AB-DTPA Extraction Of Soil Elements Adaptability Analysis And Determination Of Four Soil Pollution Elements Environmental Quality Standards In Preliminary Exploration

China has a vast territory.and the research in soil science is complex.This study using AB-DTPA extraction to analyze and determine the available contents of soil elements with ICP-OES for testing. The research collected Shanghai and21provincial administrative regions of our country’s eight types of soil samples for objects. To Compare with the common methods and CaCl2-DTPA extraction, we put forward reasonable suggestions for the adaptibility on AB-DTPA extract method to analyze the available contents of soil elements. Finally, it would make a preliminary exploration for using AB-DTPA extraction to analyze the available contents of copper, zinc, lead and cadmium as a commonly used method of soil environmental quality standards.(1)The available phosphorus contents extracted by the traditional method is slightly higher than AB-DTPA method normally. But AB-DTPA method can determine a variety of elements at the same time, and the data determined by two methods have good correlation, so the AB-DTPA method has more application prospects.CaCl2-DTPA extraction due to the extract amount too little, and is not suitable for the experimental application. So, for the multicomponent simultaneous determination, AB-DTPA extraction is more suitable for the analysis of soil available phosphorus.(2) CH3COONH4method as the traditional one to determine soil available potassium has a good accuracy and precision. AB-DTPA method has a little lower extractive efficiency than the classical method, and the correlation of the both is good. CaCl2-DTPA’s extraction value is low. Similar to the reason for the determination on available, AB-DTPA extraction is more suitable for the determination of soil available potassium in multielement extraction.(3) AB-DTPA method could be more effective on extracting available copper in soil than CaCl2-DTPA method, and the two groups of data were very significantly correlated. It shows that the two methods in extracting soil available copper have some common place on measurement principle, but AB-DTPA method’s extracting amount is obvious bigger. According to the recent results, AB-DTPA method is more suitable for the determination of soil available copper.(4) The results on analyzing the soil available zinc contents by AB-DTPA and CaCl2-DTPA method had some similarity to the analysis on soil available copper. But there also existed some unobvious differences in the different types of soil’s determination. According to the existing data, AB-DTPA method is better than CaCl2-DTPA method in this item.(5) Determining the soil available magnesium in low content, AB-DTPA extraction is superior to CaCl2-DTPA method on extracting amount and efficiency. The measuring data by two methods show significant correlation. Similar to the soil available copper and zinc determining results, the data of AB-DTPA method is better than that of CaCl2-DTPA method.(6) The difference of extracting amount and efficiency between the soil available manganese contents extracting by AB-DTPA and CaCl2-DTPA is few except moist soil. The measuring data by two methods show significant correlation. It is unable to determine the merits of the two methods on this item, and the difference of the moist soil need more research in the future.(7) Determining the soil available nickel in low content, AB-DTPA extraction is superior to CaCl2-DTPA method on extracting amount and efficiency. The result is similar as the determination of the soil available magnesium, but the degree of differentiation is more obvious. The two groups of data show significant correlation. So far, the AB-DTPA method is better about this item.(8) The extracting of the soil available iron by AB-DTPA method is significantly higher than that by CaCl2-DTPA method. The difference value between them fluctuate within a certain scope, and has no obvious regularity. The two groups of data show significant correlation. According to the results, AB-DTPA extraction is better than CaCl2-DTPA method for the soil available iron content.(9) AB-DTPA extraction is superior to CaCl2-DTPA method on extracting amount in determining the soil available sulphur content. The two groups of data show significant correlation. From this point of view, the AB-DTPA method is better than CaCl2-DTPA method.(10) AB-DTPA extracted soil available lead higher than CaCl2-DTPA. But the results in Shanghai area and in nationwide shown a little difference in regularity, and the reason need further research.At this moment, AB-DTPA method to analyze the soil available lead content is more dominant than CaCl2-DTPA method, but this point still needs further confirmation.(11) Extracting the available chromium content in soil by AB-DTPA method is greater than the one by CaCl2-DTPA extraction, and the two groups of data show significant correlation. For the existing data, AB-DTPA method is more dominant, and it has good extraction efficiency. But there are still some problems in the experiments need to be solve.(12) AB-DTPA extracted soil available cadmium higher than CaCl2-DTPA. And mostly the higher concentration is, the higher extraction amount and efficiency by AB-DTPA is. The two groups of data show significant correlation. It is not hard to see through the data, the determining of the soil available cadmium content by AB-DTPA method is more dominant.(13) Finally, we collected seven natural soil samples in four regions of China. According to the whole content on China soil environmental quality standards, we made the soil samples in pollution grade, and then analyzed the available contents of copper, zinc, lead and cadmium by AB-DTPA extracting method. At last, using the vailable contents results by AB-DTPA method made a soil environmental quality standards preliminary scheme. And the scheme is as follows: The Environmental Quality Standards on Soil Available Contents of Copper, Zinc, Lead, Cadmium in A Preliminary Scheme GradeFirstSecond Third Soil pH Natural Background<6.5>7.5Item WholeAvailable Whole Available Whole Available WholeAvailableContent Contents Content Contents Content Contents Content Contents Cadmium0.200.0820.300.110.600.0321.00.53Copper357.95029.410052.4400217.6Lead355.9250113.1350164.7500206.6Zinc10018.520059.8300120.7500197.8Note:The whole and available contents’s units are mg/kg.Extracting the four elements by AB-DTPA method usually reach16%～55%of the whole amounts.