Combination of NAA and TXRF: an improved method to detect elements in the moss technique

Abstract

Introduction: Due to industrial development, agriculture, and urbanization, environmental pollution is a serious problem worldwide. In particular, air pollution is becoming increasingly serious. To evaluate the impact of air pollution in major cities of the country, various methods of air collection and treatment and assessment through monitoring stations are being developed. However, the main disadvantage of the installation of monitoring stations is the cost of investment for operations, maintenance, and equipment. In this study, to reduce costs, Babular Indica moss was chosen as a biological indicator. Two techniques, NAA and TXRF, were combined to increase the number of trace elements detected in moss samples. Methods: A combination of two multielement analysis techniques, NAA and TXRF, are used to detect trace elements from atmospheric deposition in Barbula indica moss collected in Bao Loc, Vietnam. Results: The two methods are highly complementary, allowing us to determine 42 elemental concentrations in 11 moss samples. Twenty-nine elements were identified with NAA: Na, Mg, Cl, K, Sc, V, Cr, Mn, Fe, Co, Zn, As, Se, Br, Rb, Sb, I, Cs, La, Ce, Sm, Eu, Tb, Dy, Yb, Hf, Ta, Th and U. Twenty-four elements were identified with TXRF: Al, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Rb, Sr, Y, Ag, Sn, Sb, Ba and Pb. Eleven elements were identified by both techniques. Conclusion: This study shows that NAA and TXRF combine efficiently and provide a more comprehensive detection of trace elements in moss samples than is possible with either technique alone.