Study And Determination Of Mineral Elements On Naval Orange And Its Planting Soil

Citrus cultivation occupies a very important position in the Chinese agriculture. As citrus fruits are widely planted in southern China, the citrus cultivation has become an important pillar industry. At present, the development of the sweet orange are focusing on the optimize of the conditions of the citrus cultivation in our country. The navel orange is the largest kind of sweet oranges cultivated in China today. The thesis here focused on the research of the navel orange and its planting soil including sixteen mineral elements which are closely related to agriculture and the environment, which has a very practical significance.In this thesis, we used Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Atomic Fluorescence Spectrometer (AFS) for the quantitative analysis of the content of mineral elements in the flesh, skin, leaves and planting soil of the navel orange. Reasonable methods from sample pretreatment to element determination were established. By investigating the distribution of 16 mineral elements in different parts of the navel orange and its planting soil, the enrichment of different mineral elements in the navel orange has been discussed.In the first part, according to the characteristics of the sample and the elements to be tested, we used four-acid to digest the soil which cultivated the naval orange. ICP-AES was used for the determination of the content of major elements, such as K, Ca, Mg, Fe, Mn and P. ICP-MS was used to determine the content of trace elements, such as Cu, Pb, Zn, Co, Cd, Cr, Mo and Ni. The volatile elements like Hg and As were dig-ested in aqua regia and determined by AFS. The results were verified by the national standard products, with the precision (n=7) of each element in the range of 1.01%-6.97% and the relative error (RE) less than 10%. The heavy metals in the 10 soil samples are below the environmental requirements on heavy metals of the pollution-free fruit producing area. Content of the mineral elements in navel orange origin soil are according to Fe>K>Mg>Ca>P>Mn>Zn>Cr>Pb>Cu>Ni>Co>As>Mo> Hg>Cd.In the second part, we used micro-waves to digest leaves, flesh and skins of the naval orange. ICP-AES was used to determine the content of major elements, such as K, Ca, Mg and P. ICP-MS was used to determinate the content of trace elements, such as Fe, Mn, Cu, Zn, Pb, Mo, Ni, Cd, Co, Cr and As. The volatile element like Hg was digested in closed hyperbaric environment, determined by AFS. The results were verified by the national standard products, with the precision (n=7) of each element in the range of 1.02%-8.90% and the relative error (RE) less than 10%. Through the actual sample testing, we found that there are many differences at the enrichment capability of mineral elements at different parts of the navel orange, and there is a big difference at the enrichment ability to absorb different elements in the soil at the same part of the navel orange.In this paper, the established methods can meet the analytical requirements of soil and plant samples. By effective sample pretreatment to reduce interference and optimize the test conditions and improve detection sensitivity, a variety of minerals elements can simultaneously be determined though a sample dissolution, which maximizes the efficiency and reduce the cost.