VALIDATION PROCEDURE FOR TOTAL SULPHUR DETERMINATION IN COMPLEX FERTILIZER MATRICES USED IN ORGANIC FARMING.

Sulphur plays a vital role in plant nutrition. Its deficiency can have severe effects on crops, being essential in many biological processes. For an optimal supply it is necessary to know the content of elements of both the soil and the inputs used in agriculture. With the conversion from conventional to organic farming, an increasing number of analyses are needed on soil, the used inputs, and the obtained products. In general, sulphur determination methods are tedious and time consuming. This study proposes a dry combustion method for sulphur determination, which can gain ground due to the speed and ease of application. This elemental analysis method is sensitive and accurate, and can be applied for the determination of total S content in many types of sample matrices, including fertilizers. Different validation parameters were measured to ensure that the method can be used successfully applied and the procedure can be standardized, fully validated and nationally accepted. [ABSTRACT FROM AUTHOR]