Lately, organic farming has become a big part of the economy, and its importance is constantly growing. Since the organic farming is subject to a number of restrictions, not all agricultural inputs used in conventional agriculture can be used. Focusing on environment and human health protection, a number of inputs have been studied for acceptance in organic farming. Some of the most used inputs are ashes, composts, certain mineral fertilizers and manure. In order to be used as soil amendments, these inputs should meet a series of standards regarding the content on different elements or substances, to be sure that they are not harmful to health or to environment. Besides pesticides, antibiotics, dioxins and other substances, heavy metals are one of the most common contaminants in these inputs. Their quantitative analysis and correlation with current legislation should be one of the key factors in approving their use. These inputs are obtained from materials used in various industries and subject to different treatments such: combustion at 700-1000oC in the case of ashes, slow fermentation in the case of compost and manure or chemical synthesis for some fertilizers accepted in organic farming. This diversity leads to different methods of analysis, depending on the type of sample. Thus, analysis of certain inputs may require additional steps in the analysis protocol. For some heavy metals, there may be differences from the standard procedure, also. It should be mentioned that each method has its own limitations, and each class of instrumentation had a specific precision that depends of manufacturers. The accuracy of obtained result is strongly related to chemist’s decision in choosing proper and most suitable analysis method. This paper presents a list of methods used for heavy metals analysis in different matrices, found in recent studies. For the analytical metods of these elements, the sample preparation is an important step, which consists in sample conversion into a liquid form by various means. The methods for dissolving samples are also presented as they are described by the studies.

heavy metals, inputs, organic agriculture

sciences soil

Presentation: poster