How Reference Materials Work

FIGURE 2.1 Comparison of two different analytical methods. (A) Original data set comparing the concentration of the analyte (sample) and a reference material (RM), (B) concentrations after correction for drift, and (C) concentrations after correction for reference material offset. 

The availability of reference materials or standards will not solve all the analytical problems faced by the marine community. In addition to using reference materials, the use of agreed-on common collection and analytical methods can also improve the chemical data being collected by oceanographers. Standardization of these methods minimizes the variability that may result from differences in laboratory procedure. A major disadvantage of method standardization, however, is that it can discour- 

Differenf sampling mefhods often result in collection of differenf com-ponenfs of the element or compound of interest. Most seawater samples are collected in bottles, filtered to remove particles and analyzed directly or after preconcentration of minor components. Particulate matter from fhe wafer column is collecfed by filtration or with sediment traps. Sediment samples are collected in cores that recover intact chronological sequences and are commonly subsampled, dried and groxmd to a powder. Pore waters are extracted from sedimenfs by squeezing or suction, dialysis, and centrifugation. 

---