Abstract:

Suitable detection methods to accurately and efficiently detect the soil exchange aluminum content were found. The differences, precision, accuracy and applicability of the exchange-neutralization titration of potassium chloride method, the aluminum reagent method and the chromoxane cyanine R method were analyzed. The results showed that there was no significant difference between the three methods. However, the precision of Chromoxane cyanine R method was better than that of the exchange-neutralization titration of potassium chloride method and the aluminum reagent method, and the average recovery rate of the wool-chromium-green R method was 99.28%, with a higher accuracy than the other two methods. The linear range of the chromoxane cyanine R method was 0 to 0.32 mg/L, and the linear range of the corresponding absorbent value was 0 to 0.778. The linear range of the aluminum reagent method was 0 to 0.8 mg/L, and the corresponding absorbent value range was 0.006 to 0.157. Compared with the aluminum reagent method, the linear range of chromoxane cyanine R method was smaller than that of the aluminum reagent method, but its absorbent value range was larger than that of the aluminum reagent method. The color rendering agent of the chromoxane cyanine R method was far from the absorption peak of the color rendering substance, the background interference was small, and the method sensitivity was higher. The average time of a single sample was 4.2 min, the detection efficiency was higher than that of the other two methods, and the operation was simple and the applicability was higher. Therefore, the chromoxane cyanine R method was recommended for the determination of soil exchange aluminum.

Key words: soil, exchangeable aluminum, exchange-neutralization titration of potassium chloride method, aluminum reagent method, chromoxane cyanine R method