少都會對人體造成危害。茶是日常生活的重要飲品之一，文獻中提到茶葉亦含有微量硒，然而鮮少有研究探討茶湯中的硒含量，過去檢測硒的方法需使用高效能液相層析結合感應耦合電漿質譜儀進行分析，儀器檢測成本較高。
本研究以正己烷取代毒化物環己烷，作為2,3-二氨基萘(DAN)前處理的萃取溶劑，並使用標準添加法結合自製C18固相萃取管柱對硒衍生物4,5-苯並苤硒腦(BPS)進行預濃縮，再以少量的環己烷沖提，於螢光光譜儀檢測茶湯中硒溶出量。富硒綠茶葉及茶粉沖泡之茶湯樣品同日間(intra-day)檢測結果分別為170.5 ± 1.9 ppb及802.7 ± 8.1 ppb；異日間(inter-day)檢測結果分別為148.2 ± 11.4 ppb及770.3 ± 28.5 ppb。另外對市售紅茶包進行異日間實驗，其檢測結果為212.0 ± 17.3 ppb，所有茶湯樣品檢測結果之RSD均小於0.1%。所使用之自製C18固相萃取管柱能重複檢測80次以上，只需要1 mL環己烷即可完成一次檢測，能大幅降低98%環己烷使用量，偵測極限可降低至0.2 ppb，成功建立一種低毒性、低成本、環保、高靈敏度且具有可重複利用性的固相萃取技術。

關鍵字

硒 ； 茶葉 ； 固相萃取

並列摘要

Selenium is a trace element in the human body. Too much or too little selenium intake will cause harm to the human body. The Department of Health announcement the RDA and UL of selenium is 55 µg and 400 µg. Tea is one of the important drinks in daily life. It is mentioned in the literature that tea also contains trace amounts of selenium. However, few studies have explored the selenium content in tea soup. In the past, methods for detecting selenium required HPLC-ICP-MS for analysis, the cost of instrument detection is higher.
In this study, n-hexane was used to replace the toxic compound cyclohexane as the preparation solvent of 2,3-diaminonaphthalene (DAN), and the self-made C18 column was to preconcentrated selenium derivatives 4,5-benzopiaselenol (BPS), then elution with a small amount of cyclohexane, following the measurement by a fluorescence spectrometer. The standard addition method was applied to remove the matrix effect.. Intra-day test results of selenium-enriched green tea leaves and tea powder brewed tea soup samples were 170.5±1.9 ppb and 802.7±8.1 ppb respectively; inter-day test results were 148.2±11.4 ppb and 770.3±28.5 ppb. In addition, the commercial black tea bags were tested in different days, and the test result was 212.0±17.3 ppb. The RSD of all tea soup samples was less than 0.1%. The self-made C18 solid phase extraction column can be repeatedly uesd more than 80 times. Only 1 mL of cyclohexane was needed to complete a test, which can greatly reduce the amount of cyclohexane consume by 98%. LOD can achieve to 0.2 ppb, and successfully establish a low toxicity, low cost, environmentally friendly, highly sensitive and reusable solid phase extraction technology.

並列關鍵字

Selenium ； Tea ； SPE

參考文獻

1. Silva, E. N., Aureli, F., Amato, M., Raggi, A., Cadore, S., Cubadda, F., ‘‘Selenium bioaccessibility and speciation in selenium-enriched lettuce: investigation of the selenocompounds liberated after in vitro simulated human digestion using two-dimensional HPLC-ICP-MS,’’ J. Agric. Food Chem. Vol. 65, pp. 3031-3038 (2017).

2. Colangelo, L. A., He, K., Whooley, M. A., Daviglus, M. L., Morris, S., Kiang Liu ‘‘Selenium exposure and depressive symptoms: The Coronary Artery Risk Development in Young Adults Trace Element Study,’’ NeuroToxicology, Vol. 41, pp. 167-174 (2014).

3. Zhang, N., Fu, N., Fang, Z. T., Feng, Y. H., Ke, L., ‘‘Simultaneous multi-channel hydride generation atomic fluorescence spectrometry determination of arsenic, bismuth, tellurium and selenium in tea leaves,’’ Food Chemistry, Vol. 124, pp. 1185-1188 (2011).

4. 何菊梅，「硒與運動」，嘉興學院體軍部，浙江 (2008)。

5. Hall, J. O., ‘‘CHAPTER 34 – Selenium,’’ Veterinary Toxicology, pp. 453-460 (2007).