代森铵在紫色土中吸附和解吸行为的流动注射化学发光法研究

采用恒温振荡平衡法,以流动注射化学发光快速分析代森铵的含量,研究了时间、土壤有机质、支持电解质、土壤pH值及代森铵浓度对代森铵在栽培涪陵榨菜紫色土中的吸附-解吸特性的影响.结果表明:随着时间的延长,代森铵在土壤中的吸附量和解吸量先升高后降低,吸附2 h后达到最大值402.15 mg/kg,解吸4 h后达到最大值192.41 mg/kg.土壤对代森铵的吸附量和解吸量随着有机质含量的增加而减少.支持电解质浓度升高,代森铵的吸附量和解吸量逐渐升高后再降低,NaNO3浓度为1.25 mol/L时吸附量达最大值979.47 mg/kg,NaNO3浓度为0.05 mol/L时解吸量最大值为202.23 mg/kg.土壤pH值升高有利于代森铵的吸附和解吸,pH为4时最大吸附量为145.55 mg/kg,pH为3时最大解吸量为102.50 mg/kg.随着代森铵实验浓度的增加,土壤对代森铵的吸附量和解吸量也增加,土壤的吸附量和解吸量与代森铵浓度的关系为直线型相关,代森铵的平衡浓度与吸附量符合指数关系,回归方程为lnωA(mg/kg)=0.494ρC(μg/mL)+3.838 5(n=3,r=0.993 0).研究结果对代森铵在田间的科学合理使用提供了理论指导.

Study on Adsorption and Desorption Behavior of Ambam in Purple Soil with Flow-injection Chemiluminescence Method

By the method of constant temperature oscillating equilibrium,the rapid determination of ambam content with flow-injection chemiluminescence has been performed.The ambam adsorption-desorption characteristics are influenced by the time,soil organics,supporting electrolytes,soil pH value and ambam concentration in purple soil of cultivating Fuling mustard tuber.The results showed that adsorption and desorption capacity of ambam in soil increased at first and then decreased as the time increased,the maximum reached 402.15 mg/kg after two hours of adsorption,the maximum reached 192.41 mg/kg after four hours of desorption.The adsorption and desorption capacity of ambam in soil decreased while the soil organic increased.Increasing supporting electrolyte concentrations,the adsorption and desorption capacity of ambam in soil increased gradually then decreased.The maximum of adsorption capacity was 979.47 mg/kg when NaNO3 concentration was 1.25 mol/L,the maximum of desorption capacity was 202.23 mg/kg when NaNO3 concentration was 0.05 mol/L.The increase of pH in soil was favor of ambam adsorption and desorption.The maximum of adsorption capacity was 145.55 mg/kg when pH was 4,the maximum of desorption capacity was 102.50 mg/kg when pH was 3.The adsorption and desorption capacity of ambam in soil increased as the ambam experimental concentration increased.The relationship between the adsorption and desorption amount of soil and the ambam concentration was in accord with the linear type,the balance concentration of ambam and adsorption capacity was in accord the exponential relationship,the regression equation was ln ωA(mg/kg)=0.494ρC(μg/mL)+3.838 5(n=3,r=0.993 0).The research result will provide the scientific use of ambam with the theoretic guidance.