1. EPA Method 3051A, Method 3051A (SW-846) (2007) Microwave assisted acid digestion of sediments, sludges, and oils [S]. Washington, U.S. EPA
2. EPA Method 3052, SW-846 Test Method 3052 (1996) Microwave assisted acid digestion of siliceous and organically based matrices [S]. Washington, U.S. EPA
3. EPA Method 6020B, Method 6020B (SW-846) (2014) Inductively coupled plasma-mass spectrometry [S]. Washington, U.S. EPA
4. Liu X, Sun W, Wen T (2020) Determination of 23 metal elements in detailed soil survey samples by inductively coupled plasma-mass spectrometry with three acid stepwise digestion. Rock Min Anal 39(5):793–800
5. Mbaa B, Ppm B, Sp C, Itu A (2022) Health risk assessment of heavy metals concentration from soil; a case study of the mayo-dallah in southern area of chad. J Radiat Res Appl Sci 15(1):130–138