Department of Pathophysiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
J Chromatogr A. 2021 Nov 8;1657:462570. doi: 10.1016/j.chroma.2021.462570. Epub 2021 Sep 22.
The purpose of this paper is to propose a simple method for daily inspections of a gas chromatography-mass spectrometry (GC-MS) system with an instrumental detection limit (IDL) as an indicator. A definition of DLs by ISO is 3.3σ where σ denotes the standard deviation (SD) of blank measurements. Estimation of σ is carried out according to the function of mutual information (FUMI) theory and actually with commercial software (TOCO19). An IDL which is a combination of a signal area, width and noise level is concluded to be a good indicator for daily inspections compared with each of its constituents. Methyl stearate is used as a standard material for the daily inspection of a programmed-temperature GC-MS system. A short chromatogram of 1800 data points (1.5 min) containing a target signal and background noise is fit for the IDL prediction by TOCO19. The relative SDs (RSDs) based on the theoretically estimated σ are shown to coincide with statistical results from repeated measurements within 95% confidence intervals. Column temperature is observed to affect IDLs through background fluctuation and then temperature-IDL relationship is examined in a range from 170 to 270 °C. Actual daily inspections over a month are demonstrated.
本文旨在提出一种简单的方法，使用仪器检测限 (IDL) 作为指标，对气相色谱-质谱联用仪 (GC-MS) 系统进行日常检查。ISO 对 IDL 的定义为 3.3σ，其中 σ 表示空白测量的标准偏差 (SD)。根据互信息 (FUMI) 理论和实际的商业软件 (TOCO19) 进行 σ 的估计。与各组成部分相比，IDL 作为一个信号面积、宽度和噪声水平的组合，被认为是日常检查的一个很好的指标。硬脂酸甲酯被用作程序升温 GC-MS 系统日常检查的标准物质。一个包含目标信号和背景噪声的 1800 个数据点（1.5 分钟）的短色谱图适用于 TOCO19 进行 IDL 预测。基于理论上估计的 σ 的相对标准偏差 (RSD) 与在 95%置信区间内重复测量的统计结果一致。观察到柱温通过背景波动影响 IDL，然后在 170 至 270°C 的范围内检查温度-IDL 关系。展示了一个月的实际日常检查。
