Sodium pyrophosphate is the most widely used extractant of Al bound to soil organic matter (Al-humus). However, its selectivity has been questioned, so that some authors have proposed the use of substitutional extractants. To evaluate the effectiveness of unbuffered Cu (CuCl2), La (LaCl3) and K (KCl) chlorides to extract Al-humus, soil material from 31 representative pedons of Spodosols and Quartzipsamments from sandy coastal plains of São Paulo State was evaluated. The results were compared with those achieved by sodium pyrophosphate. […]