測定井水和河水中鉛、鎘和坤的方法之研究

A Study on the Methods for the Determination of Lead, Cadmium, and Arsenic in Well Water and River Water

蕭家寧(Chia-Ning Shiao) ； 郭茂松(Mao-Sung Kuo) ； 顏春蘭(Vanda-Orchio Yen) ； 蔡惠澤(Hui-Tuh Tsai)

《化學》 45卷1期 (1987/03) Pp. 15-22

https://doi.org/10.6623/chem.1987003

摘要

本篇以石墨電熱式原子吸光法(Graphite Furnace Atomic Absorption Spectrophotometry)和汞滴差波剝除伏安法(Differential Pulse Anodic or Cathodic Stripping Voltammetry at Hanging Mercury Drop Electrode)測定井水和河川水樣中的鉛、鎘和砷。除了用剝除伏安法測砷時，需要前處理，使As(V)還原爲As(II)外，其餘都可直接測得。此兩種方法所得的結果都很靠近(相差在1 ppb以內)，但精密度(Precision)則以石墨式原子吸光法的較好些。它們的線性範圍和偵測極限(Detection Limit)也都很相近。在測鉛、鎘、砷時，石墨式原子吸光法可分別測到0.68 ppb, 0.031 ppb,1.39 ppb；剝除伏安法則可分別測到0.50ppb, 0.30ppb, 0.99ppb。剝除伏安法的優點是可同時測得鉛和鎘，每次約需七分鐘，而石墨式原子吸光法每次只能測一種元素，但只需二分鐘。石墨式原子吸光法的優點是每次水樣只需用20 μL，而剝除伏安法則需9 mL。在測砷時，以石墨式原子吸光法較方便，因不需前處理的步驟。

並列摘要

Two methods, GF-AAS (Graphite Furnace Atomic Absorption Spectrophotometry) and DP-ASV or DP-CSV (Differential Pulse Anodic or Cathodic Stripping Voltammetry at Hanging Mercury Drop Electrode). were studied to determine Pb, Cd, and As in a well water and some river water. Water samples which contain low-ppb ranges of Pb, Cd, and As could be determined directly by GF-AAS and DP-ASV without any pre-treatment or pre-concentration except for the determination of As by use of DP-CSV. The results obtained by use of GF-AAS and DP-ASV are comparable (within 1 ppb) but GF-AAS has a better precision than that of DP-ASV or DP-CSV. The ranges of linearity by GF-AAS and DP-ASV or DP-CSV are also comparable. The detection limits for Pb, Cd, and As are 0.68 ppb, 0.031 ppb, and 1.39 ppb, respectively , by use of GF-AAS and are 0.50 ppb, 0. 30 ppb, and 0.99 ppb, respectively, by use of DP-ASV and DP-CSV. Thu advantage for DP-ASV is that both Pb and Cd can be determined simultaneously in one run although it took about 7 minutes, while GF-AAS can determine only one element at a time and took about 2 minutes. The advantage for GF-AAS is that only 20 L of sample volume is used while DP-ASV and DP-CSV need 9 mL. For the determination of As, GF-AAS is simpler because the pre-treatment is not necessary.