Validation of phosphorus compounds in seawater

Abstract

Phosphorus and phosphates, which determine biological development of organisms, are very important components of seawater. Their concentration in the coastal waters of the Baltic Sea is very low, which means that either an analysis of the samples should be performed within a 2 hour limit, or, they must be frozen immediately for further investigation [4; 6; 7]. If it is not possible to perform the analysis of the samples immediately, they should be frozen and shielded from solar radiation in order to halt the biological and biochemical processes. Such a procedure of using the samples, calls for a research method characterized by a low level of the lower limit of quantification, as well as adequate precision, repeatability, and accuracy. The aim of the carried out validation was to confirm the applicability of the method for determination of phosphorus compounds (total phosphorus, phosphates) in seawater for commercial purposes, in accordance with the recommendations of HELCOM [1;6]. Within the scope of this work, the lower limit of quantification was determined, and the precision, repeatability, accuracy, and reproducibility were identified. The studies confirm that the requirements for validation of the research methods were met.