High-Resolution Fractionation after Gas Chromatography for Effect-Directed Analysis

Abstract

This research presents an analytical technology for highly efficient, high-resolution, and high-yield fractionation of compounds after gas chromatography (GC) separations. The technology is straightforward, does not require sophisticated cold traps or adsorbent traps, and allows collecting large numbers of fractions during a GC run. The technology is based on direct infusion of a carrier solvent at the end of the GC column, where infusion takes place in the GC oven. Pentane and hexane used as carrier solvent showed good results. Acetonitrile also showed good results as a more polar carrier solvent. Development and optimization of the technology is described, followed by demonstration in a high-throughput effect directed analysis setting toward dioxin receptor bioactivity. The GC fractionation setup was capable of collecting fractions in the second range. As a result, fractionated compounds could be collected into one or two fractions when 6.5 s resolution fractionation was performed. Subsequently, mixtures containing polycyclic aromatic hydrocarbons, of which some are bioactive toward the dioxin receptor, were profiled with a mammalian gene reporter assay. After fractionation into 96-well plates, we used our new approach for direct cell seeding onto the fractions prior to assaying which allowed dioxin receptor bioactivity to be measured directly after fractionation. The current technology represents a great advance in effect directed analysis for environmental screening worldwide as it allows combining the preferred analytical separation technology for often non-polar environmental pollutants with environmentally relevant bioassays, in high resolution.

High-Throughput Effect-Directed Analysis Using Downscaled in Vitro Reporter Gene Assays To Identify Endocrine Disruptors in Surface Water

“…Alternatively, GC/MS was successfully applied in EDA aimed at detection and identification of AhR ligands. 47 Therefore, further development of a complete identification strategy requires investigation of different ionization methods and implementation of a combination of chemical analysis techniques to detect the wide variety of compounds present in a sample. However, the presence of steroid hormones could be estimated by comparing calculated retention times to observed retention times of compounds measured on the used UPLC conditions ( Figure S5 ).…”

The role of analytical chemistry in exposure science: Focus on the aquatic environment

“…Complementary to the ubiquitously used LC fractionation, strategies for GC fractionation were developed in order to cover a larger part of the chemical space by focusing on volatile compounds. An example focused on the AhR-binding assay and the identification of PAHs (Pieke et al, 2013) in sediments. Improvement of the GC fractionation platform for bioactivity screening of toxic compounds was demonstrated by the analysis of a mixture of test pesticides, which after fractionation into a 384 well plate were tested in a post-column acetylcholinesterase (AChE) assay (Jonker et al, 2016).…”

Effect-directed analysis in environment research: current status and future challenges

“…在EDA流程中, 样品的分离和制备流程繁琐, 耗时 长, 因而发展快速制备和收集的自动化前处理方法是 提升EDA分析速度的有效途径. 样品的自动收集需要 引入自动化的分离制备装置, 收集装置应搭载玻璃 瓶、反应管、96孔甚至384孔板 [114,115] 等通用规格的批 处理容器. 除根据模式化合物保留时间进行收集外, 也 可基于特定时间间隔或特定体积等参数的分离制备策 略 [90] , 将各组分体积控制在微升剂量 [116] 或毫升剂 量 [75] .…”

“…然而GC的分离制备和组分收集 往往在开放的管状阱中进行, 气溶胶的形成容易导致 目标产物的损失 [118] . 针对GC分离制备的局限性, Kool 等 [114,119,120] 2005年, Jiang等 [82] 搭建了"成组/整合毒理学分析…”