ZHANG Yucheng, YOU Yuping, LI Wenting, WEI Zhenglong
Coal-based activated carbon is widely used due to its well-developed pore structure, excellent adsorption performance, and high mechanical strength. The accurate determination of impurity elements in activated carbon is of great significance for its application and research. In experiments, 5 g of the sample could be completely ashed after ashing at 800 ℃ for 2 h. The elements to be tested were fully extracted with 8 mL of aqua regia, and a small amount of ash residue did not influence the subsequent measurements. Cu 324.754 nm, Fe 259.940 nm, Zn 213.856 nm, Ni 231.604 nm, Pb 229.651 nm and Cr 267.716 nm were selected as the analytical lines of copper, iron, zinc, nickel, lead and chromium, respectively. The contents of copper, iron, zinc, nickel, lead and chromium were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The method for the determination of trace copper, iron, zinc, nickel, lead and chromium in coal-based activated carbon by ICP-AES with dry ashing and aqua regia extraction was established. The linear correlation coefficients of calibration curves for the measured elements were 0.999. The limit of quantification of copper, iron, zinc, and chromium were 0.000 02%, the limit of quantification of nickel was 0.000 05%, and the limit of quantification of lead was 0.000 2%, respectively. The contents of copper, iron, zinc, nickel, lead and chromium in four coal-based activated carbon samples were determined according to the experimental method. The relative standard deviations (RSD, n=7) of the results were between 1.0% and 7.9%, and the spiked recoveries of elements were between 92% and 112%.
