70 point Acetic acid curve by GC/FID demonstrates heterogeneity of variance in analytical data

These data are from a calibration of Acetic acid on a GC/FID instrument with a headspace autosampler with 70 calibrated points (10 points were targeted for each level, but replicates were weighed individually resulting in 70 unique amount points measured in mg). One major outlier was added after the fact to illustrate how outliers can pull the calibration model. These data illustrate problems with analytical data from chromatography experiments that largely go unnoticed because there's not enough data collected to see them, namely non-normal error, heteroscedasticity, and outliers.

There are 8 columns in the dataset, called "Level", "Amount", "Response", "ISArea", "DMIAmt", "STDAmt", "ISAmt", "ISAmount".

"Level" contains integer values corresponding to the specific vial prepared, numbered 1:70, not in that order.

"Amount" contains the amount of Acetic acid, in mg, in each vial run on the instrument, which was injected into the vial from a stock standard solution with a weighed concentration of Acetic acid and DMI. These data are sorted by "Amount".

"Response" is the gas chromatograph's (GC's) resulting area counts for the Acetic acid peak on each run.

"ISArea" is the GC's resulting area counts for the Ethylbenzene peak on each run.

The "Amt" columns are the balance weights for the internal standard solution, the reagent (DMI), and the stock standard solution added to each vial, measured in mg. These are not the Amounts of the individual standards in a vial.

"ISAmount" is the Amount of Ethylbenzene in the vial in mg.

本数据集源自于GC/FID仪器对乙酸进行的校准，采用顶空自动进样器，并设有70个校准点（每个级别针对10个点进行目标分析，但通过单独称量重复样本，最终得到70个独特的量级点，以毫克为单位进行测量）。在事后添加了一个主要异常值，以说明异常值如何影响校准模型。这些数据揭示了色谱实验分析数据中存在的问题，这些问题往往因收集的数据量不足而未被发现，包括非正态误差、异方差性和异常值。

数据集中包含8列，分别为“级别”、“量”、“响应”、“ISArea”、“DMIAmt”、“STDAmt”、“ISAmt”和“ISAmount”。

“级别”列包含对应特定试管制备的整数值，编号为1至70，并非按照该顺序排列。

“量”列包含每个试管中乙酸的质量，以毫克为单位，该乙酸由含有乙酸和DMI（对二甲苯）的储备标准溶液注入，并经过称量以确定浓度。这些数据按照“量”进行排序。

“响应”列是每次运行中气相色谱（GC）对乙酸峰的面积计数。

“ISArea”列是每次运行中GC对乙苯峰的面积计数。

“Amt”列是添加到每个试管中的内标溶液、试剂（DMI）和储备标准溶液的平衡重量，以毫克为单位。这些并非试管中单个标准物质的量。

“ISAmount”列是试管中乙苯的量，以毫克为单位。