GB/T 24991-2010 "Paper, board and pulps—Determination of lead content—Graphite furnace atomic absorption spectrometry" specifies the method for determining the lead content in paper, board, and pulps using graphite furnace atomic absorption spectrometry. It is applicable to samples containing recycled fibers after nitric acid wet digestion, with a detection limit of approximately 60 μg/kg. Samples are taken according to GB/T 450 or GB/T 740, digested, and then tested using the instrument. The standard outlines instrument conditions, the preparation of calibration curves, and calculation methods to ensure reliable detection of trace lead.