[Selection of matrix modifier for GF-AAS determination of trace lead in soil watered with waste water and its application].

The rapid and direct method of selection of the matrix modifier for the determination of trace lead in soil watered with waste water by graphite furnace atomic absorption spectrometry under the best matrix modifier selected has been developed.The effect of the matrix modifiers including NH4H2PO4,(NH4)3PO4,NH4CI,Pd-Mg,NH4H2PO4+MgNO3+NH4NO3 etc.was determined by using graphite furnace atomic absorption spectroscopy.The results showed that NH4H2PO4 is the best matrix modifier for the determination of lead in soil watered with waste water,and the content of lead was determined by using 4.0 mg·L-1 NH4H2PO4 as a matrix modifier,ashing and atomization temperature of 850 ℃ and 1 600 ℃,respectively,and rectifying background.The relative standard deviation of the method was 2.6%,and the recovery was in the range of 92.4%-104%.