空氣中微量有害重金屬分析方法之研究

Analysis of Some Trace Harmful Heavy Metals in Airborne Particulates

蔡惠澤(H. T. Tsai) ； 呂進榮(J. R. Lu) ； 蕭家寧(C. N. Shiao) ； 陳漢恒(H. H. Chen)

《化學》 46卷4期 (1988/12) Pp. 239-250

https://doi.org/10.6623/chem.1988037

摘要

本篇利用極譜測定法(Polarographic Measurement)同時分析空氣粒狀物中鋅、鎘、鉛及銅等重金屬含量。使用高量空氣採樣器(High Volume Air Sampler)將空氣粒狀物吸附在玻璃纖維濾紙上，裁剪出3 × 3 cm大小，分別經(1)硝酸消化法、(2)硝酸苯取法及(3)硝酸與過氯酸微波消化法，三種方法前處理後，再以極譜測定法中之微分脈波陽極剝離伏安法(DPASV, Differential Pulse Anodic Stripping Voltammetry)進行分析，由結果顯示，三者分析所得之重金屬含量，並無顯著差異，然以硝酸苯取法為最省時、簡便及成本低廉，故本研究採用硝酸苯取法作為樣品中重金屬分析之前處理。消化液pH直接影響分析之靈敏度，本篇進一步研究結果顯示，樣品前處理後所殘留之酸液要儘量去除，並以0.2M醋酸鹽緩衝溶液(pH 4.76)當作協助電解質，使分析液之pH調至4.0~4.5，脈波高度(Pulse Height)設定為50mV，掃瞄速度為4mV/sec，以標準添加法在極譜儀之電解槽中進行DPASV分析，可得最佳結果，分析液的偵測極限值(LOD)分別為鋅(20ppb)、鎘(0.3ppb)、鉛(1ppb)以及銅(1ppb)，分析濃度的相對標準差(RSD)為5%，可進行超微量分析。

並列摘要

A simultaneous determination of zinc, cadmium, lead, and copper in airborne particulates by use of a polarographic method was studied. Airborne particulates were collected on glass-fiber filters using a high volume air sampler and were treated, respectively, with the following three methods: (1) digestion with nitric acid (2) extraction with nitric acid (3) digestion with a mixture of nitric acid and perchloric acid in a microwave oven. The samples were then analyzed by differential pulse anodie stripping voltammetry (DPASV). 0.2 M acetate buffer (pH 4.76) was used as a supporting electrolyte and the pH of the analytical solution was adjusted to 4.0-4.5 with this buffer. The instrument settings were as follows: pulse height at 50 mV and scan rate at 4 mV/sec. The qualitative and quantitative analyses were obtained finally with a standard addition method in polarographic cell. At the optimum condition, the limits of detection for zinc, cadmium, lead, and copper were 20 ppb, 0.3ppb, 1 ppb, and 1 ppb, respectively. The standard deviations of the concentrations in linear range were reproducible within ±5%. This method is applicable to the determination of concentrations at ppb levels.