This standard specifies methods for the extraction, with aqua regia, of trace elements and phosphorus from sludges and sludge products. The resulting solution is suitable for the determination of As, Cd, Cr, Cu, Hg, Ni, Pb, Se, Zn and P using spectrometric techniques. NOTE 1 With high solute concentrations in extract solutions, spectral interferences and background enhancement should be expected. NOTE 2 This method can be used for other elements except that portion of the elements bonded to silica.