基于比色法和光谱法的土壤中磷的快速检测方法研究

Rapid determination of phosphorus content in soil based on colorimetry and spectroscopy

目的研发土壤中磷素的快速检测方法。方法针对土壤中磷含量的快速检测,利用比色法和光谱法构建了磷钼蓝反应的吸收曲线模型,并对一种智能土肥养份综合测试仪进行了测试。结果在检测波长为870nm时,将2.0 m L的26 g/L的钼酸铵溶液、1.0 m L的100 g/L抗坏血酸溶液和0.4 g/L的EDTA添加到酸性反应体系中,通过使用紫外-可见分光光度处理所测得的数据,可知磷溶液浓度与吸光度之间呈线性关系,得到线性回归模型为Y=0.01558X-0.1106,决定系数(r^2)=0.995。对这种智能土肥养份综合测试仪进行准确性测试,线性偏差在3%内,通过与所构建的线性回归模型的计算值进行对比,预测值误差在4%以内。结论所构建的线性回归模型是可用的,这种智能土肥养份综合测试仪可满足土壤中磷的快速检测要求。

Objective To research a rapid detection method of phosphorus in soil. Methods For rapidly detecting the phosphorus content in soil, the absorption curve model of phosphorus molybdenum blue reaction by using the colorimetric method and the spectral method was established, and a kind of intelligent soil nutrient tester was tested. Results At the detection wavelength 870 nm, by adding 2.0 mL 26 g/L ammonium molybdate solution, 1.0 mL 100 g/L ascorbic acid solution with 0.4 g/L EDTA in the reaction system, based on the data measured by a UV-visible spectrophotometer, the absorbance was linear with the concentration of the phosphorus solution, and the linear regression model was Y=0.01558X-0.1106, correlation coefficient （r2）=0.995. For the intelligent soil nutrient tester, the accuracy test was taken and the linear deviation was within 3%. And by comparing the calculated values with the established linear regression model, the predicted error was within 4%. Conclusion The established linear regression model is available and the intelligent soil nutrient tester can meet the requirements of the rapid detection of＆nbsp;phosphorus in soil.