Determination of Available Lead in Greenhouse Soil by Solid Phase Dispersion Extraction Coupled with Atomic Absorption Spectrometry based on Primary Secondary Amine

In order to effectively evaluate the pollution status of available lead (Pb) in farmland environment, a method for the determination of available Pb in greenhouse soil by atomic absorption spectrometry with primary secondary amine (PSA) as solid phase dispersion adsorption material was established. In combination with neutral salt (such as 0.01 mol/L CaCl₂) extraction technology, neutral lead-containing aqueous solution was obtained. Based on the rapid adsorption of Pb in neutral environment and the rapid desorption of Pb under acidic conditions, the pretreatment method of sample enrichment and purification based on PSA was established by optimizing the parameters. The samples after enrichment and purification were determined by atomic absorption spectrometry. Results showed that the linearity of the method was good in the range of 0.010 ∼ 0.050 mg/kg (R² = 0.9990). The limit of detection was 0.0051 mg/kg and the limit of quantity was 0.017 mg/kg. The recoveries were 97.6% to 99.2% and the relative standard deviation was 0.79% ∼ 1.56% at the concentrations of 0.010, 0.030 and 0.050 mg/kg.