Determination of dissolved iron in seawater: A historical review

• Overview of analytical approaches for the determination of dissolved iron in seawater
• Iron biogeochemistry
• Sampling and sample treatment
• Detection methods
• Quality assurance of the data

This paper overviews the evolution of suitable analytical approaches for the determination of dissolved iron in seawater. The focus is on sampling and sample treatment, detection methods and quality assurance of the data. Iron is a vital trace element for the growth of marine organisms and is the limiting micronutrient for primary production in many parts of the world's oceans. The concentration of dissolved iron in seawater therefore influences the past and present day global carbon cycle and consequently Earth's climate. Hence it is important to understand the marine biogeochemistry of iron and quantify the spatial and temporal distribution of the element. In order to do this, it is essential that robust and validated methods with appropriate detection limits, precision and accuracy are available for the determination of iron species in seawater.