Impact of changes in analytical techniques for the measurement of polychlorinated biphenyls and organochlorine pesticides on temporal trends in herring gull eggs.

摘要: Changes in analytical approaches during the tenure of monitoring programs for organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs) may affect estimates temporal trends. We used an in-house reference material to create multiplication factors adjust OC PCBs (Aroclor equivalents) Great Lake herring gull eggs analyzed using electron capture detection (1987-1997) be more equivalent mass spectrometric (1998- 2005) as well accompanying differences procedures. examined trends contaminant concentrations change point regressions, determine whether significant changes long-term were associated with methodology. The highest frequency occurrences shifted from 1997 (when methodology was altered) 2003 after data adjustment. explanatory power (r 2 ) regressions lower adjustment, although only margi- nally so (mean r difference ¼ 0.04). initial rates decline before points generally slower but any declines not significantly different. regression models did 83.3% cases. effects on interpretation eggs, negli- gible, minor relative magnitude changes. Environ. Toxicol. Chem. 2010;29:1476-1483. # 2010 SETAC