利用瑞利光散射技術快速測定飲料和血清中微量鉀   全文下載

Rapid Determination of Trace Potassium in Drinks and Serum by Rayleigh Light Scattering Technique

本文探討一種靈敏、快速、選擇性好的瑞利光散射技術分析方法，用以測定飲料和血清中的微量鉀離子含量。鉀離子被轉化為四苯硼鉀微粒，而顯示強的瑞利散射光。文章詳細研究了檢測波長、酸度、穩定劑和共存離子對測定的影響。實驗確定了最佳分析條件，產生強的瑞利光散射信號：樣品溶液在乙酸-乙酸鈉緩衝體系中（0.50 m，pH = 8.0），加入0.5 ml之5.05 μm十二烷基苯磺酸鈉、1.0 ml之1.0%的四苯硼鈉溶液，最大檢測波長567 nm。鉀離子濃度在0.20-1.60 μg ml-1範圍，增強的瑞利散射光信號與鉀離子濃度成線性關係，最低檢測極限達到 0.10 μg ml-1。為了檢驗方法的可行性，用所建立的方法測定了礦泉水、純淨水、飲料和血清樣品中鉀離子濃度，測定結果與離子選擇性電極法一致。本方法的加標回收率較好，在95.10-107.02%之間。本文建立的方法測定微量鉀離子具有靈敏、快速和選擇性好的優點，高濃度的共存離子不干擾測定。

In this paper, a sensitive, rapid and selective method based on Rayleigh light scattering technique (RLS) was proposed for the determination of potassium using a conventional spectrofluorometer. Potassium was transformed to KB(C6H5)4 particles, which displayed intense light scattering in aqueous solutions. Effects of factors such as wavelength, acidity, ionic strength and coexistent interferents on the RLS of B(C6H5)4-K were investigated. The RLS intensity of the KB(C6H5)4 suspension was obtained in NaAc solution (0.50 M, pH = 8.0) and the addition of 0.5 mL of sodium dodecyl benzene sulfonate (5.05 μM) and 1.0 mL of tetraphenylborion sodium (1.0%). The Rayleigh scattering light intensity at the maximum peak of 567 nm was proportional to the concentration of potassium ion in the range of 0.20-1.60 μg mL-1 with a detection limit of 0.10 μg mL-1. To determine the feasibility of the proposed method, samples of water, drinks and serum were analyzed. The attained results were in agreement with the ion-selective electrode method. Good recovery was also obtained in a range of 95.10-107.02%. The sensitivity and selectivity of the RLS method are high enough to determine trace amounts of potassium ion without any significant interference from high levels of other components such as common anions and cations.