Magnetic approach to normalizing heavy metal concentrations for particle size effects in intertidal sediments in the Yangtze Estuary, China.

In this study, mineral magnetic, particle size and geochemical analyses were conducted on intertidal sediments from the Yangtze Estuary to examine the feasibility of heavy metal concentrations normalization using magnetic techniques. Susceptibility of Anhysteretic Remanent Magnetization (chiARM), the ratio of chiARM to SIRM (Saturation Isothermal Remanent Magnetization) and susceptibility (chiARM/SIRM and chiARM/chi, respectively), and to a lesser degree, frequency dependent susceptibility (chifd), displayed significant correlations with the fine sediment fraction (<16 microm). The strong relationships between chiARM and heavy metals can be explained by the role of particle size and iron oxides in controlling metal concentrations. This study demonstrates that chiARM can be used to normalize for particle size effects as efficiently as common reference elements such as Al. Furthermore, the rapid and non-destructive nature of mineral magnetic measurement technique means that chiARM has a considerable application value in environmental quality monitoring and related studies.