- 學位論文
氯離子選擇薄膜電極之開發與生活環境水樣氯離子之分析
Development of chloride ion-selective membrane electrode and the analysis of chloride ion in living environmental water sample
摘要
本研究針對環境中水樣品之氯離子分析發展一種電化學電位式感測器。即以氯離子交換樹脂取代傳統氯離子交換劑，製作一種新的氯離子選擇薄膜電極，其薄膜組成成份:氯離子選擇物μ-4,5-二甲基-3,6-雙十二烷氧基-1,2-鄰苯二氯化汞、三甲基乙烯基四級氨鹽氯離子交換聚苯乙烯-二乙烯基苯樹脂、癸二酸二-2-乙基己酯塑化劑及聚氯乙烯高分子薄膜基材。此薄膜電極的氯離子標準品感測靈敏度於25℃為59.2 mV/pCl，符合能斯特方程式中的感應電位係數，偵測極限值為2.48 ppm，氯離子檢量線的濃度線性範圍為3.6-400.1 ppm (r2 = 0.9930)，電極達穩定感應所需平衡時間為10秒，在10℃到45℃之間其標準品添加檢量線斜率值(靈敏度)也皆與能斯特方程式理論值相符合，電極使用壽命可長達70天，於此期間電極均能保持前述之效能。本研究製作之氯離子選擇薄膜電極感測器亦已應用於地下水、自來水、石門水庫庫水及雨水中氯離子含量的檢測，分別測得氯離子含量為20.7 ± 0.5 ppm (RSD = 2.4％, n = 5)、9.5 ± 0.4 ppm (RSD = 4.2％, n = 5)、13.2 ± 0.4 ppm (RSD = 3.0％, n = 5)及4.5 ± 0.2 ppm (RSD = 4.6％, n = 5)，而分析的準確度為92％-95％之間。此四種水樣品也分別使用高效液相離子交換層析方法量測氯離子濃度，量測到地下水為20.9 ± 0.1 ppm (RSD = 0.5％, n = 4)、自來水為9.9 ± 0.1 ppm (RSD = 0.5％, n = 4)、石門水庫庫水為12.9 ± 0.1 ppm (RSD = 0.8％, n = 4)及雨水為4.6 ± 0.1 ppm (RSD = 0.7％, n = 4)。此兩種分析方法的定量結果，利用t-test比較後並未發現有顯著的差異，證明本研究氯離子選擇薄膜電極的水樣中氯離子分析是值得信賴的，且具有感測快速、靈敏、精確、及使用壽命長之優點。
並列摘要
In this study, a new type of chloride ion-selective electrode (ISE) was developed by substituting the traditional chloride ion-exchange reagent with a chloride ion-exchange resin to form an electrochemical potentiometric sensor for the analysis of chloride ion in environmental water samples. The composition of the membrane was composed of {μ-[4,5-Dimethyl-3,6-bis(dodecyloxy)-1,2-phenylene]}bis(mercury chloride) (ETH9033) as the ionophore, a trimethyl ethenyl quaternary ammonium chloride ion-exchange polystyrene divinylbenzene (TEQAC PSDVB) resin as the ion-exchanger, bis(2-ethylhexyl) sebacate (DOS) as the plasticizer, and polyvinylchloride (PVC) as the polymer membrane material. At temperature 25℃, the chloride ion-selective membrane electrode exhibited an ideal Nernstian response of 59.2 mV per decade to chloride ion standard solution in the linear calibration concentration range from 3.6 to 400.1 ppm (r2 = 0.9930) which showed a limit of detection (LOD) of 2.48 ppm and a response time less than 10 seconds. The slope (sensitivity) of the standard addition calibration curves is also consistent with the theoretical value of Nernstian equation in the temperature range from 10℃ to 45℃. The chloride ion-selective membrane electrode can be used continuously for a period of 70 days that still maintains the same performance as described previously. The developed chloride ISE was used to determine the concentration of chloride ion in ground water (20.7 ± 0.5 ppm, RSD = 2.4％, n = 5), tap water (9.5 ± 0.4 ppm, RSD = 4.2％, n = 5), Shihmen dam water (13.2 ± 0.4 ppm, RSD = 3.0％, n = 5), and rain water (4.5 ± 0.2 ppm, RSD = 4.6％, n = 5). The spike experiments showed the analysis accuracy for water samples was in the range of 92％-95％. The concentration of chloride ion in the four kinds of water sample were also measured by using the high-performance liquid ion-exchange chromatography (HPLC) method. The concentration of the chloride ion was 20.9 ± 0.1 ppm (RSD = 0.5％, n = 4), 9.9 ± 0.1 ppm (RSD = 0.5％, n = 4), 12.9 ± 0.1 ppm (RSD = 0.8％, n = 4), 4.6 ± 0.1 ppm (RSD = 0.7％, n = 4) for ground water, tap water, Shihmen dam water, and rain water, respectively. Then, the results obtained from the two analytical methods were compared with t-test that shows no significant difference between the two analytical methods. The comparison result proves that the ISME was reliable for the analysis of chloride ion in water samples. The developed chloride ISME also shows the advantages of fast response, sensitive, precise, accurate, and life-time.