Abstract：
The quality of chemical analysis is an important aspect of passive sampling-based environmental assessments. The present study reports on a proficiency testing program for the chemical analysis of hydrophobic organic compounds in silicone and low-density polyethylene (LDPE) passive samplers and hydrophilic compounds in polar organic chemical integrative samplers. The median between-laboratory coefficients of variation (CVs) of hydrophobic compound concentrations in the polymer phase were 33% (silicone) and 38% (LDPE), similar to the CVs obtained in four earlier rounds of this program. The median CV over all rounds was 32%. Much higher variabilities were observed for hydrophilic compound concentrations in the sorbent: 50% for the untransformed data and a factor of 1.6 after log transformation. Limiting the data to the best performing laboratories did not result in less variability. Data quality for hydrophilic compounds was only weakly related to the use of structurally identical internal standards and was unrelated to the choice of extraction solvent and extraction time. Standard deviations of the aqueous concentration estimates for hydrophobic compound sampling by the best performing laboratories were 0.21 log units for silicone and 0.27 log units for LDPE (factors of 1.6 to 1.9). The implications are that proficiency testing programs may give more realistic estimates of uncertainties in chemical analysis than within-laboratory quality control programs and that these high uncertainties should be taken into account in environmental assessments.
摘要：
化学分析的质量是基于被动采样的环境评估的重要方面。本研究报告了一种能力测试计划，用于对有机硅和低密度聚乙烯（LDPE）被动采样器中的疏水性有机化合物以及极性有机化学综合采样器中的亲水性化合物进行化学分析。聚合物相中疏水性化合物浓度的实验室间变异系数（CV）的中位数为33％（有机硅）和38％（LDPE），类似于在该计划的前四轮中获得的简历。所有轮次的中值CV为32%。对于吸附剂中的亲水性化合物浓度，观察到更高的可变性：未转化数据为50％，对数转化后为1.6倍。将数据限制在表现最好的实验室并没有导致更少的变异性。亲水性化合物的数据质量仅与使用结构相同的内标弱相关，与提取溶剂和提取时间的选择无关。由性能最好的实验室进行的疏水性化合物采样的水性浓度估计值的标准偏差为有机硅的0.21log单位和LDPE的0.27log单位（1.6至1.9的因子）。其含义是，与实验室内质量控制程序相比，能力测试计划可能会对化学分析中的不确定性提供更现实的估计，并且在环境评估中应考虑这些高度不确定性。
