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在痕量有机物的分析中.在测定之前往往需要先进行富集或预浓缩,如进行疏水性树脂吸附、溶剂提取、水蒸汽蒸馏或真空蒸馏、液膜渗透等方法,但这些常见的富集方法对于挥发性有机物的痕量分析往往仍无能为力.这不仅因为不可能从样品中定量分离μg或ng水平的待测物质.而且由于会从分析环境中(溶剂和基体等)带入“异物”,使定性、定量工作反而掺入新的误差因素。 在这种情况下,不直接取样品进行分析,而是取与样品呈热力学平衡的气相进行分析,就可避免
In the analysis of trace organics, enrichment or preconcentration is often required prior to the determination such as hydrophobic resin adsorption, solvent extraction, steam distillation or vacuum distillation, liquid membrane permeation and the like, but these common enrichment Methods are often still not viable for trace-level analysis of volatile organic compounds, not only because it is not possible to quantify μg or ng of analytes of interest from a sample, but because “foreign matter” is introduced from the analytical environment (solvents and substrates, etc.) , So that qualitative and quantitative work instead of incorporating new error factors. In this case, instead of taking the sample directly for analysis, instead of taking a thermodynamic equilibrium with the sample, the gas phase can be analyzed to avoid