气相色谱-质谱法检测邻苯二甲酸酯系统空白的探讨

Discussion of the system blank of detection of phthalic acid esters by gas chromatography-mass spectrometry

中文关键词:  邻苯二甲酸酯  空白干扰  气相色谱-质谱法

英文关键词:phthalic acid esters  blank interference  gas chromatography-mass spectrometry

中文摘要:

      使用气相质谱进行邻苯二甲酸酯检测时, 因分析系统中本身存在邻苯二甲酸酯, 产生系统空白值, 影响检测。在广大国家标准和方法学研究文献中均注意降低系统空白值并在计算结果中扣除系统空白值。但因实验过程中塑料制品和溶剂接触时, 邻苯二甲酸酯会不断溶出且溶出量不可控制, 难获得稳定系统空白值; 同时使用溶剂量过大产生浓缩操作时, 不但无法获得稳定系统空白值而且系统空白值因浓缩操作被放大。现阶段并没有国家标准和文献详细说明如何解决该问题。本文系统地描述了该问题的来源和产生的影响, 提出了4点解决意见: 尽量消除系统空白, 减少前处理步骤, 加入相同系统空白, 必须做空白实验并科学计算检出限。基于该问题的研究, 本文对在无空白实验的天然产物挥发油成分研究中检出邻苯二甲酸酯提出质疑。

英文摘要:

      When phthalic acid esters (PAEs) were detected by gas chromatography-mass spectrometry (GC-MS), the presence of PAEs in the analysis system resulted in a blank value of the system, which could affect their detection. In the literatures of national standard and methodologies, the system blank value is taken into account, and the system blank value is deducted in the calculated results. However, it is difficult to obtain a stable system blank value because the contact between the plastic and solvent during the process of the experiment, PAEs will dissolve continuously, and the amount of dissolving cannot be controlled. At the same time, the use of the solvent is too large resulting in a concentration of operations, not being able to obtain a system blank value, and the system blank value magnified by the concentration operation. At this stage, there is no literature or national standard detailing how to solve this problem. This paper systematically described the sources of the problem along with the impact of the problem and proposed 4 solutions: trying to eliminate the system’s blank value, reducing the pre-processing step, adding the same system blank value (must do blank experiment), and calculating the detection limit scientifically. Based on the study of the problem, this paper raises the question of the detection of PAEs in the study of volatile oil component of natural products without blank experiment.