The data acquired in the framework of the global monitoring plan must enable a distinction to be made between variability representing true changes in the levels of persistent organic pollutants over time and differences that reflect variance derived from sampling and analytical procedures.
在全球监测计划框架内获取的数据必须能够区分体现持久性有机污染物随着时间而发生的真实变化和反映来自抽样和分析程序的差异。